|Mesoscale Discussion 1557|
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Mesoscale Discussion 1557
NWS Storm Prediction Center Norman OK
0146 AM CDT Mon Aug 24 2020
Areas affected...portions of the FL Panhandle
Concerning...Severe potential...Watch unlikely
Valid 240646Z - 240915Z
Probability of Watch Issuance...20 percent
SUMMARY...A waterspout could impact beaches from Franklin County
toward Walton County over the next few hours. However, the tornado
threat should remain low inland, away from the immediate coast.
DISCUSSION...A band of thunderstorms associated with an area of low
level confluence on the eastern periphery of Tropical Storm Marco
has persisted for several hours. Areas of low level rotation have
been noted in velocity data from KTLH. VWP data shows enlarged low
level hodographs with 0-1 km SRH values from around 100-200 m2/s2.
However, east/northeasterly low level flow is maintaining generally
low 70s F dewpoints across the region for now. This is limiting
surface-based instability, with SBCAPE values as high as 1000 J/kg
possible near the immediate coast, per modified 06z TLH sounding.
While a waterspout moving onshore cannot be ruled out, the
expectation is that any tornado activity will be confined to the
immediate coast and generally be weak and short-lived. As convection
moves inland, conditions will quickly become less favorable for
maintenance of low level rotation and tornado activity in the
absence of deep/richer low level dewpoints. Trends will continue to
be monitored, but a tornado watch does not appear necessary at this
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 29318504 29518545 29708569 30028610 30278632 30538622
30618571 30448487 30188440 29998427 29608431 29368446
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