MESO: Heavy rain Flash flooding possible FL Peninsula
From
Mike Powell@618:250/6 to
All on Thu Apr 9 08:32:20 2026
AWUS01 KWNH 091025
FFGMPD
FLZ000-091500-
Mesoscale Precipitation Discussion 0085
NWS Weather Prediction Center College Park MD
624 AM EDT Thu Apr 09 2026
Areas affected...east-central FL Peninsula
Concerning...Heavy rainfall...Flash flooding possible
Valid 091017Z - 091500Z
Summary...Slow moving showers with possible embedded thunderstorms
are expected to focus isolated areas of heavy rain along the Space
and Treasure coasts through late morning. Localized hourly
rainfall of 2+ inches will be possible with storm totals of 2 to
4+ inches through 15Z, which may result in isolated flash flooding.
Discussion...Regional radar imagery at 10Z showed scattered
showers between southern Brevard County and southern St. Lucie
County. 10.3 micron satellite imagery indicated cloud tops over
land were relatively warm at -20 to -35 C, with an estimated cloud
depth of 9 km AGL based on RAP analysis soundings over the region.
Easterly winds of 20-30 kt in the 925-850 mb layer were oriented
perpendicular to the coast while mid-upper level flow was from the
west at a similar magnitude. This has set up favorable effective
shear profiles for organized cells although 0-8 km AGL mean layer
winds were about 5 kt or less, resulting in slow cell movement. In
addition, the alignment of showers with the low level wind has
also resulted in slow movement of heavy rain cores at times with
recent development near Vero Beach showing signs of a weak MCV
over eastern Indian River County. MRMS-derived and KVRB hourly
rainfall of 2-2.5 inches has been observed with nearly 2 inches of
rain in 32 minutes at KVRB ending 0940Z. Speed and weak
directional convergence near the surface was allowing for the
formation of quasi-transient bands of heavy rain within an
expanding pocket of MLCAPE between 500-1000 J/kg (06Z-10Z SPC
mesoanalyses) over the east coast of FL.
While the future existence of the weak meso-vortex near Vero Beach
is unknown, convergence in the surface to near-surface layer is
expected to continue a threat for slow moving showers with
embedded thunderstorms from Brevard County down to St. Lucie
County over the next 3-5 hours. However, the concentration of
heavy rain is expected to remain limited in spatial extent through
the morning hours. Any areas of flash flooding that develop are
likely to focus across urban and other areas of poor draining,
remaining localized in coverage.
Otto
ATTN...WFO...MLB...
ATTN...RFC...ALR...NWC...
LAT...LON 28608054 27788010 27008004 26998066 27908111
28528112
=3D =3D =3D
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* Origin: Project Scorpio TEST (618:250/6)