Aug 4, 2011 0100 UTC Day 1 Convective Outlook
Updated: Thu Aug 4 00:58:08 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20110804 0100 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20110804 0100 UTC Day 1 Tornado Probabilities 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
20110804 0100 UTC Day 1 Damaging Wind Probabilities 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
20110804 0100 UTC Day 1 Large Hail Probabilities 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 040053
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0753 PM CDT WED AUG 03 2011
   
   VALID 040100Z - 041200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...SYNOPSIS...
   MIDDLE-UPPER LEVEL PATTERN REMAINS CHARACTERIZED BY INTENSE
   ANTICYCLONE CENTERED OVER ARKLATEX REGION...WITH TROUGHING ALONG E
   AND W COASTS.  IN BETWEEN...SEVERAL RELATIVELY LOW-AMPLITUDE
   SHORTWAVES PREVAIL.  THIS INCLUDES WEAK PERTURBATIONS NOW EVIDENT IN
   MOISTURE CHANNEL IMAGERY MOVING SEWD ACROSS SRN IL...AND NEWD OVER
   UT.  VIS AND COMPOSITE REFLECTIVITY ANIMATIONS INDICATE MCV DRIFTING
   NEWD ACROSS SERN NEB.
   
   AT SFC...23Z ANALYSIS SHOWED LOW OVER CENTRAL/NERN PA...WARM FRONT
   SWD OVER ERN VA THEN EWD OFFSHORE HAMPTON ROADS REGION...AND COLD
   FRONT SWWD ACROSS ERN KY TO NRN AR AND NERN OK.  FRONT EFFECTIVELY
   HAS BEEN SHUNTED FARTHER S THAN SYNOPTIC POSITION ACROSS CENTRAL/SRN
   OK BECAUSE OF AGGREGATE OUTFLOW.  FRONTAL ZONE GENERALLY W OF MS
   RIVER SHOULD BECOME QUASISTATIONARY THROUGH REMAINDER PERIOD...WHILE
   DRIFTING SEWD ACROSS TN VALLEY REGION AND CENTRAL/SRN APPALACHIANS.
   
   ...CENTRAL/SRN PLAINS TO SRN APPALACHIANS...
   WIDELY SCATTERED TO SCATTERED TSTMS REMAIN OVERALL...WITH SOMEWHAT
   MORE DENSE MESOSCALE CONCENTRATION OVER PORTIONS KS/OK. 
   PRE-STORM/BOUNDARY-LAYER AIR MASS ACROSS THIS REGION TRANSITIONS
   FROM HIGH-PW/LARGE-CAPE REGIME OVER KY/TN TO DEEPLY MIXED AND
   STRONGLY HEATED CHARACTER OVER SRN/CENTRAL PLAINS...EACH SUPPORTING
   LOCALLY STG-SVR DOWNDRAFTS IN REGIME OF WEAK DEEP-TROPOSPHERIC
   FLOW/SHEAR.  CONVECTIVE COVERAGE/INTENSITY GENERALLY SHOULD LESSEN
   THROUGH REMAINDER EVENING...DUE STABILIZING EFFECTS OF BOTH DIABATIC
   SFC COOLING AND INCREASING COVERAGE OF OUTFLOW AIR.
   
   ...WRN PORTIONS SD/NEB...
   WIDELY SCATTERED TO SCATTERED TSTMS ARE EVIDENT IN BAND FROM NEAR
   I-90 IN WRN SD SSWWD ACROSS CENTRAL/NRN NEB PANHANDLE AND ADJACENT
   PORTIONS EXTREME ERN WY.  SD ACTIVITY HAS PRODUCED CONSIDERABLE
   OUTFLOW ALREADY...WITH LOOSELY ORGANIZED COLD POOL EVIDENT OVER
   BADLANDS REGION OF SD AND MORE ISOLATED/LOCALIZED DOWNDRAFT THREAT
   FARTHER S AND SW.  RELATIVELY NARROW SPATIAL/TEMPORAL CORRIDOR
   REMAINS THROUGH WHICH STG/DAMAGING GUSTS ARE POSSIBLE FOR ANOTHER
   FEW HOURS.  MODIFIED RAOBS AND RUC SOUNDINGS SUGGEST THAT CURRENTLY
   OBSERVED SFC THETAE DECREASES WITH EWD EXTENT...COMBINED WITH SFC
   DIABATIC COOLING...WILL REDUCE GUST THREAT WITH TIME THIS EVENING.
   
   ...AZ...
   ISOLATED TO WIDELY SCATTERED TSTMS SHOULD PERSIST FOR ANOTHER FEW
   HOURS ACROSS THIS REGION...AMIDST PRE-STORM SFC TEMPS UPPER 90S TO
   LOW 100S F AND DEW POINTS 50S OVER LOWER ELEVATIONS.  00Z TUS RAOB
   AND MODIFIED MODEL SOUNDINGS EACH INDICATE POTENTIAL FOR ISOLATED
   STG-SVR GUSTS WITH MOST INTENSE DOWNDRAFTS...GIVEN DEEP/WELL-MIXED
   SUB CLOUD LAYERS AND POTENTIAL FOR EVAPORATIVE COOLING/ACCELERATION
   ON STORM SCALE.
   
   ..EDWARDS.. 08/04/2011
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z