166
AWUS01 KWNH 011810
FFGMPD
SCZ000-FLZ000-GAZ000-020000-

Mesoscale Precipitation Discussion 0533
NWS Weather Prediction Center College Park MD
210 PM EDT Mon Jul 01 2024

Areas affected...Coastal Georgia and South Carolina...

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

Valid 011810Z - 020000Z

SUMMARY...Very deep moisture and slow thunderstorms along the
coast to produce 2.5"/hr, spots of 3-5", and possible rapid
inundation flooding through the evening.

DISCUSSION...18z surface analysis depicts a slowly sagging cold
front across the NC/SC border connecting to a weak surface
wave/inverted trough across West-central GA just west of Macon.
South of the boundary, very high theta-E air with mid to upper 70s
Tds and temperatures starting to near the mid to upper 80s, spots
of 90+F.  Total moisture through depth ranges from 2.1 to 2.5" and
SBCAPEs of 2500-3500 J/kg from CHS into S GA.  Deep warm layer
between 14-15Kft and given parameters will allow for efficient
rainfall production/tropical showers capable of 2.5"+/hr.

Aloft, GOES-E WV shows the split in upper-level flow in the col
along the eastern edge of the large scale ridge across the central
Gulf states.  This is weakening mid-level steering flow to allow
for very slow cell motions and propagation vectors to near zero at
or along the GA/SC coastline.  Yet, effective bulk shear given
directional shear should support some minor organization to
convective cells allowing for increased duration for multiple
up/down convective cycles before forward propagation would occur.
As such, a weak low to mid-level circulation is spinning up in
across S central GA, leading to streamline convergence across SE
GA as well.

Frictional convergence and onshore flow/moisture flux may further
lock convection to coastal regions to support increased rainfall
duration.  As such, spots of 3-5" are becoming more likely
particularly further north along the central SC coast (proximity
to the front) and northeast GA.  This is supported by recent HRRR
solutions as well as 17z WoFS; with 50th percentile around 3.5"
and 90th percentile over 6".  As such, there is increasing
confidence of 3-5" totals along the coast which may result in
spots of possible rapid inundation flooding.

Gallina

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

ATTN...WFO...CHS...ILM...JAX...

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

LAT...LON   33607902 33407895 32937934 31878086 30918145
            30668251 31058264 31818204 32678138 33078076
            33268021 33507975 33587949