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 261253
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0753 AM CDT SUN JUN 26 2011
   
   VALID 261300Z - 271200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF THE MID AND LWR MO
   VLYS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK
   AREA...FROM PARTS OF THE NRN PLNS E/SE INTO THE MID MS AND TN
   VLYS...
   
   ...SYNOPSIS...
   SEASONABLY STRONG W TO WSW FLOW WILL PREVAIL OVER THE NRN HALF OF
   THE NATION THIS PERIOD...ON POLEWARD SIDE OF ELONGATED RIDGE
   EXTENDING FROM THE SRN RCKYS TO LWR MS VLY.  STRONG...POSITIVE TILT
   SHORTWAVE TROUGH NOW OVER SK/WRN MT/ID WILL MOVE E INTO THE NRN HI
   PLNS THIS EVE...BEFORE CONTINUING E TO THE ERN DAKOTAS AND ASSUMING
   A MORE NEUTRAL TILT MON MORNING.  AT THE SAME TIME...A SERIES OF
   WEAKER DISTURBANCES IN BRANCH OF FLOW IMMEDIATELY TOPPING THE RIDGE
   WILL TRACK E ALONG ROUGHLY THE I-80 CORRIDOR FROM WY INTO NEB/IA.
   
   AT LWR LVLS...COLD FRONT PRECEDING THE SK/MT TROUGH SHOULD MOVE
   SLOWLY E/SE ACROSS THE DAKOTAS TODAY...BEFORE ACCELERATING E/SE INTO
   MN AND NEB TNGT/EARLY MON.  AHEAD OF THE FRONT...WRN PART OF
   BOUNDARY NOW EXTENDING FROM NRN KS TO KY LIKELY WILL ADVANCE NWD AS
   A WARM FRONT INTO ERN NEB AND SRN IA WHILE LEE LOW REMAINS STNRY IN
   KS.
   
   ...CNTRL/NRN PLNS TO MID MS VLY TODAY THROUGH MON...
   IN WAKE OF ELEVATED MORNING CONVECTION/STORMS...INCREASINGLY RICH
   MOISTURE /WITH SFC DEWPOINTS IN THE MID 60S TO LOW 70S F/ WILL
   SPREAD NWD FROM MO AND CNTRL/ERN KS INTO MUCH OF NEB AND SD AS SSELY
   LOW LVL FLOW STRENGTHENS OVER REGION AND WARM FRONT LIFTS N AHEAD OF
   AFOREMENTIONED UPR TROUGH.  AT THE SAME TIME...A DEEP EML WILL
   REMAIN PRESENT ALOFT AS WLY FLOW CONTINUES/STRENGTHENS ON NRN FRINGE
   OF UPR RIDGE.  COUPLED WITH STRONG SFC HEATING...SETUP SHOULD YIELD
   SBCAPE AOA 4000 J/KG FROM SRN SD AND CNTRL/ERN NEB SEWD INTO MO IN
   AREAS REMOVED FROM CONVECTIVE DEBRIS.
   
   BY MID/LATE AFTN...ASCENT ASSOCIATED WITH BOTH MAIN UPR TROUGH AND
   WITH AFOREMENTIONED WEAKER DISTURBANCES SHOULD SUPPORT SCTD TO
   NUMEROUS STORMS FROM NRN/ERN WY AND SRN MT...IN AREA NEAR/JUST N OF
   COLD FRONT...ENEWD INTO SD/SE ND AND WRN MN.  OTHER STORMS LIKELY
   WILL FORM IN AREA OF STRONGER LOW LVL WAA/MOISTURE TRANSPORT NEAR
   WARM FRONT AND/OR LEFTOVER OUTFLOW BOUNDARIES FROM CNTRL/ERN NEB
   INTO WRN IA.
   
   COMBINATION OF STRENGTHENING WSWLY MID/UPR LVL WSWLY FLOW ASSOCIATED
   WITH APPROACHING TROUGH WILL COINCIDE WITH MODERATE TO STRONG
   DESTABILIZATION...SUPPORTING NUMEROUS SUPERCELL CLUSTERS CAPABLE OF
   LARGE HAIL...DMGG WIND...AND TORNADOES /ONE OR TWO OF WHICH COULD BE
   STRONG/.  THIS THREAT APPEARS GREATEST LATE THIS AFTN INTO EARLY
   TNGT OVER PARTS OF SD AND NEB.
   
   CONTINUED EWD ADVANCE OF UPR TROUGH...LARGE RESERVOIR OF
   MOIST/UNSTABLE AIR OVER THE CNTRL PLNS/OZARKS/MID MS VLY...AND
   SUBSTANTIAL DIFFLUENCE BETWEEN AMPLIFYING UPR TROUGH AND BRANCH OF
   WLY FLOW IMMEDIATELY TOPPING SRN PLNS RIDGE STRONGLY SUGGEST THAT
   THE NEB/IA STORMS WILL EVOLVE INTO A LARGE MCS.  PARTS OF THIS
   SYSTEM LIKELY WILL DEVELOP FORWARD-PROPAGATING/BOWING SEGMENTS THAT
   PERSIST/REDEVELOP THROUGH EARLY MON...EXTENDING A THREAT FOR DMGG
   WIND/SVR HAIL E/SE INTO NRN MO AND PARTS OF IL/IND.  SEPARATE
   CONVECTIVE CLUSTERS/BANDS LIKELY WILL CONTINUE E ACROSS MN DURING
   THE OVERNIGHT...ALTHOUGH SVR THREAT WITH THESE SHOULD DIMINISH AS
   THE STORMS OUTRUN LOW LVL INSTABILITY.
   
   ...TN VLY/SERN STATES THIS AFTN...
   OUTFLOW BOUNDARY AND/OR WEAK CIRCULATIONS ASSOCIATED WITH OVERNIGHT
   MCS IN THE LWR OH VLY MAY SERVE TO FOCUS DIURNALLY ENHANCED STORM
   DEVELOPMENT OVER PARTS OF THE TN VLY/SRN APPALACHIANS TODAY.  AREA
   WILL LIE BENEATH ERN FRINGE OF EML...WITH SBCAPE OF 2000 J/KG
   EXPECTED BY AFTN.  COUPLED WITH 20+ KT NWLY MID LVL FLOW ON ERN SIDE
   OF UPR RIDGE...SETUP MAY SUPPORT A FEW SMALL MULTICELL CLUSTERS WITH
   ISOLD DMGG WIND AND/OR SVR HAIL.
   
   ...SRN PLNS LATE THIS AFTN/EVE...
   INCREASED POST-DRY LINE WLY FLOW ASSOCIATED WITH DISTURBANCES
   CROSSING THE CNTRL/NRN PLNS MAY SUFFICIENTLY ENHANCE CONVERGENCE
   ALONG THE DRY LINE TO YIELD ISOLD TO WDLY SCTD STORMS OVER ERN
   PORTIONS OF THE TX PANHANDLE/WRN OK LATE THIS AFTN/EVE.  SHOULD SUCH
   STORMS FORM...THERMODYNAMIC ENVIRONMENT WILL BE SUPPORTIVE OF
   LOCALLY DMGG WIND AND/OR SVR HAIL.
   
   ..CORFIDI/GRAMS.. 06/26/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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