SPC AC 121736
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1136 AM CST WED JAN 12 2005
   
   VALID 131200Z - 141200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 SSW
   LCH ESF 30 SSE GLH MEM BNA ATL ABY AQQ.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 SSW BPT MLU DNV 25
   NE MTC ...CONT... 20 NNE ROC 30 NNW ELM 15 SSW LBE 10 N CRW BKW SHD
   20 SSW JFK ...CONT... 30 ESE ECG 30 SSE EWN ...CONT... 45 NNW DAB 40
   N PIE.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THURSDAY ACROSS PARTS OF THE
   CNTRL/ERN GULF STATES....
   
   MODELS CONTINUE TO INDICATE THE EVOLUTION OF A DEEP CLOSED LOW OVER
   THE EAST CENTRAL CANADIAN PROVINCES BY EARLY  FRIDAY...WITH A BROAD
   CYCLONIC FLOW REGIME ENCOMPASSING MUCH OF CANADA AND THE UNITED
   STATES.  THIS IS SUPPORTED BY TRENDS IN LATEST SATELLITE IMAGERY...
   AND WILL INVOLVE THE EVENTUAL PHASING OF CLOSED LOWS/SHORT WAVE
   TROUGHS EMBEDDED WITHIN NORTHERN AND SOUTHERN BRANCHES OF THE POLAR
   WESTERLIES.
   
   VIGOROUS SOUTHERN BRANCH SYSTEM IS CURRENTLY PROGRESSING EAST OF THE
   CENTRAL/SOUTHERN ROCKIES...GENERALLY IN PHASE WITH IMPULSE EMBEDDED
   WITHIN SUBTROPICAL BRANCH OF THE WESTERLIES.  HOWEVER... BY EARLY
   THURSDAY MORNING...MODELS SUGGEST TROUGHING IN SUBTROPICAL BRANCH OF
   WESTERLIES WILL BE SLOWER TO PROGRESS EAST OF THE WESTERN GULF OF
   MEXICO...AS MORE SIGNIFICANT PORTION OF TROUGH BEGINS TO ACCELERATE
   NORTHEASTWARD TOWARD THE LOWER GREAT LAKE REGION.
   
   PRIMARY SURFACE CYCLOGENESIS ACROSS EAST CENTRAL CANADA WILL PROCEED
   THURSDAY...WITH DEEPENING/OCCLUDING SURFACE LOW LIFTING ACROSS
   EASTERN HUDSON BAY/NORTHERN QUEBEC.  SURFACE COLD TRAILING INTO THE
   U.S. WILL PROGRESS EAST OF THE MISSISSIPPI VALLEY ...ADVANCING
   ACROSS THE APPALACHIANS AND INTO ATLANTIC COASTAL AREAS BY EARLY
   FRIDAY.  INITIAL WAVE ALONG FRONT ASSOCIATED WITH SOUTHERN BRANCH
   SYSTEM IS PROGGED TO WEAKEN ACROSS THE OHIO VALLEY/LOWER GREAT LAKES
   REGION DURING THE DAYTIME HOURS.  WITH SURFACE RIDGING SLOW TO
   WEAKEN ACROSS EASTERN GULF/SOUTH ATLANTIC COASTAL AREAS...MODELS
   INDICATE NO ADDITIONAL SIGNIFICANT WAVE DEVELOPMENT ALONG FRONT
   UNTIL...PERHAPS...LATE THURSDAY EVENING/NIGHT IN THE LEE OF THE
   SOUTHERN APPALACHIANS...AS SUBTROPICAL SHORT WAVE TROUGH APPROACHES.
   
   
   ...OHIO VALLEY INTO LOWER GREAT LAKES...
   GIVEN BROAD SURFACE WARM SECTOR IN PLACE TO THE WEST OF THE
   APPALACHIANS... FORCING ASSOCIATED WITH SOUTHERN BRANCH TROUGH IS
   EXPECTED TO SUPPORT EVOLUTION OF EXTENSIVE SQUALL LINE LATE TODAY
   THROUGH EARLY THURSDAY.  BY 12Z THURSDAY MORNING...MODELS ARE VERY
   SIMILAR IN SUGGESTING ACTIVITY WILL EXTEND FROM LOWER MICHIGAN TO
   LOUISIANA.  CONVECTION SHOULD BE IN THE PROCESS OF WEAKENING
   ...AND...IN FACT...MOIST/WEAK LAPSE RATE THERMODYNAMIC PROFILES FROM
   THE OHIO VALLEY NORTHWARD MAY CEASE TO SUPPORT SIGNIFICANT
   THUNDERSTORM ACTIVITY.
   
   HOWEVER...VERY WEAK CAPE /GENERALLY ON THE ORDER OF A FEW HUNDRED
   J/KG OR LESS/ IN LOWER LEVELS OF WARM SECTOR WILL REMAIN SUPPORTIVE
   OF CONVECTION ALONG FRONT.  GIVEN INTENSE LOW-LEVEL WIND
   FIELDS...WITH MODELS SUGGESTING 70-80 KT LOW-LEVEL JET LIFTING FROM
   THE LOWER OHIO VALLEY TO THE LOWER GREAT LAKES REGION...POTENTIAL
   FOR DAMAGING WINDS MAY PERSIST WITH CONVECTIVE BAND/FRONT.  THIS
   SHOULD CONTINUE AT LEAST INTO EARLY THURSDAY EVENING AS FRONT
   ADVANCES THROUGH CREST OF THE NORTHERN APPALACHIANS.
   
   ...TENNESSEE VALLEY INTO GULF COAST STATES...
   WITH SHORT WAVE ASSOCIATED WITH SOUTHERN BRANCH OF POLAR WESTERLIES
   LIFTING TOWARD THE LOWER GREAT LAKES REGION EARLY IN THE DAY...WIND
   FIELDS WILL NOT BE NEARLY AS STRONG TO THE SOUTH OF THE OHIO VALLEY.
    HOWEVER...WITH SUBTROPICAL IMPULSE LAGGING UPSTREAM ...MID/UPPER
   FORCING LIKELY WILL MAINTAIN PRE-FRONTAL CONVECTIVE LINE THROUGH THE
   DAY...EASTWARD ACROSS THE GULF STATES.
   
   THOUGH MID-LEVELS WILL REMAIN RELATIVELY WARM...VERY MOIST BOUNDARY
   LAYER WITH MID/UPPER 60S DEW POINTS IS EXPECTED TO CONTRIBUTE TO
   CAPE AS HIGH AS 1000 J/KG.  THIS WILL SUPPORT VIGOROUS UPDRAFTS
   PRIMARILY WITH HEAVY RAIN...BUT SOME HAIL WILL BE POSSIBLE IN
   STRONGEST STORMS.  30 TO 50 KT LOW-LEVEL JET COULD STILL CONTRIBUTE
   TO DAMAGING WIND POTENTIAL...AND THIS APPEARS PRIMARY SEVERE THREAT
   AS SQUALL LINE PROGRESSES THROUGH THE SOUTHEAST.
   
   ISOLATED SUPERCELLS WILL BE POSSIBLE IMMEDIATELY AHEAD OF SQUALL
   LINE...BUT THIS THREAT APPEARS LOW DUE TO SLOW EROSION OF SURFACE
   RIDGE.
   
   ..KERR.. 01/12/2005
   
   ...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 2 OUTLOOK IS SCHEDULED BY 0800Z