SPC MD 939

MD 0939 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR SOUTHERN FLORIDA

Mesoscale Discussion 0939
NWS Storm Prediction Center Norman OK
1109 AM CDT Fri May 23 2025

Areas affected...southern Florida

Concerning...Severe potential...Watch unlikely 

Valid 231609Z - 231915Z

Probability of Watch Issuance...20 percent

SUMMARY...Strong thunderstorm development, possibly including an
isolated supercell or two, may initiate during the next 1-2 hours
along the Atlantic coast sea-breeze, particularly near or
north-northwest of the Palm Beach vicinity, before gradually
increasing through late afternoon across the interior southern
peninsula.

DISCUSSION...Deepening convective development is evident along the
Atlantic coast sea-breeze, south of Melbourne into the Palm Beach
vicinity.  This is where the latest objective analysis indicates
that mid-level inhibition is weakening in response to insolation, as
heating of a seasonably moist boundary layer contributes to
mixed-layer CAPE increasing in excess of 2000 J/kg.

Stronger low-level confluence/convergence currently appears focused
near/northwest of the Palm Beach vicinity, where isolated
intensifying thunderstorm development might be most probable through
17-18Z.  In the presence of moderate westerly shear, beneath broadly
cyclonic, 30+ kt westerly mid-level flow and relatively cool
mid-level temperatures, the evolution of a supercell posing a risk
for large hail and perhaps a brief tornado appears possible.

Thereafter, a gradual further increase in scattered thunderstorm
development appears possible with continued destabilization
along/ahead of slowly inland advancing Atlantic and Gulf coast
sea-breezes.  Aided by interactions with outflow and, perhaps,
gravity waves generated by earlier initiating convection, the
convective evolution remains unclear, but widely scattered stronger
cells across the interior southern peninsula may be accompanied by a
risk for marginally severe hail and locally damaging wind gusts.

..Kerr/Guyer.. 05/23/2025

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   27498104 28038058 26948002 25658004 25518074 25698082
            26098146 26618153 27048147 27498104 

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

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