086
ACUS01 KWNS 271957
SWODY1
SPC AC 271956
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0256 PM CDT TUE SEP 27 2022
VALID 272000Z - 281200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL AND
SOUTHERN FLORIDA...
..SUMMARY
TORNADOES ARE POSSIBLE ACROSS THE FLORIDA KEYS AND SOUTH FLORIDA
THIS AFTERNOON, AND MAY SPREAD INTO PARTS OF CENTRAL FLORIDA
OVERNIGHT WITH HURRICANE IAN.
..DISCUSSION
ASIDE FROM ADJUSTMENTS IN THE THUNDER AREA -- PARTICULARLY ACROSS
THE TEXAS SOUTH PLAINS AREA AND EASTERN LOWER MICHIGAN -- THE
FORECAST AREAS AND REASONING LAID OUT IN PRIOR OUTLOOKS CONTINUE TO
REFLECT THE EVOLVING SCENARIO.
IN THE PAST HOUR OR SO, SEVERAL ROTATING CELLS HAVE EVOLVED ACROSS
SOUTH FLORIDA, WITHIN ONE OF THE MORE PROMINENT CONVECTIVE BANDS
ROTATING AROUND IAN'S CENTER, CONTRIBUTING TO THE
ANTICIPATED/GRADUAL INCREASE IN TORNADO POTENTIAL. THE POTENTIAL
SHOULD EXPAND NORTHWARD WITH TIME, AS IAN ADVANCES
NORTH-NORTHEASTWARD.
..GOSS.. 09/27/2022
PREV DISCUSSION
/ISSUED 1126 AM CDT TUE SEP 27 2022/
..SOUTH FL AND THE KEYS THROUGH TONIGHT
MAJOR HURRICANE IAN WILL MOVE NORTHWARD OR NORTH-NORTHEASTWARD
THROUGH TONIGHT ACROSS THE EXTREME SOUTHEAST GULF OF MEXICO, AS RAIN
BANDS EAST-THROUGH-NORTHEAST OF THE CENTER CONTINUE TO OVERSPREAD
SOUTH FL AND THE KEYS. SOME EXPANSION OF THE STRONGER WIND FIELD,
AND RESULTANT STRONGER VERTICAL SHEAR (EFFECTIVE SRH OF 200-400
M2/S2), WILL OCCUR THROUGH TONIGHT AS IAN CONTINUES TO DEEPEN (SEE
LATEST NHC ADVISORIES FOR ADDITIONAL INFORMATION). WIDESPREAD RAIN
ACROSS SOUTH FL HAS HELD SURFACE TEMPERATURES IN THE MID 70S THROUGH
THE MORNING WITH MINIMAL SURFACE-BASED BUOYANCY. HOWEVER, SOME
CLOUD BREAKS AND MODEST SURFACE HEATING IS UNDERWAY ACROSS THE KEYS,
AND SHOULD DEVELOP SLOWLY INLAND FROM THE SOUTHEAST FL COAST THROUGH
THE AFTERNOON. LIKEWISE, SLIGHTLY HIGHER BOUNDARY-LAYER DEWPOINTS
(>76 F) WILL SPREAD INLAND, WITH SUFFICIENT DESTABILIZATION TO
SUPPORT SUPERCELLS MOVING INLAND. THUS, THE THREAT FOR TORNADOES IS
EXPECTED TO GRADUALLY INCREASE FROM SOUTH-TO-NORTH LATER THIS
AFTERNOON/EVENING, AND PERSIST INTO THE OVERNIGHT HOURS. PLEASE SEE
SPC MD 1833 FOR ADDITIONAL DETAILS.
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