• Heavy Rain - KY/TN - flooding possible

    From Mike Powell@618:250/6 to All on Sat May 30 08:02:10 2026
    AWUS01 KWNH 300924
    FFGMPD
    VAZ000-TNZ000-KYZ000-301500-

    Mesoscale Precipitation Discussion 0277
    NWS Weather Prediction Center College Park MD
    523 AM EDT Sat May 30 2026

    Areas affected...Southern Kentucky to Eastern Tennessee

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

    Valid 300922Z - 301500Z

    SUMMARY...Stationary front forcing a line of storms with erratic
    cell motions but ample moisture. Localized flash flooding possible.

    DISCUSSION...A stationary front denoted by a substantial moisture
    gradient is providing the forcing for a line of storms to form
    from southern Kentucky through eastern Tennessee. Weak, but
    nonetheless sufficient southwesterly flow into the front is
    allowing the moisture (PWATs as high as 1.9 inches in western
    Kentucky) to lift into the developing line of storms. Since they
    are both slow-moving and being reinforced by the moisture
    advection, expect the storms to persist for the next several hours
    until daytime heating works to disrupt the flow into the front, as
    well as introduce competing forcing from diurnal heating, cold
    pools, and in some areas, topography. This will result in a
    gradual diminishing of the storms associated with the front itself
    by late morning. While the front is stationary, since the overall
    flow into the front is stronger from the moist southwest side of
    the front, expect some northeastward drifting of the line of
    storms through the morning.

    HREF 6-hr FFG exceedance probabilities show as high as a 40-45
    percent in portions of south-central Kentucky, and another local
    maximum in eastern Tennessee of 25-30 percent through 15Z. Cell
    mergers northwest of Knoxville are already causing flash flooding,
    and expect with chaotic flow along the front that additional cell
    mergers will occur into southern Kentucky through the morning.
    What few pieces of high-resolution guidance are resolving the line
    of storms suggest that there will be rather rapid weakening of the
    storms by late morning for the aforementioned reasons, which will
    diminish the flash flooding threat.

    Wegman

    ATTN...WFO...JKL...LMK...MRX...OHX...PAH...

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

    LAT...LON 37878610 37738537 37548494 37418409 37198318
    36948243 36678187 36368205 36088271 35758336
    35608382 35858436 36238504 36498571 36498579
    36538581 36868663 37008689 37418701

    $$
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    * Origin: Project Scorpio TEST (618:250/6)