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 080100
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0800 PM CDT FRI OCT 07 2011
   
   VALID 080100Z - 081200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL PLAINS TO SRN
   HIGH PLAINS...
   
   ...SYNOPSIS...
   UPPER-AIR PATTERN WILL REMAIN CHARACTERIZED BY HIGH-AMPLITUDE
   RIDGING ASSOCIATED WITH 500-MB HIGH OVER INDIANA/OH...AND SYNOPTIC
   TROUGHING FROM CENTRAL CANADA TO NWRN MEX.  LATTER REGIME INCLUDES
   TWO PRIMARY MID-UPPER CYCLONES...
   1. OVER SRN MB...FCST TO CONTINUE MOVING NEWD OVERNIGHT TO NERN
   MB...AND
   2. DEVELOPING LOW OVER ERN AZ THAT WILL LIFT NNEWD ACROSS 4-CORNERS
   REGION TO WRN CO BY END OF PERIOD.
   
   AT 23Z...SFC FRONT RESULTING FROM MB CYCLONE WAS ANALYZED AS COLD
   FRONT OVER WRN MN...BECOMING QUASISTATIONARY OVER SERN
   SD...RETREATING SLOWLY NNWWD AS WARM FRONT OVER CENTRAL/SWRN
   NEB...NWRN KS AND INTO WEAK LOW OVER EXTREME S-CENTRAL CO BETWEEN
   LAA-ITR.  FRONT WAS DRAWN QUASISTATIONARY FROM LOW SSWWD ACROSS NERN
   NM THROUGH LOW W OF TCC...THEN TO S-CENTRAL NM.  NM PORTION OF FRONT
   SHOULD MOVE EWD AGAIN AS COLD FRONT OVERNIGHT AS SRN MID-UPPER WAVE
   EJECTS.  MEANWHILE LOW OVER ERN NM SHOULD MOVE/RE-FORM NNEWD ACROSS
   KS/CO BORDER REGION OVERNIGHT AND DEEPEN CONSIDERABLY WITH APCH OF
   TROUGH ALOFT...CONTRIBUTING TO CONTINUING NNWWD RETREAT OF FRONTAL
   ZONE OVER NEB.  23Z SFC MAP SHOWED DRYLINE AHEAD OF FRONT FROM NEAR
   EAR SSWWD TO NEAR GUY AND HOB.  DRYLINE SHOULD RETREAT WNWWD THROUGH
   REMAINDER EVENING...ESSENTIALLY MERGING WITH FRONT FROM W TX TO SWRN
   NEB THROUGH REMAINDER PERIOD.
   
   BKN BANDS OF TSTMS HAVE FORMED OVER WRN/NRN MN AND FROM NERN NEB TO
   SWRN KS...WITH WIDELY SCATTERED CONVECTION DEVELOPING IN BETWEEN
   THEM AND ALSO SWD ACROSS PORTIONS TX PANHANDLE.
   
   ...CENTRAL PLAINS TO SRN HIGH PLAINS...
   ELONGATED AND NARROW SWATH...REPRESENTED BY CATEGORICAL OUTLOOK
   AREA...CONTAINS GREATEST THREAT FOR SVR GUSTS...HAIL AND A FEW
   TORNADOES.  GREATEST JUXTAPOSITION OF LOW-LEVEL
   INSTABILITY...MOISTURE...LIFT AND SHEAR WILL PERSIST FOR LONGEST
   TIME OVER THIS SWATH.  BOTH DISCRETE AND LINE-EMBEDDED SUPERCELLS
   ARE POSSIBLE IN THIS STRONGLY MERIDIONAL DEEP-LAYER MEAN-WIND
   REGIME...THROUGHOUT WHICH EFFECTIVE SHEAR MAGNITUDES 50-60 KT WILL
   BE COMMON.  0-1 KM AGL SHEAR AND SRH SHOULD STRENGTHEN MARKEDLY
   THROUGH ABOUT 04Z IN STEP WITH INTENSIFICATION OF LLJ...COINCIDING
   WITH TIME WINDOW WHERE EFFECTIVELY SFC-BASED PARCELS STILL ARE
   COMMON.  REF WWS 861-862 AND RELATED MESOSCALE DISCUSSIONS FOR
   LATEST NEAR-TERM GUIDANCE ON CORRIDOR FROM TX PANHANDLE TO NERN NEB.
   
   TORNADO POTENTIAL SHOULD DIMINISH AFTER ABOUT 05Z...BOTH AS NEAR-SFC
   AIR MASS STABILIZES MORE AND AS CONVECTIVE MODES/INCREASING
   QUASI-LINEAR COVERAGE BECOME LESS FAVORABLE.
   LITTLE OR NO NET EWD SHIFT OF THREAT AREA IS EXPECTED...EXCEPT
   LOCALLY INVOF MOST DEVIANT RIGHT-MOVING CELLS.  INSTEAD...NWWD
   RETREAT OF MOIST SECTOR WILL EXPOSE CURRENTLY DRY AREAS OF WRN KS
   AND PANHANDLE TO CONVECTIVE/SVR POTENTIAL...THEREFORE EXISTING WWS
   AS WELL AS CATEGORICAL OUTLOOK LINE REMAIN W OF DRYLINE.  FARTHER
   S...ADDITIONAL DEVELOPMENT AND SUBSTANTIAL INCREASE IN CONVECTIVE
   COVERAGE INVOF FRONT/DRYLINE IS LIKELY THIS EVENING AND OVERNIGHT
   ACROSS W TX...POTENTIALLY AS FAR S AS PERMIAN BASIN.
   
   ...ERN SD TO NRN MN...
   RELATIVELY NARROW SPATIAL/TEMPORAL WINDOW FOR SVR HAIL/GUSTS EXISTS
   THIS EVENING WITH SD/MN CONVECTION...WHERE ISOLATED SVR HAIL/GUSTS
   APPEAR POSSIBLE FOR A FEW MORE HOURS.  ACTIVITY HAS FORMED AMIDST
   50-60 KT EFFECTIVE SHEAR MAGNITUDES...BUT STRONGLY PARALLEL
   COMPONENT OF FLOW ALOFT TO FORCING BOUNDARY SUITABLE FOR LINEAR
   CONVECTIVE ORGANIZATION.  COMBINATION OF MRGL MIDLEVEL LAPSE RATES
   AND DIABATIC SFC COOLING WILL RESULT IN DIMINISHING CAPE AND
   STRENGTHENING CINH AFTER ABOUT 03Z.
   
   ..EDWARDS.. 10/08/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z