SPC MD 1689

MD 1689 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR SOUTHERN ALABAMA...FLORIDA PANHANDLE

Mesoscale Discussion 1689
NWS Storm Prediction Center Norman OK
0617 AM CDT Tue Sep 15 2020

Areas affected...Southern Alabama...Florida Panhandle

Concerning...Severe potential...Watch likely 

Valid 151117Z - 151345Z

Probability of Watch Issuance...95 percent

SUMMARY...The tornado threat will increase along the immediate coast
of Alabama and Florida this morning as Hurricane Sally approaches. A
tornado watch will likely be needed within the next hour.

DISCUSSION...The center of Hurricane Sally is currently located
about 100 statute miles to the south of Mobile, Alabama. Heavy bands
of rainfall surround the eye of Sally with the most notable band
located from near Gulf Shores, Alabama extending southeastward into
the northeastern Gulf of Mexico. Within this band, multiple
semi-discrete thunderstorms are ongoing and some appear to be
supercells. These storms will approach the coasts of Alabama and the
Florida Panhandle over the next couple of hours. The WSR-88D VWP at
Tallahassee and Eglin Air Force Base currently have a wind profile
that shows veering winds with height in the lowest 3 km AGL. This is
resulting in a 0-1 km shear near 20 kt. As Hurricane Sally
approaches, low-level shear will steadily increase. As a result, a
tornado threat will develop along the immediate coast. Further
inland, instability is less which will keep the greatest tornado
threat confined to the coastal areas for several hours.

..Broyles/Edwards.. 09/15/2020

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

ATTN...WFO...TAE...MOB...LIX...

LAT...LON   31458663 31108563 30668495 30108446 29708439 29508461
            29488507 29818560 30098616 30298699 30318804 30498831
            30718841 31118828 31348798 31448748 31458663 

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from SPC Forecast Products http://www.spc.noaa.gov/products/md/md1689.html