AWUS01 KWNH 060100
FFGMPD
TNZ000-KYZ000-ILZ000-MSZ000-MOZ000-ARZ000-060658-

Mesoscale Precipitation Discussion 0158
NWS Weather Prediction Center College Park MD
859 PM EDT Tue May 05 2026

Areas affected...Portions of the Lower to Mid-Mississippi Valley

Concerning...Heavy rainfall...Flash flooding possible

Valid 060058Z - 060658Z

SUMMARY...Increased thunderstorm coverage along and ahead of a
migrating cold front will intersect a modestly unstable
environment capable of enhanced rates that could lead to localized
flash flooding. Total rainfall between 2-4" will be plausible in
the hardest hit areas with the greatest threat aligned within the
Memphis metro into portions of northeast Arkansas.

DISCUSSION...Current radar and satellite composite indicates the
advancement of a cold front to the north and northwest of the
Lower Mississippi Valley with a weak surface low progged near the
OK/AR border. Increased 85H wind field ahead of the surface wave
is indicative of a budding LLJ that will act to enhance regional
shear profiles and low-level convergence along and ahead of the
advancing cold front. Latest HRRR/RAP boundary layer convergence
signal is quite robust across north-central AR, extending
northeast into western TN with a general alignment right along the
front as it slowly advances to the south-southeast. Prevalent
moisture ahead of the front is well-documented as dew points
nestle into the mid and upper-60s with areal PWAT anomalies
settled between 1-2 deviations above normal according to the
GEFS/NAEFS anomaly outputs. Modest MUCAPE on the order of 750-1500
J/kg will be positioned ahead of the cold front which when coupled
with the deep layer moisture will entice heavier precip cores
capable of producing hourly rates between 1-2"/hr in the strongest
cells.

There is a general agreement on a crescendo of convective
development between now and 06z this evening with the heaviest
precip focused across east-central AR extending into southwestern
TN. This would put the Memphis metro corridor and surrounding
counties in the best convergent pattern capable of the higher
rainfall totals which was expressed within the latest HREF
neighborhood probabilities indicating the higher probs for >2"
centered over southwest TN. This area has already experienced a
period of heavier rainfall earlier today leading to some priming
of the top soil layer which would make for a bit of an easier time
to initiate run off capabilities. The urban center of Memphis also
draws for an enhanced run off threat, so the coupling of the
priming and impervious surfaces should give way to a greater flash
flood threat in the metro, at least from a local perspective.

Thunderstorms will continue to slowly migrate southeast with the
cold front through the evening with a wave of convection likely to
extend back over the I-30 corridor in AR. The approach of the weak
surface low will also provide a localized convergence footprint
capable of heavy rainfall and flash flood prominence as the low
continues its progression east-northeastward. This signal will
likely carry beyond the 6hr period with impacts likely to occur
even beyond 06z for areas further south and east across AR/TN/MS.

Kleebauer

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-63y0jxHNe6PbJnpBgj-GkcnJmfYgcEmX2C68TeyzKVV-JDRuhXr98FJWxalN34FMZwr= 4rzP7UPlJZRksYtYCIYSiy4$ for graphic product...

ATTN...WFO...LZK...MEG...OHX...PAH...

ATTN...RFC...ORN...TIR...TUA...NWC...

LAT...LON 37038915 37008852 36948798 36938750 36708711=20
36388709 36078757 35738819 35448852 35268871=20
35068903 34848960 34659053 34579165 34639272=20
34929319 35459315 35849270 36269156 36429094=20
36619044 36768998 36878949=20

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AWUS01 KWNH 060722
FFGMPD
TNZ000-ALZ000-MSZ000-ARZ000-061320-

Mesoscale Precipitation Discussion 0159
NWS Weather Prediction Center College Park MD
321 AM EDT Wed May 06 2026

Areas affected...Central AR, Southwest TN, Northern MS

Concerning...Heavy rainfall...Flash flooding possible

Valid 060720Z - 061320Z

SUMMARY...Convection developing along and just north of a
southward-moving surface front will pose an isolated flash flood
threat through 13Z across portions of central AR into southwest TN
and northern MS. Fast storm motions parallel to the boundary will
allow for brief periods of training, with localized rainfall
totals of 2 to 3 inches possible where upscale growth occurs.

DISCUSSION...Regional radar imagery and surface observations
indicate convection developing along and north of a surface
frontal boundary draped across central Arkansas into southwest
Tennessee and northern Mississippi. Ascent is being heavily driven
by strong frontogenesis in the surface to 925 mb layer, which is
fostering enhanced low-level convergence. Concurrently, strong 925
mb moisture transport is being directed squarely into this frontal
zone, providing ample fuel for precipitation production.

The thermodynamic environment is becoming increasingly supportive
of robust updrafts along the boundary. Recent mesoanalysis
indicates a modest destabilization trend, with MUCAPE values
increasing by roughly 400 J/kg over the past 3 hours. Absolute
MUCAPE values now range from 1000 to 2000 J/kg. The warm sector
ahead of the boundary remains strongly capped, effectively
confining the convective development and heavy rainfall threat to
the frontal zone itself or the immediate cool side to its north.

Individual cell motions are relatively fast from west to east.
Because these motions are largely aligned parallel to the
orientation of the frontal boundary, there is an inherent risk for
training convection. However, a key mitigating factor is the
continuous southward progression of the front itself, which should
serve to limit the duration of this training at any single
location.

Ultimately, the flash flood risk will depend heavily on the degree
of upscale convective development along and just behind the
advancing front. If sufficient consolidation occurs to maximize
the brief training window, localized rainfall totals of 2 to 3
inches are possible, which could overwhelm sensitive basins or
poor drainage areas. There are some signs of this beginning to
occur across central AR. Given the progressive nature of the
boundary and the fast individual cell motions, the overall flash
flood threat should generally remain isolated through 13Z.

Chenard

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7IZMgGMW-dCFh9n9aLw6av-YCpHQiznnrA9h3YptSbuiqDg52PNhquLFeVGSJCB9Hr-G= Znd7P_G0Kv1FU2fo9q4033M$ for graphic product...

ATTN...WFO...HUN...LZK...MEG...OHX...

ATTN...RFC...ALR...ORN...TUA...NWC...

LAT...LON 35868789 35698689 35168615 34728757 34448992=20
34179209 34079284 34179331 34299379 34579379=20
34989272 35239181 35688956 35768878=20

=3D =3D =3D
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AWUS01 KWNH 061927
FFGMPD
ALZ000-MSZ000-LAZ000-TXZ000-070125-

Mesoscale Precipitation Discussion 0160
NWS Weather Prediction Center College Park MD
325 PM EDT Wed May 06 2026

Areas affected...Far East TX through much of LA, MS, and western
AL

Concerning...Heavy rainfall...Flash flooding possible

Valid 061925Z - 070125Z

SUMMARY...Increasing threat of heavy rainfall with scattered to
widespread convective development initiating ahead of a
slow-moving cold front to the north. Primed environmental
conditions will allow for locally enhanced rainfall rates with
totals approaching 2-4" in some of the heavier cells that develop.
Isolated to widely scattered flash flooding will be possible.

DISCUSSION...Radar and satellite composite indicate a rapidly
growing convective initiation regime across areas of far eastern
TX extending northeast through LA/MS/AL. A cold front situated
over east TX through the Lower Mississippi Valley into the
northern tier of AL/MS will continue to slowly sag southward with
multiple areas of surface low pressure riding along the front in
the process. First surface low is analyzed across east TX with an
enhanced convergence pattern centered to the east of the low as
flow remains backed within the area situated between the TX/LA
border north of the Lower Sabine. Area MUCAPE is between 2000-3000
J/kg in this location according to the latest mesoanalysis along
with a moisture rich environment signaled by PWAT anomalies ~2
standard deviations above normal, a testament to a deep moist
convective environment suitable for locally enhanced rates and
potential for areas to see a quick couple inches of rainfall
during impact. 12z HREF was quite robust in the signal for
neighborhood probs of >1"/hr at times with a swath of 50-80% probs
located from the TX/LA line to points northeast through much of MS
into western AL. This correlates well with the boundary layer
convergence anticipated along and ahead of the approaching cold
front as the front approaches the fairly buoyant environment
further south.

The other area of interest within this setup is across northeast
MS into northern and western AL where the second surface wave will
continue to migrate to the northeast leading to a general foci for
convective development under the lows influence. Like areas
further southwest with the low in TX, there will be an narrow
corridor of enhanced convective potential within the locally
backed flow centered just to the east and northeast of the surface
wave's trajectory. The good news for this area is the front will
migrate through the region and begin to provide a drier theta_E
advection pattern on the backside of the low. However, the narrow
corridor of elevated theta_E's analyzed over northeast MS into
northern AL should still be sufficient for locally heavy rain
cores, noted very well within the latest 18z WoFS iteration that
is consistent with its signature of a band of heavier convection
forming in the aforementioned area.

The general setup for the entire area encompassed by the MPD will
be suitable for heavy precip totals between 2-4" in the hardest
hit areas with hourly rates between 1-2"/hr in the strongest
cells. This is well-documented on the consistent signatures via
the latest HRRR iterations, as well as the noted prob fields from
the 12z HREF where CAMs were consistent in the potential between
now and 01z in this corridor of the Southeastern CONUS.

