383
AWUS01 KWNH 121829
FFGMPD
VAZ000-NCZ000-130027-

Mesoscale Precipitation Discussion 0659
NWS Weather Prediction Center College Park MD
227 PM EDT Sat Jul 12 2025

Areas affected...Central to Southeast VA...Northeast NC

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

Valid 121827Z - 130027Z

SUMMARY...Slow-moving showers and thunderstorms will continue to
locally expand in coverage over the next few hours. Additional
areas of flash flooding are expected which will include urban
flooding concerns.

DISCUSSION...Radar imagery shows multiple clusters of heavy
showers and thunderstorms continuing to develop and evolve across
areas of central to southeast VA along with northeast NC. This
convection is focusing within a very moist and unstable
environment with proximity of a weak area of low pressure and
surface trough helping to provide moderately strong low-level
forcing/convergence.

MLCAPE values of 2000 to 3000 J/kg are in place with the aid of
strong diurnal heating, and PWs are on the order of 1.75 inches.
Much of the activity is pulse in nature with a lack of shear, but
the rainfall rates are very high with rates of 1.5 to 2.5
inches/hour given the moist/unstable environment.

Some additional expansion of convection is expected over the next
few hours given persistence of the low-level trough and also with
potential for some outflow boundary collisions that may help
induce additional regional scale convective development. The
threat area should generally encompass central to southeast VA and
northeast NC through this evening before eventually the
instability is exhausted and the convective threat wanes.

Until then, some additional rainfal totals of 2 to 4 inches will
be possible. And this will favor some additional areas of isolated
to scattered flash flooding, which will include the more urbanized
locations. This will include the Richmond metropolitan area where
flash flooding has already been occurring over the last 60 to 75
minutes.

Orrison

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...AKQ...LWX...MHX...RAH...RNK...

ATTN...RFC...ALR...RHA...NWC...

LAT...LON   38297777 37987708 37397660 36747639 35967600
            35537609 35587699 36527794 37257883 37937896
            38287846