470
AWUS01 KWNH 121201
FFGMPD
SCZ000-121530-

Mesoscale Precipitation Discussion 1186
NWS Weather Prediction Center College Park MD
801 AM EDT Sun Oct 12 2025

Areas affected...central/northern SC coast

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

Valid 121159Z - 121530Z

Summary...Localized high rain rates will continue a localized
flash flood threat for the central and northern coastline of SC
for another few hours. Hourly rainfall of 2-3 inches can be
expected at times.

Discussion...Localized heavy rain in and southeast of Georgetown
has resulted in MRMS estimates of 6 to 10 inches since midnight,
with a few Wunderground.com observations showing 6-7 inches in the
city and along the coast. A strong surface low (991 mb) has been
slow moving and was analyzed 115 miles east of Georgetown at 11Z
and a slow moving low level convergence axis has focused an area
of heavy rain containing hourly rainfall between 2-3 inches over
coastal Georgetown County over the past couple of hours. While
some weakening has occurred, VAD wind data showed ~50 kt of
925-850 mb winds oriented from the northeast, parallel to the
coast at KTLX, veering to a weaker and more perpendicular
orientation at KCLX. Aloft, a potent divergence maximum was
located along the coast of the Carolinas within the left-exit
region of a 90-100 kt jet streak, east of an upper low located
over the FL/GA border.

Short term RAP forecasts show the surface low finally begins to
make some northward progress over the next 6 hours along with a
disruption to the nearly stationary low level convergence axis due
to further weakening of the low level flow over southern NC and
veering of the low level winds along the central SC coast over the
next few hours. This should allow hourly rainfall values to lessen
while translating southward through 15Z. Until then however,
continued slow movement of heavy rain will maintain a localized
flash flood threat along the Grand Strand with additional rainfall
of 3 to 6 inches possible before expected weakening of rainfall
intensities.

Otto

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

ATTN...WFO...CAE...CHS...ILM...

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

LAT...LON   33947966 33887900 33737869 33557848 33107858
            33007873 32907930 33058024 33238047 33468048
            33698029 33888006