Kleebauer

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4xgFQaQWgnaGyzrHGv0cZaz6XRVw-aumE4Cx9XYIX3ZuO3zj74cHtpdiLAv0gi_yr_oi= M46WdOs1EpE3OyKaf3J3U8Q$ for graphic product...

ATTN...WFO...BMX...HGX...HUN...JAN...LCH...LIX...MEG...MOB...
SHV...

ATTN...RFC...ALR...FWR...ORN...NWC...

LAT...LON 34728734 34258671 33348667 32618703 32048788=20
31728853 31468925 31229027 30869157 30589263=20
30439371 30399448 30879466 31379435 31879363=20
32109284 32399221 32619180 32909112 33249038=20
33698949 34238869 34588778=20

=3D =3D =3D
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AWUS01 KWNH 070101
FFGMPD
GAZ000-ALZ000-MSZ000-LAZ000-070658-

Mesoscale Precipitation Discussion 0161
NWS Weather Prediction Center College Park MD
859 PM EDT Wed May 06 2026

Areas affected...Central LA, Central and Southern MS/AL, and
Western GA

Concerning...Heavy rainfall...Flash flooding likely

Valid 070058Z - 070658Z

SUMMARY...Widespread thunderstorms will spread across the
Southeastern U.S. with a heightened threat of training as the cold
front continues to advance south through Louisiana, Mississippi,
Alabama, and Georgia. Accumulations of 2-4 inches of rainfall,
locally higher, are expected in areas of training leading to
likely flash flooding as soils are primed from earlier rainfall.

DISCUSSION...The 21z surface analysis continues to convey the
methodical southern motion of a now wavy quasi-stationary front
situated across the northern half of the Southeast CONUS. Multiple
surface lows are embedded within the frontal structure with one
still slowly ejecting eastward out of east TX, and the other
analyzed over northern AL. The former area of low pressure will
play a significant role in the convective evolution this evening
as the low-level convergence regime amplifies into something more
appreciable in regards to focusing convection over a more defined
area. CAMs continue to be steadfast in their representation of the
environment and synoptic scale evolution providing a solid
consensus for where the heaviest rainfall will transpire as we
move through the overnight period.

Current environmental status remains very favorable with
prevailing axis of elevated MLCAPE between 1000-2000 J/kg situated
ahead of the stationary front from southwest LA through western
GA. Deep layer moisture remains prevalent over much of the
Southeast with PWAT anomalies solidly between 2-3 standard
deviations above normal. Mean layer flow will run more parallel to
the boundary as it slowly migrates southward through the evening
leading to general convective forward propagation to overlap with
each other as they progress through the evening. Upper level
dynamics remain favorable, as well as a broad upper trough passing
to the north will maintain reputable large scale ascent within the right-entrance region of a 140kt upper jet crossing through the
Mississippi Valley. Nocturnal LLJ centered over southern MS
extending into AL will only provide increasing low-level
convergence and relevant bulk shear to maintain stronger
mesocyclone cores that can provide heavier rainfall over extended
periods of their life cycle(s).

Considering the above factors, rainfall rates this evening will
likely exceed 1"/hr in the stronger cells with 2-3"/hr well within
reach despite the loss of diurnal destabilization. Even as cells
begin the merger process and become a more cohesive, multi-cell
structure, heavy rain with 1-2"/hr areal averages will certainly
be plausible which will lead to widespread areas of 2-4" of
rainfall with locally higher totals possible as inferred by
low-end HREF probabilities for >5" centered over southeast MS into south-central AL to the AL/GA line. Secondary maxima could also
occur further northeast into northwestern GA, including
potentially close to the Atlanta metro where some CAMs are
relatively bullish with heavy rain prospects in the urban
corridor. The greatest threat is still likely further south and
west, but the setup is still relevant for those areas downstream
into the northwest quarter of GA. Areas of highest concern are
likely within the confines of Laurel, MS over to Montgomery, AL to
near Columbus, GA spreading 50-75 miles either side of that line.

Kleebauer

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9juSkWDhsmkz1MRnOj1yQ-t0fCsAXwyH-PM2n0P0IkqgFYj8RZ7-4PRxOoWPXAvWT3TO= oY0eMYkM_EgNAjVfptgmZ0E$ for graphic product...

ATTN...WFO...BMX...FFC...HUN...JAN...LCH...LIX...MEG...MOB...
SHV...

ATTN...RFC...ALR...ORN...NWC...

LAT...LON 34908514 34808461 34628420 34308401 33938385=20
33418392 32848431 32378464 32068520 31748605=20
31378698 31168791 31038901 30928992 30959150=20
31079277 31769269 32429175 32879071 33218969=20
34198708 34458635 34708575=20

=3D =3D =3D
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AWUS01 KWNH 070650
FFGMPD
FLZ000-GAZ000-ALZ000-MSZ000-LAZ000-071247-

Mesoscale Precipitation Discussion 0162
NWS Weather Prediction Center College Park MD
249 AM EDT Thu May 07 2026

Areas affected...southern Alabama, far southwestern Georgia,
southeastern Mississippi

Concerning...Heavy rainfall...Flash flooding possible

Valid 070647Z - 071247Z

Summary...Areas of training thunderstorms are likely to continue
for the next several hours, with isolated instances of flash
flooding possible through 13Z/8a CDT.

Discussion...Scattered thunderstorms continue to move eastward
across the discussion area at around 40 knots while producing
areas of 1-2 inch/hr rain rates. The heaviest of rain rates are
currently displaced just south and east of where heavier rain fell
earlier today near Montgomery/Selma and near Collins, MS --
although deep convection continues to redevelop across
southeastern Mississippi along and just ahead of a synoptic front
extending from Baton Rouge through Meridian to near Birmingham.=20 Moist/unstable thermodynamic profiles and low-level/850mb
confluence will continue to support new updraft development across
southeastern Mississippi for several hours, with storms spreading
eastward through southern Alabama and far southwestern Georgia
through 13Z this morning.

Any flash flood risk within this regime will exist 1) where
convective training is most pronounced within the discussion area
and 2) where scattered convection can repeat across the Montgomery/Selma/Collins areas where prior rainfall has lowered
FFGs to near zero. Given the magnitude of prior rainfall in some
of these areas, flood impacts may still be ongoing and could be
exacerbated locally. New instances of flash flooding are also
possible. Local rainfall totals of 2-3 inches are likely through
13Z - particularly from Laurel/Hattiesburg eastward to Troy, AL
and areas near/south of Columbus, GA.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!547HLYTGdFVIf4LHXnULs5IQlRg9YYGJNsX4HsCB5q50E3nC0aZU0ZbAVESd0Tm5JHpO= RpmZ09Ex7eF54TfgUkI7470$ for graphic product...

ATTN...WFO...BMX...FFC...JAN...LIX...MOB...TAE...

ATTN...RFC...ALR...ORN...NWC...

LAT...LON 33548583 33178442 32328375 31438378 30878454=20
30908730 30778950 31188994 31668978 32348879=20
33178731=20

=3D =3D =3D
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AWUS01 KWNH 081146
FFGMPD
MSZ000-LAZ000-TXZ000-081700-

Mesoscale Precipitation Discussion 0163
NWS Weather Prediction Center College Park MD
745 AM EDT Fri May 08 2026

Areas affected...Southeast Texas...Southern Louisiana...Southwest Mississippi...

Concerning...Heavy rainfall...Flash flooding possible

Valid 081145Z - 081700Z

SUMMARY...Early morning elevated thunderstorms with potential to
train this morning pose narrow axis of 2-4" totals and isolated
flash flooding concerns near urban and areas of recent heavy
rainfall.

DISCUSSION...GOES-E WV suite depicts a broad positive tilt closed
low across the southwest with a nicely shaped anti-cyclonic
downstream shortwave ridge across central TX into confluent flow
regime across the Lower Mississippi Valley into the Tennessee
Valley. This places the surface front stalled along south and
parallel of the Texas Gulf Coast before angling northward to a
weak surface wave south of Houma, LA. CIRA LPW denotes the
anomalously high sfc to 850mb moisture pooled along and north of
the front generating a very tight gradient across southeast TX and
across central LA. The 850-700 and 700-500mb layers are also
complimentary to total PW values aligned across the area of
concern that values of 1.75-2" exist between the surface front and
the surface coastal pressure trof that goes from KNOG to KTME
before crossing that tight PW gradient near KJAS to KAQV in
western LA.

Surface to boundary layer onshore flow is providing weak but
sufficient WAA before veering to the southwest through the 850mb
layer to provide sufficient convergence and isentropic ascent
across the boundary to access the larger well of conditionally
unstable air with MUCAPES of 1000-1500 J/kg...which extends
eastward along and south of the PW gradient along and north of
I-10 through E LA into S MS. As such, RADAR and GOES-E 10.3um
depicts solid convective initiation along and south of the tight
gradient which further helps to steepen vertical ascent plane.=20
The overall depth of moisture is already supporting isolated to
scattered .5-1"/hr rates but this will continue to increase with
coverage and moistening of the mid-level profiles. Additionally,
with some surface heating, a few nearer surface based cells with
higher rate potentials to 1.75-2"/hr may develop over the next 3-4
hours along or even south of the I-10 corridor.

