Dec-25-2004 1630 UTC Day 1 Convective Outlook
Updated: Sat Dec 25 16:38:10 UTC 2004
Categorical Graphic
20041225 1630 UTC Day 1 Outlook Graphic
Probablistic Tornado Graphic
20041225 1630 UTC Day 1 Tornado Probabilities Graphic
Probablistic Damaging Wind Graphic
20041225 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Probablistic Large Hail Graphic
20041225 1630 UTC Day 1 Large Hail Probabilities Graphic
   SPC AC 251633
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1033 AM CST SAT DEC 25 2004
   
   VALID 251630Z - 261200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 NNW
   PIE 10 NNE DAB.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 SE CEW 40 NNW TLH
   25 W SAV 30 SSW CHS.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FLORIDA PENINSULA...
   
   ...FL PENINSULA...
   
   VIGOROUS UPPER TROUGH/LOW HAS ENTERED NWRN GULF OF MEXICO AND WILL
   MOVE EWD CROSSING FL LATER TONIGHT.  AT THE SURFACE THE FRONTAL
   BOUNDARY THAT MOVED S OF THE FL KEYS OVERNIGHT...EXTENDS WNWWD TO
   SURFACE LOW NEAR 25N 90W AT 15Z.
   
   FRONT HAS BEGUN RETURN NWD INTO S FL AS A WARM FRONT AHEAD OF THE
   1006 MB LOW OVER CENTRAL GULF. WARM SECTOR EXPECTED TO OVERSPREAD S
   FL BY THIS EVENING AS FAR N AS A FMY TO VRB LINE WITH DEWPOINTS
   RISING TO AOA 70F AND TEMPERATURES TO NEAR 80F.
   
   12Z MODEL RUNS PROVIDING DIFFERING SOLUTIONS AS TO CONVECTIVE
   EVOLUTION AS GFS QUICKLY DEVELOPS STRONG CONVECTIVE SIGNAL TIED TO
   RETURNING WARM FRONT AND MOVES IT ACROSS CENTRAL FL PENINSULA BY 00Z
   WITH LOW LEVEL WINDS VEERING AND SURFACE LOW REDEVELOPING OVER
   ATLANTIC E OF FL.  ETA IS SLOWER ON DEVELOPING STRONG CONVECTIVE
   PCPN AND MORE ASSOCIATED WITH VIGOROUS UPWARD MOTION AHEAD OF
   TROUGH...WHILE MOVING GULF SURFACE LOW MUCH SLOWER AS WELL.
   
   WITH A HIGH QUALITY WARM SECTOR IN SERN GULF AND WRN CARIBBEAN...AND
   ACTIVE THUNDERSTORMS ONGOING VICINITY WARM FRONT VICINITY 25N
   86W...WELL AHEAD OF SURFACE LOW...FAVOR A SOLUTION MORE TOWARD THE
   GFS EXCEPT SLOWER WITH POTENTIAL FOR MCS DEVELOPMENT ALONG AND N OF
   WARM FRONT WHERE CURRENT CONVECTIVE ACTIVITY IS LOCATED. THIS WOULD
   BRING SEVERE THUNDERSTORM POTENTIAL TO WRN FL LATE THIS AFTERNOON
   AND EVENING VICINITY FMY.
   
   WHILE LAPSE RATES GENERALLY LESS THAN 6C/KM...THE WARM SECTOR WITH
   THE HIGH DEWPOINTS SUPPORTS MDT INSTABILITY WITH MUCAPES OFF W COAST
   FL S OF WARM FRONT CLIMBING TO ABOVE 2000 J/KG.  DEEP LAYER SHEAR
   INCREASES TO 60 KTS AND SR HELICITY TO 200-300 J/KG VICINITY OF THE
   WARM FRONT BY LATE THIS AFTERNOON AS LOW LEVEL JET INCREASES TO 40
   KT AND 500MB WINDS TO 50-60KT. THIS WILL SUPPORT SEVERE POTENTIAL
   WITH THUNDERSTORM COMPLEX MOVING ONSHORE ALONG WITH THREAT FOR
   TORNADOES AS WELL AS DAMAGING WINDS
   
   ADDITIONALLY MORE ISOLATED SEVERE STORMS COULD DEVELOP AHEAD OF GULF
   ACTIVITY AGAIN VICINITY WARM FRONT LATER THIS AFTERNOON ACROSS S FL.
   
   
   OVERNIGHT AS STRONG FORCING AHEAD OF SURFACE LOW AND UPPER TROUGH
   MOVE EWD THERE WILL BE POTENTIAL FOR MORE OF A SQUALL LINE
   DEVELOPMENT MOVING ACROSS THE CENTRAL PENINSULA WITH PRIMARILY A
   DAMAGING WIND THREAT.  ISOLATED TORNADOES WILL STILL BE POSSIBLE
   WITH SURFACE BASED CONVECTION  NEAR THE WARM FRONTAL BOUNDARY.
   
   ..HALES.. 12/25/2004
   
   ...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 1 OUTLOOK IS SCHEDULED BY 2000Z