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.  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page