As mentioned, the deeper layer flow flattens west to east into the
confluence downstream generally parallel to the boundary/ascent
plane to support a favorable opportunity for repeating/training
(especially further east into LA). This may allow for narrow
streaks of 2-3+", with an isolated 4" total not out of the realm
of possibility. Generally sandy soils and naturally high FFG in
the region from overall drought should help to mitigate most of
the heavy rainfall. However, there are is a axis of reduced FFG
values especially from Vernon to Rapides to Concordia parish in LA
and portions of SW MS that are recovering from heavy rainfall
36-48rs ago as well as a number of prone urban centers along the
area of concern that would be more susceptible to possible
incident or two of localized flash flooding this morning.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!43JR2EjvKq_jQoiS8RC6iUhu4LPNsWcKcFQbrska-jrXiE-1twdbCM1a0Q4QEXPzapcP= RrLTQOglDchUGoLCPjpO9WE$ for graphic product...

ATTN...WFO...FWD...HGX...JAN...LCH...LIX...SHV...

ATTN...RFC...FWR...ORN...NWC...

LAT...LON 31669219 31519034 31208953 30788938 30308968=20
30129069 30159225 30159283 30059469 30149581=20
30449631 30959639 31329594 31559489 31629321=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
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AWUS01 KWNH 081625
FFGMPD
ALZ000-MSZ000-LAZ000-082230-

Mesoscale Precipitation Discussion 0164
NWS Weather Prediction Center College Park MD
1224 PM EDT Fri May 08 2026

Areas affected...Southern Louisiana...Southern
Mississippi...Coastal Alabama...

Concerning...Heavy rainfall...Flash flooding possible

Valid 081630Z - 082230Z

SUMMARY...Continued risk of possible urban and localized flash
flooding with new axis of training development as initial band
slowly weakens across S MS/S AL. Streak of 2-4" totals and
occasional rate over 2"/hr along I-10 corridor.=20

DISCUSSION...Very little has changed in the overall synoptic
environment and placement of the surface stationary front parallel
to the TX coast before angling toward the SE portions of LA before
likewise angling eastward. The upper-level divergence has
slightly up-ticked as well just downstream of the synoptic
shortwave ridge in E TX, but the low-level flow has increased
about 10-15 kts from the southwest particularly in the boundary
layer to 850mb. This has resulted in increased convergence at a
slightly lower elevation across far SE TX into SW LA and with
greater boundary layer depth of moisture and its flux, intensity
of rainfall rates will be increasing as well with occasional
breaches of the 2"/hr rates given TPW nearing 2.0" (loaded mainly
below 850mb) and MUCAPEs over 1000 J/kg. As this new has
strengthend, the more elevated convection has been robbed and
coverage is reducing along the upstream edge with only the leading
edge convection maintaining across S MS, trending toward far S AL.


The broader west to east ascent plane has also increased the
overall coverage to allow for steering flow to support slightly
better training/repeating profiles in proximity to the I-10
corridor. Hi-Res CAMs have struggled a bit with the overall
orientation and convective initiation, but the last few RRFS
solutions appear to be most in line with the recent trends
followed by the 12z ARW. This suggests further training potential
along I-10 with an eventual weak cold pool to perhaps deviate cell
motions a bit south of due east alluding the potential for
intersecting even as far south as I-8 increasing intersection with
the prone urban regions of the area.=20

Unlike, further north in central LA/S MS, I-10 and south have been
missed in prior events and FFG values are naturally at the highest
values and may still be out of reach for broader flash
flooding/rapid inundation potential, though isolated localized
exceedance is possible. However, intersection with urban centers
is more likely and therefore flash flooding remains more probable
in those areas through the late afternoon/early evening.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_VWBFItyO23ZtJog41Nwsw-8rqH4Ayaz11KtYmqdGVjSQ3tQY3yh1uBdt87CZ58pMHBH= aIHNNHW_jxwhmKqGqplJUkg$ for graphic product...

ATTN...WFO...JAN...LCH...LIX...MOB...

ATTN...RFC...ALR...ORN...NWC...

LAT...LON 31368957 31228831 31018769 30268757 29978891=20
29578976 29789113 29879206 29969301 30209360=20
30789342 31089261 31349100=20

=3D =3D =3D
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AWUS01 KWNH 090914
FFGMPD
FLZ000-ALZ000-MSZ000-LAZ000-091512-

Mesoscale Precipitation Discussion 0165
NWS Weather Prediction Center College Park MD
512 AM EDT Sat May 09 2026

Areas affected...central/southern Louisiana, southern Mississippi,
southern Alabama, and far western Florida Panhandle

Concerning...Heavy rainfall...Flash flooding possible

Valid 090912Z - 091512Z

Summary...Areas of convection (with scattered
mergers/backbuilding) will pose a flash flood risk through 15Z/10a
Central this morning.

Discussion...Scattered convection has organized into a mix of
clusters and linear segments along a couple axes -- one extending
from near Natchitoches, LA to Jackson, MS to west-central AL and
another, more scattered band from near Natchez, MS to near
Slidell, LA. These cells were moving eastward at an appreciable
clip (30-35 kt), but were being sustained by appreciable mid-level
instability and 1.75 inch PW values. The loosely organized nature
of the cells was supporting occasional training and mergers, with
spots of 1-2.5 inch/hr rain rates focused primarily in northern
Louisiana over the past half hour to hour. FFGs in this region
were high (around 3-4 inch/hr), suggestive of only an isolated
flash flood risk (at best) in the short term.

With time, cells will migrate/evolve east-southeastward toward
portions of southern Mississippi that have received 3-6 inches of
rainfall over the past 72 hours. Soil moistures are wetter here,
and FFGs are somewhat lower (near 2 inches/hr in spots). Portions
of southern Louisiana have lower FFGs from prior rain (around 1
inch/hr) as well. The slow northward drift of a remnant outflow
from earlier convection (and attendant surface-based instabilty)
will probably interact with ongoing convection favorably for more
mergers and localized training as cells migrate
east-southeastward, with rain rates over 2 inch/hr expected in a
few spots (supported by abundant PW values). Areas of flash
flooding are possible, and the overall risk will increase in the
aforementioned areas (esp. southern LA/MS) between 10Z-15Z this
morning.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9ZPHGrCo880vNxE2xZX0vXQcnQSi5Mda1AJTNWBlQcRSG2pf8LyinmjcgWhZy1nE0bVR= udUPzDc1cSTJMSyXyv-N29M$ for graphic product...

ATTN...WFO...BMX...JAN...LCH...LIX...MOB...SHV...TAE...

ATTN...RFC...ALR...FWR...ORN...NWC...

LAT...LON 32938887 32498711 32278640 31948583 31048582=20
30548756 30058985 30019105 30469219 30889319=20
32419374 32689303 32649166 32769048=20

=3D =3D =3D
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AWUS01 KWNH 091658
FFGMPD
LAZ000-TXZ000-092230-

Mesoscale Precipitation Discussion 0166
NWS Weather Prediction Center College Park MD
1258 PM EDT Sat May 09 2026

Areas affected...Southern LA...Far Southeast TX..

Concerning...Heavy rainfall...Flash flooding possible

Valid 091700Z - 092230Z

SUMMARY...Continued flash flooding potential with over-running in
southern LA. New convection across SE TX/W LA may be more
pulse-like with cell mergers capable of a very quick 2" burst.

DISCUSSION...Regional RADAR mosaic and surface observations depict
orthogonal ascent from the core of the moisture axis (TPW at
2-2.15") over cold pool centered over SE LA. Surface easterlies
further help sharped the boundary with additionally rain-cooled
air from the over-running convection, as such a few more hours of
scattered isentropic convection will likely occur. The
orientation of the ascent streamers will allow for narrow streaks
of enhanced totals with values of 2-3.5" probable, falling over
areas already affected with 2-3" so far this morning. However,
the parent shortwave from the northern stream now, well displaced
into the Southeast over AL/GA, is still sliding east-southeast and
the moisture axis and remaining weak LLJ will continue to drift
southeastward relative to the current activity further into the
Bayous of S central and SE LA.

However, upstream energy in the form of a strengthening right
entrance region to a 100kt 3H jet streak can be seen by well
defined anticyclonically curved upper cirrus pattern over far E TX
into NW LA at this time. At the surface the old outflow boundary
remains weakly defined across west-central to central LA and will
likely remain the focus of some convective activity.=20
Unfortunately, the influence of the downstream shortwave is
pooling away the main warm-conveyor belt and there only remains a
narrow pocket of enhanced surface to 850 and to 700mb per CIRA LPW
with drier air mixing in aloft. This helps with some increased
instability as 2000 J/kg of MLCAPE pool exists across E TX.=20
Weaker flow into the complex, even with backing low level flow
responding to the divergence aloft, suggests convective mode may
be a bit more pulse-like with scattered clusters and propagation
along collapsing outflow boundaries through the afternoon. The
amount of moisture should allow for solid efficiency with spots of
2-2.5"/hr (similar totals) possible across SE TX and West-central
LA. Flash flooding will remain an isolated potential given
recent heavy rainfall, wetter soils (especially east in LA) or
over urban locales. As such, while the coverage and overall
intensity is reducing; the risk of a few incidents of flash
flooding remain across the MPD area of concern through late
afternoon.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8hmqYYdh83CPtvPCxBRtf8ONeYLcxyfqprb9Oo4-kw5TbkHkHQgA3AsosaeCiCHlXOd7= cq_UfLiaWIRjSVTSSXeKPW8$ for graphic product...

ATTN...WFO...LCH...LIX...SHV...

ATTN...RFC...FWR...ORN...NWC...

