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 070557
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1257 AM CDT FRI OCT 07 2011
   
   VALID 071200Z - 081200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS TX PANHANDLE TO NERN
   NEB...
   
   ...SYNOPSIS...
   IN MID-UPPER LEVELS...SYNOPTIC PATTERN WILL REMAIN HIGH-AMPLITUDE IN
   PHASE SHAPE...DOMINATED BY RIDGING FROM SRN APPALACHIANS TO HUDSON
   BAY AND TROUGHING FROM SWRN CONUS NNEWD OVER NRN HIGH PLAINS. 
   500-MB LOW CURRENTLY DEVELOPING OVER SRN WY IS FCST TO EJECT NEWD
   THIS PERIOD FROM NERN WY TO NERN MB.  MEANWHILE...SECOND SHORTWAVE
   TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER CENTRAL/SRN
   CA -- IS FCST TO PIVOT CYCLONICALLY OVER AZ EARLY IN PERIOD THEN
   NEWD TO NRN NM/SRN CO REGION AS 500-MB CLOSED CYCLONE BY 08/12Z.
   
   AT SFC...COLD FRONT NOW EVIDENT OVER WRN PORTIONS SD/NEB/KS AND SERN
   CO IS EXPECTED TO MOVE EWD ACROSS DAKOTAS AND OVER NWRN MN.  FRONT
   SHOULD DECELERATE THIS PERIOD OVER CENTRAL/SRN PLAINS...BENEATH
   NEARLY PARALLEL MID-UPPER WINDS.  APCH OF SRN SHORTWAVE TROUGH
   SHOULD INDUCE WAVE-LOW DEVELOPMENT ALONG FRONT DURING 08/06Z-08/12Z
   TIME FRAME OVER CORRIDOR BETWEEN NERN NM AND  W-CENTRAL KS.  MORE
   SPECIFIC POSITION OF ANY FRONTAL-WAVE CYCLONE FORMATION MAY BE
   MODULATED BY CONVECTIVE TRENDS INVOF THAT SEGMENT OF FRONT.  BY LATE
   THIS AFTERNOON...DRYLINE AND FRONT ESSENTIALLY WILL BE MERGED N OF
   PERMIAN BASIN REGION...WHERE DRYLINE EXTENDS SWD ACROSS BIG BEND
   AREA.
   
   ...SRN HIGH PLAINS TO MN...
   MULTIPLE EPISODES OF TSTM FORMATION ARE EXPECTED INVOF FRONT FROM
   LATE AFTERNOON THROUGH OVERNIGHT HOURS.  15% WIND/SLGT RISK AREA
   REPRESENTS MOST FAVORABLE JUXTAPOSITION OF EXPECTED BOUNDARY-LAYER
   THETAE...BUOYANCY...DEEP-LAYER SHEAR AND PROBABILITY OF SFC-BASED
   TSTMS.  FAVORABLE LOW-LEVEL HODOGRAPHS ARE FCST IN THIS
   CORRIDOR...ESPECIALLY IN 00-04Z TIME FRAME WHEN STRENGTHENING LLJ
   ENLARGES 0-1 KM AGL SHEAR MAGNITUDES.  LIMITING FACTORS INCLUDE LACK
   OF MID-UPPER SUPPORT BETWEEN SHORTWAVE TROUGHS...LACK OF MORE ROBUST
   MOISTURE AND LAPSE RATES...AND CONCERNS ABOUT STORM MODE.  WITH MEAN
   WIND VECTOR ALIGNED NEARLY PARALLEL TO ZONE OF LOW-LEVEL
   LIFT...CONVECTIVE MODES MAY BECOME MESSY BEFORE HODOGRAPHS MOST
   STRONGLY FAVOR SUPERCELLS...WITH CLUSTERS AND LINE SEGMENTS
   POSSIBLE.  GIVEN THAT FACTOR...AND LACK OF LARGER LAPSE RATES
   ALOFT...HAIL POTENTIAL APPEARS TO BE LOWER AND MORE CONDITIONAL THAN
   CONVECTIVE WIND THREAT...AND TORNADO THREAT IS MRGL BUT NONZERO.  
   
   OFF NRN END OF SLGT RISK AREA...SVR PROBABILITIES WILL DIMINISH WITH
   NNEWD EXTENT FROM NERN NEB ACROSS MN BECAUSE OF RELATIVELY WEAK
   INSTABILITY...BOTH SFC AND ALOFT. THIS WILL LEAD TO CAPE BEING MRGL
   AT MOST...LIMITING SVR POTENTIAL DESPITE FAVORABLE DEEP-LAYER SHEAR.
   OFF SRN END OF SLGT RISK AREA...DIABATIC HEATING AND LOW-LEVEL
   MOISTURE SHOULD BE FAVORABLE THIS AFTERNOON FROM TX SOUTH-PLAINS
   REGION SWD ACROSS PERMIAN BASIN...AHEAD OF FRONT/DRYLINE. 
   HOWEVER...TSTM COVERAGE BECOMES MORE UNCERTAIN WITH SWD EXTENT.
   
   ..EDWARDS/SMITH.. 10/07/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z