Categorical Graphic
Probabilistic Tornado Graphic
Probabilistic Damaging Wind Graphic
Probabilistic Large Hail Graphic

   SPC AC 241955
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0255 PM CDT TUE APR 24 2007
   
   VALID 242000Z - 251200Z
   
   ...THERE IS A HIGH RISK OF SVR TSTMS LATE THIS AFTN/TONIGHT ACROSS
   PARTS OF CNTRL INTO NORTHEAST TEXAS....
   
   ...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK
   AREAS ACROSS A LARGE PART OF THE CNTRL/SRN PLAINS...INCLUDING PARTS
   OF CNTRL/ERN KS AND OK...TX...NW LA...WRN AR...AND SW MO....
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS A LARGE PART OF THE
   CNTRL PLAINS INTO THE MIDDLE/LWR MISSISSIPPI VALLEY....
   
   ...SYNOPSIS...
   DEEP CYCLONE TO THE LEE OF THE CENTRAL ROCKIES IS IN THE PROCESS OF
   OCCLUDING.  INITIAL IMPULSE EMBEDDED WITHIN SOUTHERN BRANCH CLOSED
   LOW/TROUGH HAS ROTATED AROUND THE NORTHEASTERN PERIPHERY OF BROADER
   SCALE CIRCULATION...NOW CENTERED OVER SOUTHEASTERN COLORADO...WITH
   ANOTHER IMPULSE BEGINNING TO DIG TO THE LEE OF THE SOUTHERN ROCKIES.
   
   
   ...SOUTH CENTRAL PLAINS INTO LOWER MISSOURI VALLEY...
   IN THE EXIT REGION OF 70+ KT 500 MB JET STREAK ASSOCIATED WITH
   INITIAL IMPULSE...STORMS REMAIN CELLULAR ACROSS PARTS OF NORTH
   CENTRAL/NORTHEAST KANSAS...NEAR WARM FRONT EXTENDING EAST OF
   CYCLONE...NEAR/NORTH OF THE INTERSTATE 70 CORRIDOR.  EMBEDDED WITHIN
   DEEP LAYER SOUTHERLY CLOUD BEARING LAYER FLOW...CELLS HAVE BEEN
   QUICKLY LIFTING NORTH OF EAST-WEST ORIENTED FRONT...MINIMIZING
   TORNADO POTENTIAL TO THIS POINT.  HOWEVER...ACTIVITY ALSO APPEARS TO
   HAVE BEEN SLOW TO ROOT IN MOIST MIXED BOUNDARY LAYER WITH CAPE OF
   1000-1500 J/KG.  THIS INSTABILITY COULD INCREASE A BIT FURTHER LATE
   THIS AFTERNOON...AND TENDENCY SHOULD BE FOR ACTIVITY TO BECOME
   INCREASING SURFACE BASED.  LOW-LEVEL FLOW HAS WEAKENED IN WARM
   SECTOR ACROSS MUCH OF CENTRAL/EASTERN KANSAS INTO NORTHEAST
   OKLAHOMA...BUT LOW-LEVEL HODOGRAPHS AND AMBIENT ENVIRONMENT STILL
   APPEAR SUPPORTIVE OF TORNADOES...PARTICULARLY WHERE SURFACE WINDS
   ARE BACKED NEAR WARM FRONT.
   
   FARTHER SOUTH...WIND SHIFT...LOWER/MID TROPOSPHERIC COOLING
   ASSOCIATED WITH LEAD IMPULSE HAVE PROVIDED FORCING/FOCUS FOR
   EVOLVING SQUALL LINE NEAR/EAST OF THE INTERSTATE 35 CORRIDOR ACROSS
   CENTRAL OKLAHOMA INTO NORTH CENTRAL TEXAS.  THIS IS OCCURRING IN
   ADVANCE OF DRY LINE...IN ENVIRONMENT WITH STEEP MID LEVEL LAPSE
   RATES AND CAPE OF 1000-2000 J/KG.  LOW-LEVEL LAPSE RATES AHEAD OF
   ACTIVITY INTO THE LOWER MISSOURI VALLEY AND OZARKS HAVE NOT
   STEEPENED STRONGLY...BUT IN PEAK AFTERNOON HEATING...POTENTIAL FOR
   FURTHER INTENSIFICATION OF LINE IS LIKELY.  LARGE HAIL/DAMAGING WIND
   GUSTS APPEAR LIKELY WITH SQUALL LINE...ALONG WITH THE POTENTIAL FOR 
   ISOLATED TORNADOES EMBEDDED WITHIN AND AHEAD OF LINE.
   
   ...CENTRAL TEXAS THROUGH THE ARKLATEX/EXTREME SE OKLAHOMA...
   LOW-LEVEL HODOGRAPHS HAVE BECOME MAXIMIZED ACROSS PARTS OF CENTRAL
   INTO NORTHEAST TEXAS...WHERE SOUTHERLY LOW-LEVEL JET IN WARM SECTOR
   BOUNDARY LAYER...WITH SURFACE DEW POINTS NEAR 70F...REMAINS STRONG. 
   40+ KT 850 SOUTHERLY FLOW MAY STRENGTHEN FURTHER THROUGH EARLY
   EVENING...AS UPSTREAM IMPULSE CONTINUES SOUTHEAST OF THE ROCKIES
   INTO WEST TEXAS.  WEAK IMPULSE EMBEDDED WITHIN THE SUBTROPICAL
   STREAM MAY AID LARGE SCALE FORCING...AS IT LIFTS NORTHEAST OF THE
   LOWER RIO GRANDE VALLEY LATER THIS AFTERNOON AND EVENING. 
   AND...TORNADIC POTENTIAL...INCLUDING THE RISK FOR ISOLATED STRONG
   TORNADOES...APPEARS LIKELY TO BECOME HIGH WITH DISCRETE SUPERCELLS
   EXPECTED TO CONTINUE DEVELOPING AHEAD OF BROKEN SQUALL LINE
   ADVANCING THROUGH CENTRAL/EASTERN TEXAS.  
   
   **FOR MORE SPECIFIC INFORMATION CONCERNING ONGOING OR MORE IMMINENT
   SEVERE WEATHER THREATS...PLEASE REFER TO LATEST SPC MESOSCALE
   DISCUSSIONS/WATCHES.
   
   ..KERR.. 04/24/2007
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z