LAT...LON 31389302 31089232 30719144 30359070 30079019=20
29668970 29168963 28929013 29089129 29709306=20
30059433 30909437 31289399=20

=3D =3D =3D
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AWUS01 KWNH 102050
FFGMPD
TNZ000-MSZ000-ARZ000-110100-

Mesoscale Precipitation Discussion 0167
NWS Weather Prediction Center College Park MD
449 PM EDT Sun May 10 2026

Areas affected...central/northern AR into southwestern TN/northern
MS

Concerning...Heavy rainfall...Flash flooding possible

Valid 102048Z - 110100Z

Summary...Scattered thunderstorms, some of which will be slow
moving, are expected to continue to pose a widely scattered flash
flood threat across portions of the Lower MS Valley over the next
3-4 hours. Hourly rainfall of 2-3 inches could allow for a few
isolated 3-5 inch totals within a 2-3 hour window.

Discussion...2030Z radar imagery over AR showed an expanding
coverage of thunderstorms with a few of the cells exhibiting
backbuilding toward the west and slow overall movement, resulting
in MRMS-derived hourly rainfall between 2-3 inches. A few of the
cells were forming along a number of boundaries, including a
diffuse stationary front that extended from south-central AR into
north-central MS, marked by dewpoints in the mid-60s to lower 70s
south of the boundary with dewpoints falling off into the 50s from
TN into northern MS, north of the front. Meanwhile a stronger cold
front to the north and rain-cooled air from eastern OK were
marking the northern and western edge of the short term heavy rain
threat. Lift across the region was being enhanced by placement
within the right-entrance region of an upper jet max extending
from MO into southern IL.

SPC mesoanalysis data from 20Z showed MLCAPE of 500 to just over
1500 J/kg along with PWs of 1.3 to 1.6 inches. Sufficient speed
sheer was present for some organization to cells but their
residence time over any given location appears to be limited to
approximately 1-2 hours given undercutting of rain-cooled air at
the surface. The threat should end from NW to SE with time, but
this means locations near and just east of the MS River could see
slow cell movement and possible flash flooding extending beyond
00Z. Given the observed rates so far, high rain rates could lead
to a couple of isolated to widely scattered locations picking up 3
to 5 inches of rain over the next few hours, supporting a
short-fused flash flood threat.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4XY2s_KzLP8N_fZaXXeM7LRui2aPxS8vQkKhPihvBv54c60VuieKyI4IYQ0bdeuJX0DW= 700y-61tvcIiATgOLgb4hZI$ for graphic product...

ATTN...WFO...JAN...LZK...MEG...

ATTN...RFC...ALR...ORN...TUA...NWC...

LAT...LON 35919340 35899243 35659011 35178917 34378872=20
33498890 32928924 32938999 33159121 33499225=20
33849293 34189327 35119331=20

=3D =3D =3D
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AWUS01 KWNH 102323
FFGMPD
TXZ000-110500-

Mesoscale Precipitation Discussion 0168
NWS Weather Prediction Center College Park MD
722 PM EDT Sun May 10 2026

Areas affected...Edwards Plateau into eastern TX

Concerning...Heavy rainfall...Flash flooding possible

Valid 102321Z - 110500Z

SUMMARY...Isolated to scattered instances of flash flooding will
be possible across portions of central to eastern TX through 05Z
(12 AM CDT). Slow moving and/or merging of cells are expected to
produce hourly rainfall of 2-3 inches and a few locations with
storm total rainfall of 3 to 5+ inches.

DISCUSSION...Radar imagery through 23Z over TX and LA showed
thunderstorms becoming more numerous over southeastern TX into
southwestern LA, along a sea breeze enhanced convergence axis
(trough axis) at the surface, which extended westward from the
southern TX/LA border toward I-35 just north of AUS. Farther north
and west, scattered strong to severe thunderstorms were ongoing
ahead of a southward sinking cold front which extended
southwestward from northern TX into the Big Bend region and along
an outflow boundary that preceded the cold front, extending
west-east from near Coleman to Nacogdoches. SPC mesoanalysis data
showed the environment across central TX was quite unstable with
MLCAPE of 1500 to 3000+ J/kg and PWS that ranged from about 1.3 to
1.6 inches.

A general southeastward progression is expected regarding the
ongoing thunderstorms ahead of the cold front and preceding
outflow boundary as these boundaries continue to sink south, ahead
of an approaching shortwave trough axis from KS to eastern NM.
Meanwhile, thunderstorms are likely to increase in coverage from
southeastern into central TX, along the trough axis as low level
flow increases beyond 00Z. Some of these storms could be slow
moving with backbuilding characteristics due to the weak 0-6 km
mean layer wind over the region (<10 kt) and increasing 0-1 km
winds from the southeast across the Coastal Plain of TX. These
slow moving storms are expected to eventually merge with an
approaching cluster of thunderstorms with the advancing cold
front/outflow from the northwest. Peak hourly rainfall of 2-3
inches (locally higher) is likely with slow moving and merging of
cells, with potential for a few locations to pick up 3 to 5+
inches of total rainfall through 05Z.

Flash flood guidance varies across the region with high 3-hr
values of 3 to 5+ inches in 3 hours to the east of I-35; lower FFG
values for the Edwards Plateau. Therefore, despite the potential
for high rainfall values, the flash flood threat will be most
focused across urban locations and otherwise sensitive terrain
west of I-35.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6bNzcVc7Z3vjDySNFQrektLOtDSC7LddZSpJrHTlW1yoFAg37i8IYCMmPVEDnjAXDu6G= 3ntMeWc8YPeONwcNu2VqSko$ for graphic product...

ATTN...WFO...CRP...EWX...FWD...HGX...LCH...SHV...SJT...

ATTN...RFC...FWR...NWC...

LAT...LON 32109793 31899619 31479428 30239416 29919577=20
29539695 29049824 28349952 28700060 30930069=20
31869979=20

=3D =3D =3D
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AWUS01 KWNH 110515
FFGMPD
LAZ000-TXZ000-110813-

Mesoscale Precipitation Discussion 0169
NWS Weather Prediction Center College Park MD
114 AM EDT Mon May 11 2026

Areas affected...central/east Texas into far western Louisiana

Concerning...Heavy rainfall...Flash flooding possible

Valid 110513Z - 110813Z

Summary...Flash flood potential will continue for at least 2-3
more hours (through 08Z/3a central).

Discussion...Flash flood potential continues especially in east
Texas. A slow-moving mesoscale convective complex has matured,
with individual cells exhibiting speeds of around 5-15 knots amid
a strengthening mid-level circulation over central Texas.=20
Meanwhile, remnant outflow boundaries/surface troughing downstream
of the complex has fostered areas of scattered convective
development especially near College Station eastward to near
Leesville, LA/Fort Johnson. The slow movement of cells amid an
abundantly moist environment (1.5 inch PW values) and lingering
surface-based instability has supported several areas of 2+
inch/hr rain rates at times. These rain rates have approached FFG
thresholds on an isolated basis along with a few instances of
flash flooding reported west of College Station.

Ongoing trends suggest flash flood potential should continue for
at least another 2-3 hours. The downstream airmass supporting
convection remains moderately unstable (around 2000 J/kg MLCAPE),
with convection continuing to refire both with the leading edge of
the MCS and along the aforementioned east-west oriented boundaries
across the region. FFG thresholds get generally higher with
eastward extent however -- suggesting that any continued flash
flood threat should remain concentrated near any low spots and/or
urban areas that can experience 2+ inch/hr rain rates or have
those rates extend for a period longer than 1 hour. The latter is
possible on an isolated basis given the slow movement of cells.=20
Over time, convection should approach the southeast Texas coast
and move toward the northwestern Gulf, reducing flash flood
potential thereafter.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-kcZPk_hmksR4wRcqDDmW0zeAK6VJNmkzYGSX7vtSCjh8LjH3KMlrdrC1wXjdsNBXz72= uoPGKIDYJLtTMfv1L_7W2fI$ for graphic product...

ATTN...WFO...EWX...FWD...HGX...LCH...SHV...

ATTN...RFC...FWR...ORN...NWC...

LAT...LON 31559469 31309277 30249237 29639336 29349544=20
29539691 31049679=20

=3D =3D =3D
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AWUS01 KWNH 112043
FFGMPD
ALZ000-MSZ000-LAZ000-120215-

Mesoscale Precipitation Discussion 0170
NWS Weather Prediction Center College Park MD
443 PM EDT Mon May 11 2026

Areas affected...southern LA into southern MS/southwestern AL

Concerning...Heavy rainfall...Flash flooding possible

Valid 112041Z - 120215Z

Summary...Scattered thunderstorms will pose a flash flood threat
from southwestern LA into southern MS and far southwestern LA.
Hourly rainfall of 2 to 3+ inches and localized totals of 3 to 5+
inches are expected.

Discussion...Radar imagery across southern LA at 2030Z showed slow
moving thunderstorms stretching from near a surface low (southeast
of LCH) into southern MS/AL (just south of a HZR to PIB line),
near a slow moving cold front. Water vapor imagery showed a well
defined shortwave advancing east from eastern TX, providing ascent
across southern LA. 20Z SPC mesoanalysis data showed the region
contained 500 to 1500 J/kg MLCAPE and anomalously high PWs at 1.6
to 2.0 inches (1-2 standard deviations above the mean for
mid-May).

