• Flood Threat VA/NC/SC/WV

    From Mike Powell@618:250/10 to All on Sun Oct 11 08:58:06 2026
    AWUS01 KWNH 110908
    FFGMPD
    VAZ000-NCZ000-WVZ000-SCZ000-111500-

    Mesoscale Precipitation Discussion 1477
    NWS Weather Prediction Center College Park MD
    507 AM EDT Sun Oct 11 2026

    Areas affected...Blue Ridge of Virginia, North Carolina and
    northern South Carolina...

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

    Valid 110910Z - 111500Z

    SUMMARY...Prolonged solid moisture flux into terrain with
    occasional localized south to north moving convective elements
    enhancing rates to 1"+/hr to add additional 1-2" with localized 3"
    spots along Blue Ridge. Flooding likely to continue and expand in
    coverage northward with time.

    DISCUSSION...Impressive GOES-E WV suite shows shortwave along
    eastern side has rotated north to recenter the deeper mid-level
    cyclone over central KY. This is lifting the center of Isaias
    northward into the Cumberland Plateau while also advancing the
    cold front out of GA into the Upstate of SC. Stationary front
    remains near the SC/NC border and is supporting active strong
    convection though the Gulf Stream. The combination is helping to
    maintain a solid low to mid-level gradient with cool conveyor belt
    still fluxing enhanced moisture north of the front westward into
    the terrain. CIRA LVT values are weakening slightly but remain
    above 150 kg/m/s across central VA given .75-.8" advected on
    30-40kts centered around 925mb. Aloft, the warm conveyor belt is
    broadening and shifting axis toward the Gulf Stream and 850-500
    LPW layers have seen a slow decrease; still 35-45kts of veering
    southwest to southerly flow is starting to intersect the terrain a
    bit more obliquely than earlier this morning and LVT values are
    more around 100-150 kg and narrowing toward the western branch of
    the WCB, just in advance of the cold front. As such, orographic
    ascent will support a third to half inch per hour, allowing for a
    broad area of 1-2" across the eastern slopes of the central
    Appalachians as the triple point lifts northeastward.

    Instability wedge remains about 500-1000 J/kg across SC, but is
    narrowing as well given limited northward surge of the effective
    warm front; convergence ahead of the front is still spurring
    convective development but it remains more scattered and less
    vigorous, continuous as before. Still given ample moisture, rates
    of 1-1.25"/hr remain possible across Upstate SC into the Foothills
    of W NC and far SW VA. Spots of additional 2-3" are possible but
    more likely to be isolated to widely scattered in nature. Given
    FFG values across far Upstate SC and W NC (less than .75" for all
    hours) are significantly compromised, even the remaining showers
    are likely to maintain flash flooding/broader riverine flooding
    this morning. As the TROWAL corridor shifts eastward intersecting
    into SW VA, FFG values have reduced to less than 1" for most hours
    as well and exceedance is probable. However, further north into
    central western VA, overall totals remain below 2" for the storm
    and additional 1-3" would bring some spots closer to FFG values
    but potential are less likely than further southwestward along the
    Blue Ridge Range.

    Gallina

    ATTN...WFO...GSP...LWX...RAH...RNK...

    ATTN...RFC...ALR...ORN...RHA...TIR...NWC...

    LAT...LON 39007830 38767815 38127848 37027946 35778017
    34768167 35028243 35458258 36228168 36778112
    37058078 37777996 38467915 38827883
    $$
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    * Origin: capitolcityonline.net * KY, USA (618:250/10)