AWUS01 KWNH 070454
FFGMPD
SCZ000-FLZ000-GAZ000-071100-

Mesoscale Precipitation Discussion 1134
NWS Weather Prediction Center College Park MD
1154 PM EST Wed Nov 06 2024

Areas affected...Southeast GA...Eastern SC...Eastern FL
Panhandle...

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

Valid 070500Z - 071100Z

SUMMARY...Flash flooding likely to continue with slow
moving/stationary PRE-like precipitation shield.  Embedded
convective cells with 2-2.5"/hr may result in 5-8" totals thru 12z
resulting in significant flash flooding.

DISCUSSION...Regional RADAR mosaic depicts a broad mesoscale
complex across stretching from the central GA/FL state line
through southeast GA into the coastal plain of SC.  Frontal-like
features are starting to be more well defined, with surface 04z
surface analysis suggesting a weak low near VDI as well as a
meso-low responding to very strong convective complex near VLD.  A
surface trof/effective developing front extends northeast through
the pressure trof to about DYB/CHS providing a favorable boundary
for further ascent.=20

RAP analysis continues to denote a very strong divergence
signature at the right entrance of a passing polar jet across the
Carolinas along with modest diffluent pattern over SE GA/N FL as
contribution from anticyclonically curved outflow jet from
periphery of approaching Tropical Cyclone Rafael.   This
divergence signal is slowly lifting north east, but its
contribution to the development of the sfc to low level wave and
encouragement of strengthening southeasterly confluent return
moisture flow off the Gulf stream, is providing deep moisture flux
convergence and isentropic ascent across the aforementioned
boundary.  CIRA LPW shows a marked increase in moisture generally
parallel to the FL coast with 1.15" Sfc to 850mb moisture advected
northeast on 25-30kts orthogonal to the boundary and as far
northwest into GA toward Macon, GA.  CIRA LPW also notes that
solid core of 700-300mb moisture resides across the northeast Gulf
through South Carolina resulting in total values over 2-2.25".=20
While the profile is solidly saturated, there is sufficient low
level heating to support weak to modestly unstable air with
750-1250 J/kg of MLCAPE remaining along and southeast of the
boundary, so embedded convective elements will remain likely
through the overnight period...likely with SE to NE 'finger-like'
filaments as the overall onshore flow is strong to support about
5kts of southeast propagation.

This will allow for a broad complex of moderate showers to remain
across SE GA into SC where heavy rainfall has already resulted in
flash flooding conditions additional 2-4" totals on .5-1"/hr rates
can be expected.  However, it is those embedded convective
elements with back-building that are of greatest concern.  Overall
trends would suggest band of confluence showers/TCus off the Gulf
stream lifting north into SW SC will likely result in the greatest
potential totals, nearly all 00z Hi-Res CAMs support a localized
maxima in the vicinity from Bulloch to Colleton counties (HREF
neighborhood probability of 5"/6hr over 50%), providing solid
confidence there.

However, a secondary area of concern along the southern-most
flanking line of the effective boundary in south-central GA
remains a bit less certain...but already been very prolific near
Valdosta, GA.  With an exiting shortwave/right entrance region,
there remains some veering of low level flow to maximize sfc to
boundary layer moisture flux convergence in proximity to the
greatest remaining instability pocket across the eastern portion
of the FL panhandle across southern GA.  Isallobaric response will
likely remain the driver of this flux convergence and risk for
2-3"/hr rates.  Deeper layer flow suggests this area of
convergence will drift north and westward toward an area of
lowered FFG values from prior heavy rainfall recently.  As such,
while confidence that this area will be able to maintain relative
to areas northward, the risk for more isolated but heavier
rainfall rates and excessive totals remains.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!4QsiGC3P41EoUF092UQbYMadJ1b-Rn0SDXhUK7WFfXdGOHCXlWbPqjrOrkAdh1t8Uru8=
qLQyBbT48o6r3EM9gbuI7rw$  for graphic product...

ATTN...WFO...CAE...CHS...FFC...ILM...JAX...TAE...

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

LAT...LON   34418013 33867906 33207910 32527986 31658092=20
            31008134 31078194 31048223 30238340 30218414=20
            30898440 32148370 33078284 34108136=20

=3D =3D =3D
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