SPC AC 090045
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0745 PM CDT FRI AUG 08 2003
   
   VALID 090100Z - 091200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 55 W
   RRT 10 SSW MHE MHN CDR RAP REJ 4BQ BIL 3HT LWT 40 WSW GGW 60 N OLF
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM GCK 10
   E DDC P28 END OKC SPS 55 SSW CDS AMA 40 ENE TCC TAD LAA GCK
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 55 S MRF HOB 25 ENE
   LBB 35 SSW AMA 60 WSW CVS 45 NW TCS 55 SE SAD 65 SSW DMN ...CONT...
   CZZ DAG 55 E TPH TWF SUN BKE 70 SW PDT DLS OLM 20 NE BLI ...CONT...
   RRT BKX OMA FNB MHK POE 40 S BPT
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM PFN 10 SSW DHN SEM
   HSV HOP HUF 10 SSE AZO 35 NE MTC
   
   ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT FOR PARTS OF ERN MT AND
   THE DAKOTAS....
   
   ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT FROM PARTS OF SE CO
   INTO WRN OK/NW TX....
   
   ...NORTHERN PLAINS...
   CLOSED LOW REMAINS QUASI-STATIONARY OFF THE PACIFIC NORTHWEST COAST
   ...CUT-OFF FROM POLAR WESTERLIES...BUT SERIES OF SHORT WAVE TROUGHS 
   EMBEDDED WITHIN STRONGER BELT OF WESTERLIES TO ITS SOUTH AND EAST
   CONTINUE TO MIGRATE NORTHEASTWARD OUT OF THE LOWER LATITUDE PACIFIC
   INTO CREST OF SUBTROPICAL RIDGE OVER THE NORTHERN PLAINS.  ONE SUCH
   SHORT WAVE IS NOW PROGRESSING ACROSS SOUTHERN SASKATCHEWAN...AND HAS
   SUPPORTED INTENSE CLUSTER OF STORMS...WITH SOUTHERN FLANK AS FAR
   SOUTH AS THE MINOT ND AREA.  UPSTREAM SHORT WAVE TROUGH NOW
   PROGRESSING INTO WESTERN MONTANA IS SUPPORTING ONGOING CONVECTIVE
   CLUSTER NEAR/EAST OF LEWISTOWN MT...AND AS ASSOCIATED MID-LEVEL JET
   STREAK/FORCING FOR UPWARD VERTICAL MOTION SHIFT EASTWARD INTO THE
   NORTHERN PLAINS TONIGHT INCREASING CONVECTIVE DEVELOPMENT APPEARS
   LIKELY.  AT LEAST ONE LARGE CONVECTIVE CLUSTER MAY EVENTUALLY FORM
   TONIGHT...BECOMING FOCUSED IN VERY MOIST/UNSTABLE ENVIRONMENT
   NORTHEAST OF SURFACE LOW OVER WESTERN NORTH DAKOTA...BEFORE
   GRADUALLY SHIFTING EASTWARD ACROSS THE REMAINDER OF NORTH DAKOTA BY
   09/12Z.
   
   MEAN MIXED LAYER CAPE IN EXCESS OF 3000 J/KG ACROSS WESTERN NORTH
   DAKOTA WILL SUPPORT VIGOROUS UPDRAFTS WITH LARGE HAIL IN WEAK TO
   MODERATELY SHEARED ENVIRONMENT.  AS LARGER CONVECTIVE CLUSTER
   GRADUALLY FORMS...LOW RELATIVE HUMIDITIES IN LOWER/MID-LEVELS...
   EVIDENT IN 09/00Z SOUNDING FROM BISMARCK...INDICATE POTENTIAL FOR
   DOWNBURSTS AND DEVELOPMENT OF A SUBSTANTIAL SURFACE COLD POOL WITH
   ASSOCIATED DAMAGING WIND THREAT.
   
   ...CENTRAL PLAINS...
   LATEST OBSERVATIONAL DATA CONTINUE TO SUPPORT MODEL FORECASTS OF
   ANOTHER GROWING CLUSTER OF STORMS THIS EVENING ACROSS THE SOUTH
   CENTRAL HIGH PLAINS...ASSOCIATED WITH A WEAK WAVE MIGRATING AROUND
   SUBTROPICAL HIGH CENTER OVER NEW MEXICO.  ALTHOUGH THERMODYNAMIC
   PROFILES ARE WARM AND MEAN ENVIRONMENTAL FLOW WEAK...NOCTURNAL
   STRENGTHENING OF SOUTHERLY LOW-LEVEL JET IS PROGGED ACROSS THE
   TEXAS/OKLAHOMA PANHANDLE REGION...BENEATH 20 TO 30 KT NORTHERLY
   MID-LEVEL FLOW.  THIS MAY CONTRIBUTE TO SUFFICIENT SHEAR FOR AN
   ORGANIZED CONVECTIVE CLUSTER.  GIVEN PRESENCE OF DRY SUB CLOUD AIR
   ASSOCIATED WITH INVERTED-V TYPE PROFILES...EVAPORATIVE COOLING WILL
   ENHANCE POTENTIAL FOR DAMAGING DOWNBURSTS AND DEVELOPMENT OF A
   SURFACE COLD POOL/MESO HIGH.  NORTHWEST/SOUTHEAST ORIENTED LOW-LEVEL
   BAROCLINIC ZONE WILL PROVIDE FOCUS FOR CONVECTIVE ACTIVITY...WHICH
   MAY REACH THE RED RIVER VALLEY BY THE END OF THE FORECAST PERIOD.
   
   ...SOUTH TEXAS...
   STRONG/ISOLATED SEVERE STORMS ONGOING FROM SOUTHEAST INTO WEST
   CENTRAL TEXAS MAY BE ASSOCIATED WITH ANOTHER MID/HIGH-LEVEL SHORT
   WAVE TROUGH WHICH HAS WORKED ITS WAY AROUND THE EASTERN/SOUTHERN
   PERIPHERY OF THE SUBTROPICAL HIGH CENTER.  LOW-LEVEL FORCING FOR
   ACTIVITY IS WEAK...PARTICULARLY WITH ONSET OF RADIATIONAL SURFACE
   COOLING...AND ACTIVITY IS EXPECTED TO CONTINUE WEAKEN AS IT SPREADS
   INTO THE LOWER RIO GRANDE VALLEY.
   
   ..KERR.. 08/09/2003
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 0600Z