Thunderstorms are likely to continue expanding along the front and
near the surface low with a general eastward translation to
convection with time. In addition, thinning cloud cover in the
vicinity and south of Lake Pontchartrain may allow for locally
increased instability and potential for thunderstorms into the
early evening. Effective bulk shear ranged from <20 to >40 kt
across the region and coupled with the modest instability in
place, cell organization should be mixed, but widespread
organization is not expected.

Two big factors for flash flooding through the remainder of the
afternoon into the evening hours will be slow cell motions (0-6 km
mean layer winds are <10 kt) and wet antecedent conditions. Given
large portions of the central Gulf Coast to locations 100 miles
inland have received 300 to 600 percent of their average rainfall
over the past week, increased soil moisture will be more prone to
runoff and flash flooding.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9e_GRW-GZUafZx1F4F7F4oKFue8kwmv3mEvMkrNnJN7cZEq0V88hNTtunm6eQdxjTJaR= -yySiDSE8VPsMQMKsZv0kfo$ for graphic product...

ATTN...WFO...JAN...LCH...LIX...MOB...

ATTN...RFC...ALR...ORN...NWC...

LAT...LON 31648790 31258761 30838770 30338797 29668956=20
29549070 29459270 29729335 30229355 30719323=20
31029203 31309087 31528911=20

=3D =3D =3D
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AWUS01 KWNH 120228
FFGMPD
FLZ000-GAZ000-ALZ000-MSZ000-LAZ000-120730-

Mesoscale Precipitation Discussion 0171
NWS Weather Prediction Center College Park MD
1027 PM EDT Mon May 11 2026

Areas affected...central/east-central Gulf Coast

Concerning...Heavy rainfall...Flash flooding possible

Valid 120226Z - 120730Z

Summary...Heavy rain with embedded thunderstorms are expected
along portions of the central to east-central Gulf Coast through
07Z. Isolated flash flooding will remain possible due to hourly
rainfall of 2 to 3+ inches and localized totals of 3 to 5+ inches.

Discussion...Heavy rain remained in a few locations over
southeastern LA as of 02Z with a small cluster of largely
warm-topped showers/thunderstorms southwest of Lake Pontchartrain
with MRMS-derived peak hourly rainfall between 2 and 3 inches. The
00Z LIX sounding showed a moist environment with at PW of 1.9
inches and only 5 kt of 0-6 km mean layer flow, supportive of slow
cell movement. Instability was weak, however, with only 280 J/kg
MLCAPE on the LIX sounding. Over the past hour, there has been
some eastward development of localized heavy rain cores through
southern MS/AL and the western FL Panhandle. These appear to be
focused along a low level axis of convergence, just above the
surface, represented in 925 mb VAD wind plots, extending from near
Lake Pontchartrain into the FL Panhandle. Aloft, a potent mid to
upper-level shortwave was noted on water vapor imagery just east
of the Sabine River. Divergent flow aloft was focused just ahead
of the shortwave and associated jet axis across southeastern LA
into southern MS, aiding lift over the region.

As the shortwave continues to move east tonight, ascent will
translate downstream along the Gulf Coast, with embedded areas of
heavy rain likely following suit. Given the moist environment (PWs
of 1.6 to 1.9 inches), with warm-layer depths of 3500-4000 m,
efficient rainfall will be likely with hourly rainfall of 2 to 3+
inches at times and possibly 3 to 5 inches within a 2-3 hour
period. While weak instability (less than 1000 J/kg) will limit
the coverage of heavy rain, small pockets of flash flood potential
will remain a possibility over at least the next 3-5 hours.
Another consideration is the higher than average rainfall over the
past 1-2 weeks across a good portion of the region which may leave
locations more prone to runoff compared to average.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_tHGKIWrR5_z1HT4s_Ux8cvKXHhM1-bQm_cW0yKZ84gAO0sPlU85fQeEjNShPtHvgztW= T_aPohfp7eMG3kr7FRmYRu8$ for graphic product...

ATTN...WFO...JAN...LIX...MOB...TAE...

ATTN...RFC...ALR...ORN...NWC...

LAT...LON 31538685 31348491 30798405 30038420 29538512=20
29508610 29818860 29668986 29589045 29829090=20
30359093 30979028 31238915=20

=3D =3D =3D
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AWUS01 KWNH 130317
FFGMPD
FLZ000-GAZ000-130715-

Mesoscale Precipitation Discussion 0172
NWS Weather Prediction Center College Park MD
1116 PM EDT Tue May 12 2026

Areas affected...portions of southern Georgia

Concerning...Heavy rainfall...Flash flooding possible

Valid 130315Z - 130715Z

Summary...A nearly stationary band of convection over
south-central Georgia was producing 1-2.5 inch/hr rain rates just
northwest of Valdosta. These rates could persist for another
couple hours. Flash flooding is possible in the affected areas.

Discussion...A nearly stationary band of convection has exhibited
very slow and erratic movement over areas from near Thomasville to
near Adel. The storms were situated directly beneath an upper low
over the area, which was likely combining with weak, isentropic
ascent to support persistent, shallow updrafts despite marginal
instability (~500 J/kg MUCAPE per SPC Mesoanalyses). The overall
scenario for flash flooding was not evolving quickly, and with
peak rain rates exceeding local FFG and prompting modest MRMS
Flash responses, it is likely that local impacts from excessive
runoff are underway in at least a couple of spots.

High-res guidance suggests that storms will weaken through 06Z,
although their current handling of the scenario lends some
uncertainty, and observations suggest that the ongoing threat will
persist beyond 05Z/1a eastern. Additional local totals of 3
inches cannot be ruled out. Conditions will be monitored for
additional flash flood potential beyond 07Z.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_JLcn6ufdLbr1LKWHMaGV_GlcjUQjllUzR4txnx7YPCTIBOqgqz4DrpREUNqS1s9SB9i= AAZX3tszgbSnyYnhw1xaKOM$ for graphic product...

ATTN...WFO...JAX...TAE...

ATTN...RFC...ALR...NWC...

LAT...LON 31508294 31318256 30888274 30568396 30898445=20
31298384=20

=3D =3D =3D
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AWUS01 KWNH 130323
FFGMPD
FLZ000-GAZ000-130715-

Mesoscale Precipitation Discussion 0172
NWS Weather Prediction Center College Park MD
1122 PM EDT Tue May 12 2026

Areas affected...portions of southern Georgia

Concerning...Heavy rainfall...Flash flooding possible

Valid 130315Z - 130715Z

Summary...A nearly stationary band of convection over
south-central Georgia was producing 1-2.5 inch/hr rain rates just
northwest of Valdosta. These rates could persist for another
couple hours. Flash flooding is possible in the affected areas.

Discussion...A nearly stationary band of convection has exhibited
very slow and erratic movement over areas from near Thomasville to
near Adel. The storms were situated directly beneath an upper low
over the area, which was likely combining with weak, isentropic
ascent to support persistent, shallow updrafts despite marginal
instability (~500 J/kg MUCAPE per SPC Mesoanalyses). The overall
scenario for flash flooding was not evolving quickly, and with
peak rain rates exceeding local FFG and prompting modest MRMS
Flash responses, it is likely that local impacts from excessive
runoff are underway in at least a couple of spots.

High-res guidance suggests that storms will weaken eventually,
although their current handling of the scenario lends some
uncertainty, and observations suggest that the ongoing threat will
persist beyond 05Z/1a eastern. Additional local totals of 3
inches cannot be ruled out. Conditions will be monitored for
additional flash flood potential beyond 07Z.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6OEC3aqxpJPnrs5VyIuUSgGYeHA44qztazW8scmJQfFPgwotsYc9lVlw8IW_qZ79RjBJ= mhdCFGRJ8j9zGJMO176dvOw$ for graphic product...

ATTN...WFO...JAX...TAE...

ATTN...RFC...ALR...NWC...

LAT...LON 31508294 31318256 30888274 30568396 30898445=20
31298384=20

=3D =3D =3D
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AWUS01 KWNH 161951
FFGMPD
KYZ000-INZ000-ILZ000-170130-

Mesoscale Precipitation Discussion 0173
NWS Weather Prediction Center College Park MD
350 PM EDT Sat May 16 2026

Areas affected...Southern Illinois...Southern Indiana ...adjacent
Northwest Kentucky...

Concerning...Heavy rainfall...Flash flooding possible

Valid 161950Z - 170130Z

SUMMARY...Favorable environment for subtle heavy rainfall style
event or two given proximity to mid-level shortwave center passing
to southeast.

DISCUSSION...19z surface analysis denotes a weak surface wave just
southeast of St. Louis, MO sitting along a stationary thermal
boundary, reinforced by early morning rainfall/outflow. CIRA LPW
suite (oblique polar pass) shows a small pool of enhanced boundary
level to 500mb moisture along combined with upper 60s and low 70s
Tds through S IL/S IND, bringing a small pocket of overall totals
over 1.75" within a favorable southwesterly to west-southwesterly
WAA 925-850mb flow regime increasing moisture flux convergence
along it. While cloud cover has been generally dense this morning
into early afternoon, some clearing and broken insolation has seen
temps into the low 80s, particularly downstream into NW KY/S IND,
resulting in a narrow west to east axis of 2000 J/kg MLCAPE that
is becoming increasingly uncapped.

