Mesoscale Precipitation Discussion 0270
NWS Weather Prediction Center College Park MD
235 AM EDT Tue May 14 2024

Areas affected...FL Panhandle into northern FL/southern GA

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

Valid 140634Z - 141230Z

Summary...A localized flash flood threat will continue for the FL
Panhandle into northern FL/southern GA through 12Z. An additional
2-4 inches is expected in some of the same locations which picked
up heavy rain over the past 24 hours.

Discussion...GOES East infrared satellite and regional radar
imagery at 06Z showed an MCS tracking east along the central Gulf
Coast with an MCV located 70 miles SSE of Mobile Bay. While some
warming of cloud tops has been observed over the past 1-2 hours,
the coldest cloud tops and observed lightning strikes have been
confined to along and just south of the AL/MS into the western FL
Panhandle coast, co-located with a gradient in MLCAPE and
quasi-stationary front. SPC mesoanalysis data from 06Z showed
MLCAPE values of roughly 500-1000 J/kg across coastal regions of
AL into the FL Panhandle and Big Bend region. This region also
resided within the diffluent and divergent portion of a RAP
estimated 110-130 kt jet max aloft centered over northern portions
of the lower MS Valley.

WSW low to mid-level flow should take the MCV east-northeast along
a similar path as the surface front, reaching southern GA/northern
FL toward 12Z. Expect the MCS to continue its forward speed of
30-40 kt with rainfall rates of 1-3 in/hr, with the upper values
of that range reserved for training ahead of the MCV circulation,
contained within the better instability values near the coast
(through ~10Z) and eventually northern FL into southern GA as
instability increases with low level moisture advection ahead of
the advancing MCS.

There is general consensus of this scenario in the latest hires
model guidance, but recent runs of the HRRR appear to slow to
progress convection downstream. Nonetheless, there may be a
lowering of the flash flood threat through 12Z as the MCS
approaches drier antecedent ground conditions along with a
possible increased forward speed. Portions of the central Gulf
Coast into the FL Panhandle, northern FL and southern GA have
received roughly 2-4 inches over the past 24 hours and the
addition of another 2-4 inches through 12Z may result in localized
flash flooding.

Otto

ATTN...WFO...JAX...MOB...TAE...TBW...

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

LAT...LON   31388164 31068127 30668132 29888123 29388271
            29328454 29328539 29858687 29968761 30668748
            30998638 31258416 31368242