Categorical Graphic
Probabilistic Tornado Graphic
Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Probabilistic Damaging Wind Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Probabilistic Large Hail Graphic
Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.

   SPC AC 281309
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0709 AM CST TUE FEB 28 2012
   
   VALID 281300Z - 291200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE SRN AND CNTRL
   PLNS E/NE INTO THE OZARKS AND LWR OH/LWR TN VLYS...
   
   ...SYNOPSIS...
   WITH THE SYSTEM OFF THE BC CST LIKELY TO AMPLIFY SE TOWARD THE
   PACIFIC NW THIS PERIOD...EXPECT STRONG SHORTWAVE TROUGH NOW OVER THE
   GRT BASIN WILL ACCELERATE ENE TO THE CNTRL HI PLNS THIS EVE...BEFORE
   CONTINUING NE TO EVOLVE INTO A COMPACT CLOSED OVER THE UPR MS VLY
   EARLY WED.  POTENT VORT MAX WITH THE GRT BASIN TROUGH WILL BE
   ACCOMPANIED BY A 90-100 KT 500 MB JET STREAK AS IT CROSSES THE CNTRL
   AND SRN PLNS TNGT.  
   
   AT THE SFC...LEE LOW SHOULD STRENGTHEN THROUGH THE DAY OVER NE
   CO...WITH THE LOW THEN TRACKING NE TO NEAR SIOUX FALLS BY MIDNIGHT
   ...AND INTO SRN MN EARLY WED.  LOW LVL MOISTURE WILL CONTINUE TO
   SPREAD NWD AHEAD OF ASSOCIATED PACIFIC COLD FRONT THAT ATTM TRAILS
   SSW THROUGH CNTRL NM...AND AHEAD OF LEE TROUGH/DRY LINE NOW ENTERING
   FAR W TX.  FARTHER E...CURRENT SFC DATA SHOW SHALLOW WARM FRONT
   BEGINNING TO FORM FROM N CNTRL TX ESE TO NRN LA.  THIS FEATURE
   SHOULD MOVE/REDEVELOP NNEWD THROUGH THE PERIOD...WITH SFC DEWPOINTS
   IN THE LOW 60S EXPECTED AS FAR NE AS SERN MO AND THE LWR OH VLY BY
   EARLY WED.
   
   THE COMBINATION OF INCREASING MOISTURE WITH STRENGTHENING SHEAR AND
   ASCENT WILL RESULT IN AN INCREASING RISK FOR SVR TSTMS FROM PARTS OF
   THE SRN PLNS NEWD INTO PARTS OF THE CNTRL PLNS...THE OZARKS...AND
   THE LWR OH/TN VLYS BEGINNING LATER TODAY AND CONTINUING THROUGH 12Z
   WED.
     
   ...SRN PLNS INTO OZARKS AND LWR OH/TN VLYS TODAY/TNGT...
   EML ASSOCIATED WITH AFOREMENTIONED JET STREAK SHOULD KEEP
   ENVIRONMENT CAPPED THROUGH MUCH OF THE DAY OVER WRN PARTS OF THE
   CNTRL/SRN PLNS.  HOWEVER...COMBINATION OF LOW LVL UPLIFT ALONG
   MERGING COLD FRONT/DRY LINE...SFC HEATING...AND 30-60 M HEIGHT FALLS
   ON SRN FRINGE OF EJECTING UPR TROUGH SHOULD SUPPORT ISOLD TO WDLY
   SCTD TSTMS FROM NW TX NNEWD INTO WRN OK AND CNTRL KS BY EARLY EVE. 
   OTHER STORMS SHOULD FORM A BIT LATER THIS EVE FARTHER E AND
   NE...ALONG WRN FRINGE OF STRENGTHENING SSWLY LLJ/MOISTURE AXIS FROM
   N CNTRL/NE TX THROUGH THE ERN THIRD OF OK INTO PARTS OF AR AND
   SRN/CNTRL MO.  DEVELOPMENT IN THE OZARKS WILL BE FOSTERED BY UPLIFT
   ALONG WARM FRONT.
   
   STRONGLY SHEARED ENVIRONMENT ASSOCIATED WITH THE STRENGTHENING DEEP
   WIND FIELD WILL BE SUPPORTIVE OF STRONG SUPERCELLS GIVEN 60-90 KT
   SWLY 0-6 KM SHEAR. INITIALLY...STRONG TO SVR STORMS WILL BE POSSIBLE
   ALONG THE COLD FRONT/DRYLINE...WHERE HAIL AND PERHAPS A TORNADO OR
   TWO MAY OCCUR.  HOWEVER...THE GREATER SVR THREAT SHOULD DEVELOP TNGT
   THROUGH EARLY WED AS STORM COVERAGE RAPIDLY INCREASES OVER ERN
   PORTIONS OF THE SRN PLAINS INTO AR/SRN MO INVOF THE LLJ.  LOW LVL
   SHEAR WILL BE MAXIMIZED ALONG WARM FRONT...WHERE AN ELONGATED...
   LOOSELY ORGANIZED CLUSTER OF SUPERCELLS MAY EVOLVE. THIS ACTIVITY
   MAY POSE A SIZABLE RISK FOR TORNADOES...IN ADDITION TO DMGG
   WIND...GIVEN 0-1 KM SRH ON THE ORDER OF 300-400 M2/S2...AND MLCAPE
   APPROACHING 1000 J/KG.  THIS THREAT LIKELY WILL MOVE/DEVELOP ENE
   INTO THE LWR OH AND TN VLYS EARLY WED AS THE LLJ JET DEVELOPS
   RAPIDLY NEWD. 
   
   ...CNTRL PLNS/LWR MO VLY LATE THIS AFTN/EARLY TNGT...
   TSTMS SHOULD FORM OVER PARTS OF NEB AND KS THIS AFTN IN EXIT REGION
   OF JET STREAK ASSOCIATED WITH POTENT UPR VORT.  THE STORMS SHOULD
   MOVE NE INTO ERN NEB/WRN IA BY EARLY EVE.  WITH THE ENVIRONMENT
   LIKELY TO EXHIBIT SBCAPE AROUND 1000 J/KG...STEEP MID LVL LAPSE
   RATES...AND 75 KT SWLY DEEP SHEAR...SETUP COULD SUPPORT A POCKET OF
   SUPERCELLS CAPABLE OF LARGE HAIL AND PERHAPS A TORNADO.  THE STORMS
   SHOULD WEAKEN BY LATE EVE.
   
   ..CORFIDI/BOTHWELL/PETERS.. 02/28/2012
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z