GOES-E WV suite along with visible loop, shows a small mid-level
shortwave twist to the cloud pattern over NW KY that is expected
to continue a east-northeast progression further providing larger
scale ascent, especially downstream. However, aloft, RAP analysis
denotes a strong divergence signal at the far right entrance to
the jet streak over the Great Lakes across central IL, along the
northwest periphery of the shortwave. The combination of all
factors is supporting initial break out of deeper updrafts (rapid
cooling and expansion of these clusters/cells shows potential
instability of the broader area). So low level WAA/convergence
should help feed the updrafts with slow eastward movement given
15-20kts of deep mean steering flow, but overall inflow from the
west-southwest results in favorable propagation vectors for
back-building and or slowing of the forward progression of
clusters that due develop mainly because of the proximity on the
NW side of the mid-level shortwave. As a result there is good
potential for increased residency of stronger/broader moist
updrafts capable of 1.5-2"/hr rates. Localized totals of 2.5-3"
are possible.

Stronger cells with greater coverage are expected downstream/east
of the shortwave but should be forward propagating quicker;
however, these rates/quick totals of up to 1" could set the stage
for the slower moving upstream allowing repeating. While the
overall Midwest has been dry, NASA SPoRT 0-40cm soil moisture
values of 50-65% across the area of concern, which is much higher
than surrounding areas (not including this morning's rainfall
tracks). So with FFG values of 1.5-2"/hr and 2-2.5"/3hrs, and
proximity to flash flood prone cities like Evansville/Louisville
there is sufficient potential for a localized incident or two of
possible flash flooding through late afternoon/evening across the
area of concern.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!497FomLp5UQm8ELrJMqWCK5KLr8wHwkWmjbAMOrKtiJSJGuJBZPcDRxdQwKFWbxiyYxg= P9lrIiE-5I43OJ3RgHbNsxE$ for graphic product...

ATTN...WFO...ILN...ILX...IND...LMK...LSX...PAH...

ATTN...RFC...MSR...ORN...TIR...NWC...

LAT...LON 39598784 39508661 39328518 38868469 38278474=20
37838551 37738654 37658748 37658849 37748931=20
38118978 38618992 39198967 39518904=20

=3D =3D =3D
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AWUS01 KWNH 162121
FFGMPD
MOZ000-IAZ000-KSZ000-NEZ000-170315-

Mesoscale Precipitation Discussion 0174
NWS Weather Prediction Center College Park MD
520 PM EDT Sat May 16 2026

Areas affected...Northern MO...Southwest IA...Ext. Southeast
NEB...

Concerning...Heavy rainfall...Flash flooding possible

Valid 162120Z - 170315Z

SUMMARY...Slow moving, back-building thunderstorms with 1.75-2"/hr
rates will support mergers and repeating through the evening
hours. Localized 3-4" totals are probable with isolated 5"+
possible. Flash flooding is considered possible, given recent dry
conditions may help mitigate moderate rainfall totals.

DISCUSSION...21z surface analysis depicts a weak surface wave near
Nebraska City, generally at the western extent of the deeper
moisture plume across the Central U.S. Deep southwesterly flow
aloft is providing broad scale ascent and lowering surface
pressures in the lee of the Rockies and driving a broad strong
southerly LLJ across the Plains and Ozark Plateau. This
moisture/higher theta-E air is generally mid-80s over upper
60s/low 70s Tds, supporting total PWats near 1.5" and with
southwesterly flow aloft, resulting in steepening lapse rates,
supportive of 3000-3500 MLCAPE across E KS into NW MO.=20=20

The surface low resides at the apex of a broader surface SW to NE
trough with the frontal boundary extending along the KS/NEB
boarder before angling northeast across south central IA into S
WI. A more important outflow boundary from last night/this
morning's convection has effectively become a deeper thermal
boundary/warm front from near CSQ in IA dropping south across
north-central MO toward KCOU before turning E across S IL. As
such, the southerly surface to 700mb southerly flow is ascending
isentropically across is boundary resulting in the first bands of
deeper convection across north-central MO. Overall, vigor remains
a bit limited but will further aid in steepening the
boundary/isentropes over the next few hours, increasing deep layer
moisture convergence. As the LLJ strengthens, flux convergence
will help to broaden updrafts and rainfall efficiency as the
overall moisture pool increases to 1.75" TPW toward 23z. Overall
coverage and broadening updrafts will allow for cells to increase
to 1.75"/hr rates with occasional 2-2.25" occurring and localized
2.5" for eventual short-term mergers.=20=20

The concern toward and after 00z, will be the broadening of the
500-1000mb thickness lines, reducing forward propagation and
bending steering flow a bit more south of due east further
increasing convergence, though this will be concurrent with
strengthening upstream inflow turning propagation vectors
southwest with time, allowing for higher potential of an
individual cell's residency and/or repeating tracks. Eventually,
back-building toward southeast NEB. A broad swath of 2-5" is
becoming more probable across this area with 18z HREF probability
of 70-90% of 3"/6hrs along/near the intersection of the
fronts/outflow along the IA/MO line. This is likely to shift
(more likely south and west given trends); the 'good news' is the
area has very high FFG values (2.5"/hr; 3-4"/3hrs) due to
prolonged dry spring with 0-40cm Soil Moisture around 25-30%,
though areas nearer the Missouri River and portions of SW IA are a
bit more moist and have lower FFG values. Still, the overall
rainfall and rates are still possible to induce widely scattered
to scattered incidents of flash flooding through 03z. Please note:
further upstream development over the Higher Central Plains is
likely to roll through later into the overnight period (after
03z), so at best, this round will only wet the upper soil column
for those cells later too, a subsequent MPD may be required.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9VcXlr9_PjGyMcyHRwzaSKTnfhvLyeyW1M46Y6h_NlSaMkIhxNXPTJ7sbEeIN-kF0ZwC= aRfQxuA7aCSzyGbrlskHsqw$ for graphic product...

ATTN...WFO...DMX...EAX...LSX...OAX...

ATTN...RFC...KRF...MSR...NWC...

LAT...LON 41479517 41439361 40519263 39679173 38959238=20
39259379 40199563 40589631 41069611=20

=3D =3D =3D
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AWUS01 KWNH 170035
FFGMPD
KSZ000-NEZ000-170600-

Mesoscale Precipitation Discussion 0175
NWS Weather Prediction Center College Park MD
834 PM EDT Sat May 16 2026

Areas affected...Southern Nebraska...Portions of Northwest
Kansas...

Concerning...Heavy rainfall...Flash flooding possible

Valid 170035Z - 170600Z

SUMMARY...Slow moving super-cells becoming localized heavy rain
producers, before main upstream cluster/MCS puts final additional
heavy burst to exceed very dry ground conditions for a widely
scattered incident or two of localized possible flash flooding.

DISCUSSION...00z surface and RAP boundary layer analysis depict a
very tight moisture stream along and south of well defined
stationary front that extends from active convection in SE IA and
through southern NEB from south of Lincoln to Hastings to Holdrege
before angling toward expanding progressive cluster, developing
MCS coming out of NW KS. Strong surface pressure falls upstream
has accelerated near boundary layer easterly flow increasing low
level moisture profile as noted in CIRA LPW even through the
700-500mb layer, with the 1.5" total PWat starting to nose as far
west as south-central NEB. Surface southerly flow backing with
height has provided solid low level moisture convergence given Tds
rising into the low 60s, with some trapped moisture on the
north-side of the boundary into the mid-60s as far east as Grande
Island, NEB; reducing sub-cloud evaporation. As such, recent
trends in KDP analysis show increasing degrees/KM suggesting
additional higher rainfall rates with reducing near or sub-zero
values for 'large hail' signatures strongly suggesting increasing
rainfall efficiency over the last hour or so.=20

Overall RADAR coverage of convective cores has increased as well
given numerous left splitting super-cell structures; but with the
updraft rotation, forward propagation has slowed mainly for the
right movers to increase residency . While rain-rates are still
likely inflated due to hail contamination, hourly rates of 1.5-2"
are becoming more probable given the increasing moisture flux
convergence due to isallabaric effects. Localized totals of
1.5-2.5" are becoming increasingly possible but narrowly focused
along and just north of the stationary front. However, the strong
drought in the region is resulted in very dry conditions and
allowing for a solid uptake of those totals, but the rates may
still be a tad to great locally, resulting in some spots of
localized flash flooding potential. This will only be exacerbated
as the upstream MCS cluster sweeps up/merges with the remaining
super-cells through the early overnight period across
south-central NEB, with a sub-hourly burst of .75-1" in 15 minutes
per recent HRRR output resulting in spot or two of 2-3" values
which is in the range of 1 to 3hr FFG exceedance and localized
flash flooding is therefore considered possible, more so eastward
through the MPD area of concern.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4XlChmG_LE-3luG20gQb4qjwQH7bwTkdmvJOtRUNDq3vcXB-1_eD2fJKOb0yKc6dWZMA= vAczv6JUWFHWDSMDeuaQPHE$ for graphic product...

ATTN...WFO...GID...GLD...LBF...OAX...

ATTN...RFC...KRF...NWC...

LAT...LON 41779746 41589658 41009601 40599586 40109621=20
40059743 39919950 39590085 40280134 40880070=20
41239990 41649855=20

=3D =3D =3D
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AWUS01 KWNH 170331
FFGMPD
ILZ000-MOZ000-IAZ000-KSZ000-NEZ000-170720-

Mesoscale Precipitation Discussion 0176
NWS Weather Prediction Center College Park MD
1129 PM EDT Sat May 16 2026

Areas affected...middle MO RIver to middle MS River Valley

Concerning...Heavy rainfall...Flash flooding likely

Valid 170328Z - 170720Z

Summary...Areas of flash flooding will remain likely across
portions of southeastern NE, northeastern KS into southwestern IA
and northwestern MO over the next couple of hours. Locations
farther east may also experience flash flooding. Peak hourly
rainfall of 2 to 3+ inches can be expected.

