MD 0663 CONCERNING SEVERE POTENTIAL…TORNADO WATCH LIKELY FOR FLORIDA PENINSULA
Mesoscale Discussion 0663
NWS Storm Prediction Center Norman OK
0332 AM CDT Sun Apr 30 2023
Areas affected...Florida Peninsula
Concerning...Severe potential...Tornado Watch likely
Valid 300832Z - 301030Z
Probability of Watch Issuance...80 percent
SUMMARY...Increasing thunderstorm coverage is expected across the
Florida Peninsula. Severe thunderstorms are possible, with an
attendant risk for all hazards, including tornadoes. A Tornado Watch
will likely be needed across the region within the next hour.
DISCUSSION...The airmass across the Florida Peninsula continues to
destabilize amid low-level moisture advection ahead of the
approaching shortwave trough. Recent surface observations reveal
dewpoints ranging from the low 70s across the west coast and south
FL, dropping to the mid 60s across the northeast peninsula.
Dewpoints have increased 2-3 degrees F over the past 3 hours across
much of the peninsula. This increase in low-level moisture has
eroded any convective inhibition, while also contributing to
moderate buoyancy. Recent mesoanalysis estimates MLCAPE around 1000
J/kg across much of peninsula, increase to over 1500 J/kg across
south FL. As a result, an increase in thunderstorms is anticipated
as lift associated with the approaching shortwave interacts with
this moist, uncapped, and unstable environment.
A strong subtropical jet accompanying the shortwave also extends
over the region, supporting robust and deep southwesterly flow aloft
and strong vertical shear. Recent TBW and MLB VAD profiles both
sampled over 50 kt of 0-6 km bulk shear. These VAD profiles also
sampled strong low-level flow, with over 60 kt at 1 km AGL.
The combination of moderate buoyancy and strong vertical shear
supports the potential for organized severe thunderstorms. These
storms are possible in one or more southwest-to-northeast oriented
convective lines. Even so, given that the deep-layer shear is
largely perpendicular to the anticipated convective line, an initial
cell-in-line mode appears possible. Some potential exists for more
discrete development ahead of these lines as well. The strong
low-level shear suggest tornadoes are possible, as well as damaging
wind gusts within any bowing segment. Some isolated hail may also
occur. Given these threat, a Tornado Watch will likely be needed
across the region within the next hour.
..Mosier/Edwards.. 04/30/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MFL...MLB...KEY...TBW...JAX...
LAT...LON 29018290 29768241 30078143 28628072 26128000 25438008
25078027 24808061 24588105 24498191 25788172 26088182
26948243 27638274 29018290
