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

   SPC AC 241208
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0708 AM CDT TUE APR 24 2007
   
   VALID 241300Z - 251200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS FROM KS/WRN MO SWD THRU OK/WRN
   AR TO CENTRAL TX...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK
   FROM THE CENTRAL AND SRN PLAINS EWD TO THE MID MS...LOWER OH
   VALLEYS....
   
   ...SEVERE THUNDERSTORMS EXPECTED TO BECOME WIDESPREAD ACROSS
   PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS BEGINNING THIS AFTERNOON
   AND CONTINUING TONIGHT...
   
   ...SYNOPSIS...
   VIGOROUS UPPER LOW SPINNING SLOWLY EWD VICINITY SRN CO/NM BORDER
   TODAY...INTO OK PANHANDLE TONIGHT. THE ASSOCIATED SURFACE LOW SERN
   CO MOVES TO NWRN OK BY 12Z WED. WARM FRONT EXTENDS FROM SURFACE LOW
   NEWD TO SRN NEB BORDER THEN EWD TO NRN MO. DRY LINE/PACIFIC FRONT
   CURRENTLY CROSSING TX PANHANDLE INTO WRN OK EXPECTED TO EXTEND N/S
   JUST W OF I-35 CORRIDOR SRN KS TO N TX BY LATE AFTERNOON. MODELS
   SUGGEST LITTLE OR JUST VERY SLOW FURTHER EWD MOVEMENT THIS EVENING.
   ABUNDANT GULF MOISTURE/INSTABILITY NOW PREVAILS E AND S OF THESE
   BOUNDARIES ACROSS THE PLAINS.
   
   ...CENTRAL/SRN PLAINS...
   GIVEN THE STRENGTH OF THE WIND FIELDS ROTATING ACROSS THE WARM
   SECTOR TODAY...COUPLED WITH THE AVAILABILITY OF
   INSTABILITY...CONFIDENCE IS HIGH THAT TORNADIC SUPERCELLS WILL
   OCCUR. HOWEVER THE UNCERTAINTY IS STILL WHERE THE GREATEST THREAT IS
   LOCATED THUS ATTM WILL CONTINUE WITH A RATHER LARGE MDT RISK.
   
   WATER VAPOR IMAGERY INDICATES A SPEED MAX CURRENTLY ROTATING NEWD
   AROUND UPR LOW ACROSS NERN NM WHICH SHOULD ENHANCE BOTH VERTICAL
   MOTION AND DEEP LAYER SHEAR BY EARLY AFTERNOON IN THE WARM SECTOR
   ACROSS WRN KS. THUNDERSTORMS EXPECTED TO INTENSIFY BY EARLY
   AFTERNOON IN THE LOW LEVEL CONVERGENCE BOTH VICINITY OF WARM FRONT
   NRN KS AND THE NRN EXTENSION OF DRY LINE/COLD FRONT WRN KS.  WITH
   MLCAPES AOA 2000 J/KG AND ENHANCED LOW LEVEL SHEAR...PARTICULARLY
   VICINITY OF BOUNDARIES...SUPERCELLS INCLUDING LARGE HAIL AND
   TORNADOES WILL BECOME MORE WIDESPREAD AS THE STORMS WORK EWD ACROSS
   KS THRU THE AFTERNOON.  POTENTIAL FOR STRONG TORNADOES ALSO SHOULD
   INCREASE THRU THE AFTERNOON.
   
   COLD FRONT HAS SURGED EWD INTO TX PANHANDLE AND THERE IS STILL
   UNCERTAINTY AS TO WHERE THE FRONT WILL BE PRIOR TO WHEN SURFACE
   INITIATION OCCURS THIS AFTERNOON.  BY MID AFTERNOON WITH MLCAPES
   ABOVE 2000 J/KG AND 50-60KT OF DEEP LAYER SHEAR...SUPERCELLS
   EXPECTED TO RAPIDLY DEVELOP FROM SRN KS SWD INTO NCENTRAL TX
   VICINITY OF DRY LINE.  CONFIDENCE IS LOW ON AMOUNT OF STORM
   COVERAGE...BUT ANY STORM SHOULD QUICKLY BECOME SUPERCELLULAR ALONG
   WITH TORNADO AND LARGE HAIL THREAT.  STORMS COULD THEN MOVE AWAY
   FROM DRY LINE ACROSS THE WARM SECTOR ERN OK/KS WHERE CONDITIONS WILL
   FAVOR POTENTIAL FOR LONG LIVED TORNADIC SUPERCELLS.
   
   MID/UPPER LEVEL JET STREAK NOTED ON WV IMAGERY TRACKING ENEWD FROM
   MEX COULD AID CONVECTIVE RELEASE ACROSS N TX BY THIS AFTERNOON WELL
   AHEAD OF THE DRY LINE.  AIR MASS THIS AREA CHARACTERIZED BY DEEPER
   MOISTURE AND POTENTIALLY MLCAPES AOA 2000 J/KG. LOW LEVEL SHEAR OF
   30KT AND DEEP LAYER SHEAR OF 50-60KT SUGGESTS ANY STORM THAT
   DEVELOPS WILL AGAIN QUICKLY BECOME A SUPERCELL WITH TORNADO AND
   LARGE HAIL POTENTIAL.  ENVIRONMENT WILL THEN SUPPORT LONG LIVED
   STORMS AS THEY TRACK NEWD ACROSS TX INTO SRN AR GIVEN THE
   MOIST/UNSTABLE WARM SECTOR. AGAIN STRONG TORNADOES WILL BE POSSIBLE.
   
   
   ADDITIONAL STORMS SHOULD EVENTUALLY FORM SWD ALONG/AHEAD OF DRY LINE
   BY LATE AFTERNOON SWD TO SCENTRAL TX WHERE AIRMASS WILL LIKELY BE
   VERY UNSTABLE WITH MLCAPES TO 3000 J/KG. VERY LARGE HAIL ALONG WITH
   TORNADO POTENTIAL WILL BE ASSOCIATED WITH ANY STORM.
   
   OVERNIGHT ALL MODELS HAVE A STRONG...CONSISTENT SIGNAL FOR THE
   DEVELOPMENT OF A LINER MCS ACROSS ERN TX WHICH IMPLIES ORGANIZED
   WIND DAMAGE POTENTIAL ALONG WITH THE TORNADO THREAT.  SEVERE
   THUNDERSTORMS LIKELY MUCH OF NIGHT SPREADING EWD TOWARD LOWER/MID MS
   VALLEY.
   
   ATTM WILL NOT UPGRADE ANY ONE OF THE AREAS DISCUSSED DUE TO
   CONFLICTING MODEL CONVECTIVE SIGNALS...BUT THE LARGE SCALE
   PARAMETERS SUGGEST THAT IT WILL BE A VERY ACTIVE SEVERE DAY AND
   LATER OUTLOOKS DURING THE DAY MAY BE ABLE TO BETTER IDENTIFY WHERE
   AN UPGRADE COULD BE SUPPORTED.
   
   ..HALES/JEWELL.. 04/24/2007
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z