Discussion...An axis of thunderstorms was oriented roughly west to
east at 03Z, extending from southeastern NE into northwestern and
northern MO, with a slow moving MCV in north-central MO along the
eastern flank of the MCS. A Flash Flood Emergency was recently
issued for Grundy County, including the city of Trenton where ~6
to 8 inches of rain has fallen with embedded hourly rainfall over
3 inches (and 2.5 inches in 30 minutes) at times. Back to the
west, thunderstorm coverage was increasing over the southeastern
quadrant of NE, in advance of a forward propagating line segment
advancing along the central NE/KS border.

The activity was largely elevated atop a remnant outflow boundary
which extended ESE from southeastern NE, just south of STJ into
north-central MO. MUCAPE values were 2000-3000 J/kg via 03Z SPC
mesoanalysis data and 850 mb VAD wind data at KTWX showed
strengthening flow between 00-03Z (30 to 55 kt) with further
strengthening to near 60 kt possible by 06Z. Aloft, flow was
fairly diffluent/divergent to the south of an 80-100 kt upper jet
max north of the region. Sufficient shear and instability will
sustain a mixture of supercells and multicells with a combination
of slow cell motions, mergers and training leading to high hourly
rainfall, locally in excess of 3 inches possible over the next 2-4
hours.

There are signs in the recent hires guidance that the pattern will
be disrupted toward 06-07Z, in advance of the forward propagating
line segment over the NE/KS border as increasing southerly flow
and forcing shifts northward of the present axis. However, prior
to that time, another 3-4 hours of locally heavy rain with areas
of flash flooding will remain likely with an additional 3-5 inches
of rain possible through 07Z, with a focus in and around the MO
River Valley.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!760uQl1ohFv2KU1K6qPWh_0aJfvHwirl-l3LZ2hyyMw3Tv0DIsmmzLmmfVFlqTOOG4jb= 94fPrgL7u0SXf38ulDn2Wj4$ for graphic product...

ATTN...WFO...DMX...DVN...EAX...GID...LSX...OAX...TOP...

ATTN...RFC...KRF...MSR...NWC...

LAT...LON 41519233 41169114 39849151 39449302 39519515=20
39959703 40439746 40809729 41219669 41429459=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
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AWUS01 KWNH 170338
FFGMPD
ILZ000-MOZ000-IAZ000-KSZ000-NEZ000-170720-

Mesoscale Precipitation Discussion 0176...Corrected
NWS Weather Prediction Center College Park MD
1137 PM EDT Sat May 16 2026

Corrected for adjustment to capitalization in areas affected

Areas affected...middle MO River to middle MS River Valley

Concerning...Heavy rainfall...Flash flooding likely

Valid 170328Z - 170720Z

Summary...Areas of flash flooding will remain likely across
portions of southeastern NE, northeastern KS into southwestern IA
and northwestern MO over the next couple of hours. Locations
farther east may also experience flash flooding. Peak hourly
rainfall of 2 to 3+ inches can be expected.

Discussion...An axis of thunderstorms was oriented roughly west to
east at 03Z, extending from southeastern NE into northwestern and
northern MO, with a slow moving MCV in north-central MO along the
eastern flank of the MCS. A Flash Flood Emergency was recently
issued for Grundy County, including the city of Trenton where ~6
to 8 inches of rain has fallen with embedded hourly rainfall over
3 inches (and 2.5 inches in 30 minutes) at times. Back to the
west, thunderstorm coverage was increasing over the southeastern
quadrant of NE, in advance of a forward propagating line segment
advancing along the central NE/KS border.

The activity was largely elevated atop a remnant outflow boundary
which extended ESE from southeastern NE, just south of STJ into
north-central MO. MUCAPE values were 2000-3000 J/kg via 03Z SPC
mesoanalysis data and 850 mb VAD wind data at KTWX showed
strengthening flow between 00-03Z (30 to 55 kt) with further
strengthening to near 60 kt possible by 06Z. Aloft, flow was
fairly diffluent/divergent to the south of an 80-100 kt upper jet
max north of the region. Sufficient shear and instability will
sustain a mixture of supercells and multicells with a combination
of slow cell motions, mergers and training leading to high hourly
rainfall, locally in excess of 3 inches possible over the next 2-4
hours.

There are signs in the recent hires guidance that the pattern will
be disrupted toward 06-07Z, in advance of the forward propagating
line segment over the NE/KS border as increasing southerly flow
and forcing shifts northward of the present axis. However, prior
to that time, another 3-4 hours of locally heavy rain with areas
of flash flooding will remain likely with an additional 3-5 inches
of rain possible through 07Z, with a focus in and around the MO
River Valley.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6lp2bl8r2tBWDmKe5Xs-dZIdDzoRrojlanQquKmErPU2Z8lJDHRJW0g96IdmGe4yQwmJ= 1N4HSrlVSjiky8mbFPXahyE$ for graphic product...

ATTN...WFO...DMX...DVN...EAX...GID...LSX...OAX...TOP...

ATTN...RFC...KRF...MSR...NWC...

LAT...LON 41519233 41169114 39849151 39449302 39519515=20
39959703 40439746 40809729 41219669 41429459=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
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AWUS01 KWNH 170747
FFGMPD
WIZ000-ILZ000-MOZ000-IAZ000-NEZ000-171300-

Mesoscale Precipitation Discussion 0177
NWS Weather Prediction Center College Park MD
346 AM EDT Sun May 17 2026

Areas affected...western IA/MO border into IA and southwestern
WI/northwestern IL

Concerning...Heavy rainfall...Flash flooding possible

Valid 170745Z - 171300Z

SUMMARY...Localized flash flooding will remain a possibility
through 13Z (8 AM CDT) from the western IA/MO border into IA and
the MS River near the WI/IL border. Hourly rainfall of 1-2 inches
and localized peak rainfall of 2-4 inches can be expected.

DISCUSSION...Radar imagery across the middle MO River Valley
showed a convectively induced vorticity max along the southern
NE/IA border at 0715Z associated with an eastward bowing line
segment crossing into southwestern IA and northwestern MO. Areas
of stratiform rain preceded and followed the bowing segment (which
has shown signs of weakening over the past 30 minutes), along with
a few stronger cells near the MO/IA border. However, trends in
MRMS-derived hourly rainfall showed a reduction in the coverage
and intensity of high rain rates since 05Z as convective
development just north of a remnant outflow boundary draped across
northern MO has reduced.

Short term forecasts from the RAP indicate the shortwave/vorticity
max along the southern NE/IA border will track northeastward over
the next 3-6 hours. Low level overrunning of the remnant
outflow/effective front in northern MO will continue as the
mid-level circulation advances toward the northeast beneath
diffluent and divergent flow in the upper levels. Elevated
instability of 500 to 1000+ J/kg was estimated over southern IA
via the 07Z SPC mesoanalysis but these values fall off quickly to
the north with only modest northward advancement of the elevated
instability pool through 13Z forecast. Over the next 3-6 hours,
there will continue to be the potential for short term training
with 1 to 2 inches of rain in an hour and localized potential for
2-4 inches through 13Z (8 AM CDT), located near the track of the
shortwave. While the expected potential for heavy rain over the
next few hours will be north of areas that experienced flooding
earlier tonight in northern MO, portions of IA have received 1 to
3 inches of rain over the past 48 hours which may contribute to
isolated runoff where overlap of additional heavy rain occurs.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4GSUKMFNjbMh4tO-hoxs6y7pFNqyNKqPmwEgSMHZiECgN2PqEkh6QnZ4Xi3mrGDOUgHH= BdM-up4CIAjmW8DM5mtEfF0$ for graphic product...

ATTN...WFO...ARX...DMX...DVN...EAX...LOT...MKX...OAX...

ATTN...RFC...KRF...MSR...NWC...

LAT...LON 43059094 42929044 42488989 41958968 41528997=20
41139078 40659201 40059360 40149525 40569575=20
41139579 42069401 42789210=20

=3D =3D =3D
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AWUS01 KWNH 171959
FFGMPD
MNZ000-IAZ000-NEZ000-SDZ000-180200-

Mesoscale Precipitation Discussion 0178
NWS Weather Prediction Center College Park MD
358 PM EDT Sun May 17 2026

Areas affected...Southeast SD...Eastern NEB...Western IA...Far
Southwest MN...

Concerning...Heavy rainfall...Flash flooding possible

Valid 172000Z - 180200Z

SUMMARY...Increasing available moisture to support higher rainfall
efficiency over the next few hours (up to 2"/hr). Progressive
nature may be a limiting factor, but cells will move into a bit
more prone to FF due to recent rains (esp. South).

DISCUSSION...19z surface analysis depicts the very dynamic
environment in place across the Plains this afternoon (given broad southwesterly flow aloft). The southern stream shortwave last
evening that has progressed into the Great Lakes helped to
reinforce a tight moisture gradient along the primary west to east
from from a weak wave in E IA back across central IA to a surface
wave near an strong cluster of thunderstorms with a history of
hail and forward progression. CIRA LPW and RAP analysis shows a
tight, enhanced moisture plume along and south of the boundary
generally denoted by agitated Cu field (NE NEB, into central IA)
opposed by north where transverse banding shows the greater
stabilized area that is a bit drier as well across far NW IA into
SW MN. Enhanced Tds in through 850mb along with slightly backed
flow for solid moisture flux transport toward the surface low
along/ahead of main cold front NE of O'Neil, Neb.

