SPC AC 040929
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0429 AM CDT SAT SEP 04 2004
   
   VALID 061200Z - 071200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...UPPER MS VALLEY/WRN GREAT LAKES...
   SHORT WAVE TROUGH IS FORECAST TO WEAKEN AS IT LIFTS NEWD ACROSS THE
   WRN GREAT LAKES ON MONDAY WHILE ZONAL FLOW DEVELOPS OVER THE
   NWRN/NORTH CENTRAL PARTS OF THE CONUS. THE ASSOCIATED COLD FRONT IS
   EXPECTED TO PROGRESS EWD ACROSS THE WRN LAKES AND MIDDLE MS VALLEY. 
   MOIST LOW LEVEL AIR MASS WILL CONTINUE AHEAD OF THE FRONT WITH
   SURFACE DEW POINTS IN THE 60S...HOWEVER INSTABILITY WILL BE TEMPERED
   BY WEAK LAPSE RATES LIMITING MLCAPE TO NEAR 1000 J/KG. A FEW STRONG
   THUNDERSTORMS MAY DEVELOP ALONG/AHEAD OF THE COLD FRONT FROM UPPER
   MI SWWD INTO NRN IL/ERN IA BUT WEAKENING UPPER TROUGH AND
   DIMINISHING VERTICAL SHEAR SHOULD REDUCE OVERALL SEVERE THREAT.
   
   ...AL/GA/NRN FL...
   NHC GUIDANCE INDICATES THE CIRCULATION ASSOCIATED WITH FRANCES WILL
   MOVE FROM NWRN FL INTO AL ON MONDAY.  ALTHOUGH THE SYSTEM IS
   EXPECTED TO FILL AS IT MOVES INLAND THE ETA/GFS/GFDL MODELS ALL
   INDICATE 850 MB WINDS AOA 50 KT AND STRONG LOW LEVEL SHEAR WILL
   PERSIST WITHIN THE NRN/ERN SEMICIRCLE OF THE SYSTEM.  IF REGIONS OF
   ENHANCED HEATING/DESTABILIZATION CAN OCCUR WITHIN THE FAVORABLE ZONE
   OF LOW LEVEL SHEAR THERE WILL BE POTENTIAL FOR SUPERCELLS TO DEVELOP
   WITH ATTENDANT RISK OF TORNADOES.  INCREASED UNCERTAINTY IN EXACT
   TRACK OF SYSTEM AND DETAILS OF MESOSCALE ENVIRONMENT IN DAY 3 PERIOD
   PRECLUDE ISSUANCE OF MORE THAN MARGINAL SEVERE PROBABILITIES ATTM.
   
   ..WEISS.. 09/04/2004
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED FOR 1100Z