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

   SPC AC 231536
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1036 AM CDT MON MAR 23 2009
   
   VALID 231630Z - 241200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF CNTRL AND ERN KS
   AND NRN OK...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA
   FROM N TX INTO MID MO AND MID MS VLYS...
   
   OVERALL SCENARIO DISCUSSED IN PRIOR/13Z/ DY1 OUTLOOK IS ON TRACK. 
   INTENSE UPPER VORT/LOW BECOMING VERTICAL WITH STRONG SURFACE LOW
   SWRN NEB AND TRACKS NEWD INTO SERN SD BY 12Z TUE. 50-60KT LLJ
   CONTINUES TO STREAM A MOIST AND INCREASINGLY UNSTABLE AIRMASS NWD
   AHEAD OF THE COLD FRONT DRY LINE WHICH EXTENDS SWD FROM LOW CENTER
   THRU WRN KS INTO TX PANHANDLE ATTM.
   
   STRONG ASCENT AND MID LEVEL COOLING WILL QUICKLY ERODE THE CINH OVER
   NEB INTO SRN SD AHEAD OF LOW WITH SEVERE THUNDERSTORMS DEVELOPING BY
   EARLY AFTERNOON.  FURTHER S INTO KS AND OK SEVERE THUNDERSTORMS WILL
   GRADUALLY FORM LATER THIS AFTERNOON AS HEATING AND ASCENT REMOVE THE
   CURRENT SUBSTANTIAL INHIBITION.
   
   ...S CNTRL/ERN SD SWD INTO CNTRL/ERN NEB AND N CNTRL KS TODAY...
   
   REF MCD 238
   
   ALTHOUGH BOUNDARY LAYER MOISTURE WILL REMAIN COMPARATIVELY LIMITED
   /SFC DEWPOINTS IN THE LOW 50S/...WITH 500 MB TEMPS AROUND MINUS 20
   C...MODEST SFC HEATING SHOULD BOOST SBCAPE TO AOA 500 J/KG.
   COMBINATION OF DESTABILIZATION AND INCREASING ASCENT WILL SUPPORT
   TSTM DEVELOPMENT ALONG COLD FRONT/OCCLUSION BY 18Z THROUGH LATE THIS
   AFTN FROM S CNTRL SD ACROSS CNTRL NEB INTO N CNTRL KS.
   
   DEEP SHEAR WILL BE STRONG /40-50 KTS/ THROUGHOUT REGION...ALTHOUGH
   WITH A SUBSTANTIAL COMPONENT ORIENTED PARALLEL TO FRONT IN SD AND
   NEB.  OVERALL SETUP SHOULD YIELD A FEW SUSTAINED STORMS WITH A
   THREAT FOR SVR HAIL/WIND.  ASSUMING THE PRESENCE OF SUSTAINED
   UPDRAFTS...BACKED LOW-LVL FLOW NE OF SFC LOW IN NRN NEB AND SRN SD
   ALSO WILL BE FAVORABLE FOR LOW LVL STORM ROTATION/TORNADOES
   ...BEFORE FRONT AND DEEP ASCENT OUTRUN LOW LVL MOIST AXIS LATE IN
   THE DAY. VERTICAL SHEAR PROFILES WILL BE MORE CONDUCIVE FOR TORNADIC
   SUPERCELLS WITH SWD EXTENT AND THE TORNADO PROBABILITIES HAVE BEEN
   INCREASED ACCORDINGLY NWD INTO SERN NEB.
   
   ..CNTRL/ERN KS SSW INTO MUCH OF OK/NW TX LATE TODAY/TONIGHT...
   DEEP FORCING FOR ASCENT AND MID LVL COOLING WILL REMAIN WEAK FROM
   CNTRL KS SW ACROSS OK AND NW TX TODAY AS LEAD SPEED MAX/UPR VORT
   LIFT NE INTO NEB/SD.  COUPLED WITH RELATIVELY LIMITED BOUNDARY LAYER
   MOISTURE AND SUBSTANTIAL EML CAP ON S SIDE OF UPR JET...EXPECT
   LITTLE IF ANY TSTM DEVELOPMENT TIL LATE IN THE DAY OVER OK AND NW
   TX.  SCTD STORMS MAY...HOWEVER...CONTINUE TO DEVELOP SLOWLY SWD
   ALONG FRONT IN KS.
   
   BY EARLY EVE...ASCENT WITH UPSTREAM JET DISTURBANCE SHOULD BEGIN TO
   OVERSPREAD THE SRN PLNS AS COLD FRONT OVERTAKES PRE-FRONTAL
   TROUGH/DRY LINE.  COMBINATION OF STRENGTHENING ASCENT WITH SLOWLY
   INCREASING BOUNDARY LAYER MOISTURE /SFC DEWPOINTS IN THE UPR 50S TO
   NEAR 60 F/ MAY SUPPORT INCREASED STORM COVERAGE/STRENGTH ALONG THE
   FRONT IN KS...AND DEVELOPMENT OF OTHER STORMS SW ALONG FRONT OR DRY
   LINE INTO OK.
   
   50+ KT DEEP SHEAR OVER REGION WILL BE ORIENTED AT A CONSIDERABLE
   ANGLE TO THE FRONT.  GIVEN SUSTAINED UPDRAFTS...THIS SHOULD ALLOW
   FOR THE DEVELOPMENT OF ELONGATED SUPERCELL STRUCTURES WITH A GOOD
   THREAT FOR LARGE HAIL AND HIGH WIND.  IN ADDITION...35-40 KT 0-1 KM
   SHEAR WITH A SUBSTANTIAL DIRECTIONAL COMPONENT /ASSOCIATED WITH 60KT
   SSWLY LOW LVL JET/...SUGGESTS POTENTIAL FOR STRONG TORNADOES
   ...IF SUSTAINED SEMI-DISCRETE STORMS DO INDEED FORM.
   
   ..HALES/JEWELL.. 03/23/2009
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z