Mesoscale Precipitation Discussion 0077
NWS Weather Prediction Center College Park MD
1244 AM EDT Mon Mar 17 2025

Areas affected...northeastern North Carolina into southeastern
Virginia

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

Valid 170444Z - 170900Z

Summary...Deep convection continues to develop across North
Carolina and stream north-northeastward into southeastern
Virginia.  1-2 inch/hr rain rates persist in the strongest
activity.  This regime should continue for at least another 3-4
hours, posing a continued risk of flash flooding.

Discussion...Convection has continued to refire along a surface
trough extending from just east of Richmond, VA to just east of
Raleigh, NC over the past couple hours.  This trough has allowed
for convective development to remain oriented generally parallel
to deep south-southwesterly flow aloft, allowing for substantial
training in a few locales.  Additionally, 1.5+ inch PW values and
500 J/kg SBCAPE supports efficient rainfall processes with the
ongoing storms.  Ascent from upstream mid-level troughing
continues to result in ascent/height falls over the trough as
well.  These factors support continued, SSW-NNE oriented training
bands of storms for the next 2-4 hours or so.

Over time, eastward translation of the surface trough and
mid-upper forcing will lead to an eventual end of heavy rainfall
potential - most likely after 08-09Z.  Between now and then,
concern exists that these training convective bands could
eventually make it in to populated, sensitive areas of
southeastern Virginia where lower FFGs (around 1 inch/hr) could
result in a few areas of flash flooding.  It is not out of the
question for rain rates to double those lower values (generally
extending from near Richmond southeastward through Virginia Beach)
and lead to locally significant impacts.

Cook

ATTN...WFO...AKQ...MHX...RAH...

ATTN...RFC...MARFC...SERFC...NWC...

LAT...LON   37587690 37067613 36627606 36017677 35477799
            36767811 37557755