Solid low level directional convergence has aided maintenance of
the cluster with strong deep layer moisture convergence signals
denoting the flux. As the cluster reaches the deeper moisture
axis, expectation is both increased moisture loading to the
updrafts helping to broaden downdrafts as well as increase
rainfall efficiency. Rapid refresh guidance including the HRRR
and WoFS solutions denote this uptick in the next hour or so with
sub-hourly intense rates expected; with 15-minute HRRR totals over
1-1.25" while 5-minute rates in the WoFS over .5", as high as .75"
consistently across SE SDAK. Deep layer steering and cold frontal
push are likely to limit residency time but some eastward
development along the frontal/theta-E axis may break out
additional downstream cells to help with some repeating to reach
higher required totals to induce widely scattered incidents of
flash flooding (2-3" in 1-3hrs).=20=20

Further expansion of the convection toward the south along and
north of the stronger 995mb surface low along the NEB/KS will come
as embedded shortwave in the deeper southwesterly flow approaches
and upper-level diffluence increases into a developing north-south
jet streak placing much of the area of concern in favorable
divergence/outflow environment aloft in the right entrance of said
jet streak.

Hydrologically, much of the area remains in solid drought with
0-40cm ratios in the 20-30%, though scattered activity last night
did wet a few areas, especially south and east across E NEB and
through the Missouri River Valley. As noted, above the
progressive nature will likely limit the overall coverage of flash
flooding, but the shear intensity with some repeating and possible
intersection with those wetter upper soils, suggest widely
scattered flash flooding is possible this evening.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7dwM4qPIPaCm2epJ080lGFFhouAWdHzoYRclS2vg1hWL3BJR43tAvrJ_2Un0Mvx5YDMj= I4jqP5Dz8fofqhCJ4bf1SEg$ for graphic product...

ATTN...WFO...FSD...GID...OAX...

ATTN...RFC...KRF...MSR...NWC...

LAT...LON 44499698 44179587 43629534 42319568 41069591=20
40489702 40519934 40929935 41569836 42459794=20
42909829 43449867 44209800=20

=3D =3D =3D
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AWUS01 KWNH 180026
FFGMPD
MOZ000-IAZ000-KSZ000-NEZ000-180600-

Mesoscale Precipitation Discussion 0179
NWS Weather Prediction Center College Park MD
825 PM EDT Sun May 17 2026

Areas affected...Southeast NEB...Southwest IA...Northwest
MO...Central to Northeast KS...

Concerning...Heavy rainfall...Flash flooding possible

Valid 180025Z - 180600Z

SUMMARY...Training/Back-building cells at apex of dry slot will be
slow moving while higher moisture flux cells northward will track
through areas of recently saturated grounds with rates of 1.5"/hr
and spots of 2-3" totals, pose widely scattered incident or two of
flash flooding into early overnight period.

DISCUSSION...00z surface analysis depicts a very deep, but narrow
surface trough extending from a surface low in SE SD, southward to
a 993mb low just south of the central NEB/KS border at the nose of
an equally narrow but very dry slot; simultaneously, a strong
northern stream cold front is dropping southeastward from the low
resulting is a very strong surface to boundary layer flow with a
broad area of 20 to 30kts from the south slowly backing toward the
frontal zone. This results is a long axis of strong moisture flux
convergence, especially across SE NEB where Tds are in the high
60s, tipping toward the low 70s across the Missouri River into
IA/N MO. While the solid EML is well denoted in the CIRA LPW
850-700mb layer across much of this areas, return moisture
wrapped around the apex of the tight inverted trough, is pooled
along the approaching cold front. So while the steep lapse rates
are supporting MLCAPEs of 3000-4000 J/kd across E KS into SE NEB,
there is some entrainment of higher moisture and stronger
thunderstorms are starting to moisten the mid-layer profile and
overall rainfall efficiency is starting to increase and will do so
after sunset.

Coincident with the inverted trough is a tight 500-1000mb
thickness ridge the becomes a bit more divergent in isoheight
lines along and east of the trough axis. This supports reduced
forward propagation vectors, especially near the surface low and
south across central KS and with deep layer fairly unidirectional
flow from the SW, may allow for training/repeating across this
area while cells/clusters further north will start propagating east-northeastward at a more reasonable rate across E NEB into IA.
Evaporative loss will limit extreme rates, though the moisture
flux on the 30+kt inflow should support 1.5"/hr with an
occasionally uptick to 1.75"+, and may be slightly higher due to
ingest of smoke particulates from the prairie fires in Clark and
Meade counties.

Northward in SE NEB and along the IA/MO border, the heavy rainfall
last evening has brought FFG values into a range (1-1.5"/hr
<2"/3hrs) that may be locally exceeded with the clusters moving
east, suggesting a scattered incident or two of flash flooding
will be possible through early overnight period. Southward across
central KS, the unidirectional steering and upwind propagation may
allow for increased residency; so while this area's soil
conditions are very dry, the prolonged nature of rainfall with
localized spots of 2-4" may also result in localized FF. (Note: a
backyard observation near Dorrance, KS in E Russell county saw
just below 2" in the last hour). So all considering, a few spots
of flash flooding are considered possible across the MPD area of
concern through the overnight period.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5IInHaJaZZMwD3wa0TaLpebr92Hz9Aevw48MwlnPPZbxy9I-twDjBNXJPhPeOPj8Va6D= _El-L9tZjN8AHI9Tq73wSfU$ for graphic product...

ATTN...WFO...DDC...DMX...EAX...GID...ICT...OAX...TOP...

ATTN...RFC...KRF...MSR...TUA...NWC...

LAT...LON 42169490 42079412 41929340 41309302 40119334=20
39529611 38429803 38269948 38889946 39559824=20
40669796 41839753 42149622=20

=3D =3D =3D
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AWUS01 KWNH 180059
FFGMPD
WIZ000-MNZ000-IAZ000-180600-

Mesoscale Precipitation Discussion 0180
NWS Weather Prediction Center College Park MD
857 PM EDT Sun May 17 2026

Areas affected...Northern Iowa...Southern Minnesota...Parts of
Northwest Wisconsin...

Concerning...Heavy rainfall...Flash flooding possible

Valid 180100Z - 180600Z

SUMMARY...Increasing convective coverage and increasing moisture
flux into expanding convective clusters/small MCS features support
potential for repeating and spots of 2-4". Localized flash
flooding remains possible through the early overnight period.

DISCUSSION...GOES-E WV suite depict broad long-wave trough across
the Inter-mountain West with broad southwesterly flow downstream
across the Plains. At the apex an expanding convective complex
shows strong diffluent outflow pattern at the right entrance to
strengthening jet streak aloft providing broad scale ascent as
well as strengthening of a broad south-southwest LLJ. At the
surface the northern surface low/apex of a tight and deep inverted
surface trough is crossing out of SE SDAK into MN while drawing a
well defined warm front northward. CIRA LPW and RAP analysis
notes that core of western Gulf moisture is finally arriving
northward along and east of the advancing cold front that extends
from the surface low back across eastern NEB. The cluster in SW
MN has a very long history of severe and strong isallobaric
backing influence to maximize moisture flux pulled along and north
of the surface front, supporting intense but short-term rainfall
rates near 1.5-2"/hr mostly falling in 15-30 minutes. However,
given the stronger LLJ and isentropic ascent, downstream
convection is filling along and northeast where convergence is
maximized. Deep layer steering flow will allow for some repeating
of the cores to increase intense rainfall duration over 1-2 hours
allowing for localized totals to reach 2-3" values.=20

In addition, a second complex north of a secondary low across NE
NEB has seen a similar rapid cooling of the cirrus canopy with
numerous overshooting tops; deeper moisture pool has also
broadened the downdrafts width as the line matures into a larger
linear convective complex. While there is a general eastward
propagation, RADAR and satellite trends suggest there is also a
potential to repeat/track through similar areas of the northern
cluster across portions of S MN/N IA. Recent WoFS runs helps to
confirm this as mean and 90th percentile qpf suggest 2.5-5"
maximum swath is possible. This provides some confidence that
spots of 2-4" are becoming increasingly possible through the early
overnight period.=20

While NASA SPoRT 0-40cm soil moisture fields show drought is solid
with ratios running from 25% in NW IA to near 40% in south-central
MN toward the Twin Cities, the FFG values suggest 1hr rates of
1.5"/hr and less than 2.5"/3hr could result in flash flooding. If
that is the case, incidents of flash flooding are possible, but
given the overall drought conditions would be looking to smaller
localized incident or two where rates can reach closer to
1.75-2"/hr, where infiltration would be reduced from the shear
amount too fast. So given the overall pattern/trends, flash
flooding continues to be considered possible across the MPD area
of concern tonight.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6z3vCw4cBcd06sL2vpD6Yb8HccNxiHhZwedU4szunbouCqvjgG3v_xalByDNTvfqKBz2= SOYEEzqR1bhyP_Oz3PWcFVo$ for graphic product...

ATTN...WFO...ARX...DMX...FSD...MPX...

ATTN...RFC...KRF...MSR...NWC...

LAT...LON 45259218 44609139 43359219 42549394 42299574=20
42559638 43409586 44359487 45209331=20

=3D =3D =3D
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