Jul 11, 2008 2000 UTC Day 1 Convective Outlook
Updated: Fri Jul 11 20:04:16 UTC 2008
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Categorical Graphic
20080711 2000 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20080711 2000 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20080711 2000 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20080711 2000 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 112000
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0300 PM CDT FRI JUL 11 2008
   
   VALID 112000Z - 121200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE UPPER
   MIDWEST INTO THE CENTRAL PLAINS...
   
   ...UPPER MIDWEST INTO CENTRAL PLAINS...
   WITH THE STRONG UPPER TROUGH CONTINUING TO SHIFT EASTWARD OVER THE
   NORTHERN HIGH PLAINS PER WATER VAPOR IMAGERY...MID AFTERNOON SURFACE
   ANALYSIS REFLECTS A CONTINUALLY DEEPENING 998 MB SURFACE LOW ACROSS
   THE FAR EASTERN DAKOTAS...WITH THE ASSOCIATED COLD FRONT EXTENDING
   SOUTH-SOUTHWESTWARD INTO EAST CENTRAL SD AND NORTHERN/WESTERN NEB.
   EASTWARD FROM THE SURFACE LOW...A ROUGHLY NORTHWEST-SOUTHEAST
   ORIENTED WARM FRONT CONTINUES TO LIFT NORTHWARD ACROSS
   NORTHWEST/CENTRAL MN AND NORTHWEST WI. A VERY WARM BOUNDARY LAYER IS
   IN PLACE WITHIN THE WARM SECTOR...WITH SURFACE DEWPOINTS IN THE
   UPPER 60S/LOWER 70S F CONTRIBUTING TO STRONG INSTABILITY WITH
   3000-4500 J/KG MLCAPE ACROSS THE FAR EASTERN DAKOTAS AND MUCH OF MN
   PER RUC-BASED OBJECTIVE ANALYSIS.
   
   A STRONG CAP IN PLACE PER MORNING 12Z RAOBS WILL LIKELY BE OVERCOME
   DURING THE NEXT SEVERAL HOURS IN VICINITY OF THE SYNOPTIC COLD FRONT
   /AND A SUBTLE PREFRONTAL TROUGH/ AS LARGE SCALE FORCING FOR ASCENT
   OVERSPREADS THE REGION. AS APPEARS TO ALREADY BE OCCURRING...INITIAL
   DEEP CONVECTIVE DEVELOPMENT APPEARS LIKELY INITIALLY ACROSS THE FAR
   EASTERN DAKOTAS INTO NORTHERN/CENTRAL MN. THE COMBINATION OF VERY
   FAVORABLE THERMODYNAMIC PARAMETERS AND EFFECTIVE SHEAR OF 40-50
   KNOTS SUGGEST SUPERCELL STRUCTURES ARE LIKELY...CAPABLE OF VERY
   LARGE HAIL AND DAMAGING WINDS. A RISK FOR TORNADOES APPEARS TO BE
   RELATIVELY MAXIMIZED NEAR THE SURFACE WARM FRONT ACROSS
   NORTHERN/CENTRAL MN /AND PERHAPS NORTHWEST WI/...WHERE BACKED
   SOUTHEASTERLY LOW LEVEL WINDS AND LOW LCL VALUES ARE IN PLACE.
   ACTIVITY WILL LIKELY SPREAD EASTWARD THROUGH THE EVENING...AFFECTING
   MUCH OF MN/WI THROUGH THE NIGHT...WITH POTENTIAL FOR UPSCALE
   DEVELOPMENT INTO ONE OR MORE SEVERE MCS/S LATER THIS EVENING.
   SUPERCELLS AND BOW/LEWP STRUCTURES ARE EXPECTED TO MAINTAIN A RISK
   OF DAMAGING WINDS AND HAIL ACROSS THE REGION WELL AFTER DARK.
   
   FARTHER SOUTH...TSTMS ARE FORECAST TO DEVELOP SOUTHWARD ALONG THE
   COLD FRONT INTO PARTS OF IA/NEB/KS LATER THIS AFTERNOON AND EARLY
   EVENING. VERTICAL SHEAR WILL BE SOMEWHAT WEAKER ALONG THIS PORTION
   OF THE COLD FRONT...BUT STEEP LOW-MID LEVEL LAPSE RATES AND DRY AIR
   ALOFT WILL PROMOTE DOWNDRAFT PRODUCTION WITH A THREAT OF DAMAGING
   WINDS IN STRONGER CELLS.
   
   ...AZ/CA...
   A VERY MOIST AIRMASS REMAINS IN PLACE OVER PARTS OF AZ/CA...WITH
   MORNING PSR/TUS SOUNDINGS AND GPS DATA SHOWING OVER 1.50 INCH PW
   VALUES. A COMBINATION OF EXTENSIVE CLOUDINESS AND THE EFFECTS OF
   YESTERDAYS STORMS WILL LIKELY SUPPRESS HEATING TODAY AND LIMIT
   DESTABILIZATION. THIS IS EXPECTED TO LESSEN THE OVERALL RISK OF
   SEVERE STORMS TODAY. NEVERTHELESS...LOCALLY DAMAGING THUNDERSTORM
   WINDS WILL BE POSSIBLE IN THOSE AREAS WHERE STRONG HEATING OCCURS.
   
   ..GUYER/KIS.. 07/11/2008
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z