Mesoscale Precipitation Discussion 0697
NWS Weather Prediction Center College Park MD
520 AM EDT Mon Jul 13 2026
Areas affected...Western NC...Far Southwest VA
Concerning...Heavy rainfall...Flash flooding possible
Valid 130920Z - 131520Z
SUMMARY...Areas of flash flooding will continue to be possible
this morning from slow-moving showers and thunderstorms with high
rainfall rates.
DISCUSSION...GOES-E IR satellite imagery in conjunction with radar
continues to show areas of slow-moving showers and thunderstorms
with high rainfall rates across portions of the southern
Appalachians and adjacent Piedmont area of the southern
Mid-Atlantic. This continues to be driven by close proximity of a
mid-level trough/closed low over the TN Valley which is yielding
some broadly divergent flow aloft across the region.
Meanwhile, there is plenty of deep moisture in place, with high
PWs of near 2 inches. This coupled with modest instability (MUCAPE
values of 500 to 1000 J/kg) and upslope flow into the eastern
slopes of the higher terrain continues to facilitate very
efficient convection with high rainfall rates.
The latest hires model guidance including the recent HRRR
solutions and the 06Z HREF/REFS solutions suggest the current
activity over western NC and far southwest VA should tend to
persist through the morning hours given some of the orographically
favored upslope flow and modest deep layer ascent associated with
the nearby TN Valley energy. However, the rainfall rates may be a
tad lower compared to earlier given the net decrease in
instability.
Regardless, some additional areas of convection will be capable of
producing 1 to 2 inch/hour rainfall rates given the setup. Slow
cell-motions and terrain-focused convection may lead to some
additional spotty totals this morning of 3 to 4 inches. This will
promote additional potential for areas of flash flooding.