764
AWUS01 KWNH 261648
FFGMPD
SCZ000-GAZ000-262200-

Mesoscale Precipitation Discussion 0850
NWS Weather Prediction Center College Park MD
1247 PM EDT Sun Jul 26 2026

Areas affected...Eastern South Carolina into extreme Southeast
Georgia

Concerning...Heavy rainfall...Flash flooding possible

Valid 261646Z - 262200Z

Summary...Showers and thunderstorms will expand across South
Carolina and drop slowly southeast through the afternoon. Short
term rainfall rates of 2-3"/hr are possible, leading to isolated
instances of flash flooding.

Discussion...The regional radar mosaic this afternoon shows rapid
expansion of elevated reflectivity associated with deepening
convection over the Lowcountry of South Carolina. Farther upstream
into the Midlands, the GOES-E experimental day-cloud phase RGB
indicates a slow coverage increase of mixed-phase and glaciating
clouds, suggesting additional convection is set to blossom across
the state. This activity is building along a stationary front
analyzed by WPC, with additional contribution to ascent being
provided by a wave of low pressure moving along the front with
weak mid-level vorticity support. This lift is occurring within
impressive thermodynamics characterized by PWs measured by GPS of
2.1 to 2.2 inches, above the 90th percentile for the date,
combined with MLCAPE that has surged to over 2000 J/kg within a
ribbon south of the wavering front.

This environment is likely to support additional convective
development during the next few hours, and this is reflected by
the majority of high-res CAM simulated reflectivity, albeit with
continued uncertainty into the placement and coverage of activity.
Despite that, it is more certain that any convection that does
develop will contain intense rain rates as reflected by both HREF
and REFS neighborhood probabilities reaching 30-50% for 2"/hr
rainfall, with the 15-min HRRR indicating at least short duration
rain rates above 3"/hr. Mean flow from the NW and aligned to the
stationary boundary suggests a training/repeating setup for
convection through the aftn. Additionally, as the sea breeze
develops and tries to push inland, it will serve as an additional
focus for convective development, and will likely result in
slowing or stalling storms near the coast where Corfidi vectors
drop to around 5 kts. This will support rainfall in a few areas
reaching 2-3", with localized amounts to 5" possible (10-15%
chance).

7-day rainfall has been around, to slightly below, normal across
much of the Midlands and Lowcountry, leading to FFG that is
elevated around 2-3"/1hr, and HREF exceedance probabilities peak
at only 10-20%. However, the training/slow movement of these
intense rain rates could still be sufficient to overcome this FFG,
with the greatest risk occurring near the coast/stalled storms or
across any urban areas with naturally less drainage.


Weiss

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

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

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

LAT...LON   33958043 33807997 33427951 33097940 32657978
            32228020 31968054 31878093 32098136 32428148
            32888161 33338158 33618137 33908102