925
AWUS01 KWNH 180216
FFGMPD
FLZ000-GAZ000-180730-

Mesoscale Precipitation Discussion 0285
NWS Weather Prediction Center College Park MD
1015 PM EDT Fri May 17 2024

Areas affected...Southern GA... Northern FL incl. the eastern FL
Panhandle...

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

Valid 180215Z - 180730Z

SUMMARY...Lingering thunderstorms with some potential for upstream
redevelopment and short-term training may continue a low-end
localized flash flooding concern through the early Saturday.

DISCUSSION...RADAR Mosaic depicts a mature to weakening MCS
crossing southern GA with a few stronger updrafts and overshooting
tops maintaining along the southern and upstream southwesterly
flank of the complex.  Continued hourly rates of 2"/hr continue to
shrink in areal coverage, but convergence along the leading line
remains sufficient to tap the remaining uncapped or weakly capped
2000 J/kg CAPE across S GA into far Northeast FL.  Oblique
convergence may reduce magnitude, yet the deeper steering flow
from WSW to SW still allows for prolonged duration with
training/repeating allowing for spots of 2-4" for the next few
hours as instability further wanes.

Upstream across central FL panhandle, the outflow of the trailing
edge does lay orthogonal to the low level isentropic ascent.  VWP
from EVX and TLH shows the isentropic ascent from the southwest is
ideally oriented to the deep layer moisture axis where TPWs remain
at 2-2.2" and very unstable 3000 J/kg MLCAPEs to allow for
stronger updrafts.  10.3um EIR loop shows a few deeper cells, but
they are weaker and scattered; yet there remains some potential
for further expansion.  This would continue to repeat over areas
along I-10 that have already seen heavy rainfall capable of flash
flooding; so any further upstream redevelopment should maintain
that flooding concern.  Further south and east, lack of recent
rains and naturally high infiltration soils are likely to limit
any FF risks south of I-10 with exception of urban centers.  As
such, flash flooding is considered possible.

Hi-Res CAMs (particularly the HRRR which has tended to have the
best handle on the current evolution)  suggest slow weakening as
low level inflow wanes a bit between waves of forcing.  There is
uncertainty for the initiation and evolution of upstream
redevelopment over the Central Gulf States which may track through
the area later into the morning hours of Saturday and a subsequent
separate MPD may be required at that time.

Gallina

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

ATTN...WFO...JAX...TAE...

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

LAT...LON   31308213 31198144 30748140 30288143 30058170
            29878293 30008370 30118416 30038480 30198536
            30538559 30798528 30908421 31048333 31148294
            31198267