ACUS11 KWNS 201815
SWOMCD
SPC MCD 201814=20
MSZ000-LAZ000-ARZ000-TXZ000-202015-
Mesoscale Discussion 0904
NWS Storm Prediction Center Norman OK
0114 PM CDT Tue May 20 2025
Areas affected...Eastern Texas into northern Louisiana
Concerning...Severe potential...Watch possible=20
Valid 201814Z - 202015Z
Probability of Watch Issuance...40 percent
SUMMARY...Thunderstorms developing along a cold front across eastern
Texas will likely pose a severe threat through late afternoon
downstream into northern Louisiana. Watch issuance is possible as
storm coverage becomes more clear in the next couple of hours.
DISCUSSION...A focused band of ascent is evident in recent GOES
imagery across east TX along an eastward moving cold front. KSHV and
KPOE have recently sampled a couple of deeper convective towers with
echo tops reaching up to 15-20 kft, suggesting that the probability
for deep convective initiation is steadily increasing. Further
heating of a very moist environment ahead of the front over the next
couple of hours will continue to erode inhibition and promote
thunderstorm development by around 19-21 UTC. While eastern TX/LA is
on the southern periphery of the stronger mid-level jet core to the
north across AR, 40-50 knot mid-level flow atop weak low-level winds
will still support elongated, nearly-straight hodographs. This thermodynamic/kinematic environment will support splitting
supercells with an attendant risk for severe gusts and large to very
large hail (possibly as high as 1.5 to 2.5 inches). Modest warm-air
advection across northern LA is currently supporting sufficient
low-level veering for around 100-150 m2/s2 0-1 km SRH, which could
support some tornado risk. However, flow within this layer is
expected to become more uni-directional through late afternoon, so
it is unclear if storms will intensify and migrate into the
favorably sheared environment before low-level helicity wanes.
Additionally, displacement from the stronger broad-scale ascent to
the north casts some uncertainty on convective coverage through the
afternoon. Watch issuance will likely be needed if a sufficiently
widespread threat becomes apparent.
..Moore/Hart.. 05/20/2025
...Please see
https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!8LZA1yJr_ftGtUrvK8bdgW-bcXnJqCYmrbNcikRrxzSlC9Blls9CmMUBmaN0rUqDLAMJb-0_d= F_uHQBUw02VZCFZzPg$ for graphic product...
ATTN...WFO...JAN...LCH...SHV...HGX...
LAT...LON 32179129 30899339 30619415 30579469 30759515 31119531
31339529 31539514 32619381 32879347 33019312 33049221
33019121 32739109 32459106 32179129=20
MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
=3D =3D =3D
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