061
AWUS01 KWNH 091731
FFGMPD
FLZ000-092300-

Mesoscale Precipitation Discussion 1171
NWS Weather Prediction Center College Park MD
130 PM EDT Thu Oct 09 2025

Areas affected...Southeast to Southern Peninsular Florida...

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

Valid 091730Z - 092300Z

SUMMARY...Slow moving thunderstorms within a deeply rich moisture
environment along inverted trof/tropical wave, will focus for some
2-3"/hr rates and localized totals of possible 5" may result in
rapid inundation flooding conditions through the afternoon.

DISCUSSION...GOES-E Visible loop and 17z surface analysis depicts
a confluent SW to NE axis extending across the Everglades toward
the southern Space Coast with increasing convective activity
concentrating along it.   Low level tropical moisture exists
through solid depth with mid 70s in surface and sfc-850mb LPW
values near 1".  This continues through 700mb, but along that
confluence line/inverted trof, mid-level dry air from the
northeast in the 700-500mb layer demarcates the boundary even
further, south of which, the TPW values are over 2.25" nearing
2.4" locally.  Solid early morning sun and limited capping on the
skinny profiles has brought temperatures well in the mid to upper
80s and support MLCAPEs of 2000-2500 J/kg even with fairly moist
adiabatic profiles.

The streamline flow noted in satellite, is generally 10-20kts per
VWP providing strong moisture flux convergence through depth along
the axis for scattered to numerous updrafts.  Flow aloft is
reverse to the low level flow providing some vertical shear but
not ideal for prolonged organized structures but the tilt will
allow for some upper-level divergence/outflow to maintain stronger
updrafts.  As such, the strength of flux convergence and depth of
moisture in deep warm cloud (13-15Kft) will support efficient
rainfall production with capability of 2-3"/hr rates.  Cell
motions suggest east to west transient 15kt cell motions, but
linear confluence features would support some repeating/training
to allow for some localized 5"+ totals, with the 16z HRRR even
suggesting localized totals over 7", so it is not completely out
of the realm of possibility if training is prolonged/ideal but
given the nature of the flow is still less likely than more.
Irrespective, the intensity of the rates into the 3"/hr range
would still result in localized rapid inundation flooding
especially in the east coast urban corridor, but also could affect
portions of Alligator Alley and other cross peninsular roadways.

Gallina

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

ATTN...WFO...MFL...MLB...TBW...

ATTN...RFC...ALR...NWC...

LAT...LON   28178090 28128055 27788035 27338016 26907999
            26047999 26048056 25998104 26028147 26378168
            26928149 27288137 27668127 27898117