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Jul-22-2003 0600 UTC Day 1 Convective Outlook
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   STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK 
   DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS.
   
   VALID 221200Z - 231200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
   20 S CRE 25 SSW ABY 30 SE MOB 25 W MSY 30 SE LCH 40 ENE HOU
   30 NNE DAL 15 SW TUL 15 ENE FYV MEM 40 N MSL 25 W BLF 20 WSW BGM
   25 NNE HUL.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 95 WSW TUS 35 S GBN
   35 NE BLH 60 NE DAG 35 WNW NID 45 NNE MER 55 NNE SAC 45 E EKA
   25 SSW EUG 25 ENE PDX 35 SSE EPH 30 W PUW 25 W S80 45 SE BKE
   75 E 4LW 15 SSE BAM 35 WSW ENV 25 WNW OGD 35 NNW EVW 35 NNE WEY
   20 ENE GTF 75 NE LWT 25 NW CDR 40 SSW IML 20 NNW SLN 50 NNE JLN
   25 NE VIH CMI 40 ESE MBL 75 NW ANJ ...CONT... 20 SSE PSX
   35 SSE JCT 65 WNW MRF.
   
   ...SYNOPSIS...
   COLD ADVECTION ASSOCIATED WITH MID-LEVEL JET STREAK DIVING SWD
   THROUGH THE PLAINS INTO THE LOWER MS VALLEY WILL EFFECTIVELY DEEPEN
   ERN CONUS TROUGH THROUGH THE PERIOD. DOWNSTREAM FROM THE TROUGH
   AXIS...A BELT OF MODERATELY STRONG MID-LEVEL WINDS /40-50KTS AT
   500MB/ ARE FORECAST FROM THE ERN TN VALLEY INTO THE NERN U.S.. 
   
   IN THE LOW-LEVELS...SURFACE FRONTAL SYSTEM WILL BE SLOW TO MOVE EWD
   THROUGH THE NERN U.S./DELMARVA REGION BENEATH INCREASINGLY
   MERIDIONAL MID-LEVEL FLOW PATTERN. FARTHER SW...SURFACE FRONT IS
   EXPECTED TO BE MORE PROGRESSIVE /POSSIBLY OWING TO CONVECTIVE
   OUTFLOW/ AND SHOULD EXTEND FROM THE ERN TN VALLEY THROUGH THE CNTRL
   GULF COAST INTO CNTRL TX BY LATE AFTERNOON/EARLY EVENING.
   
   ...NEW ENGLAND/DELMARVA SWD INTO THE SERN U.S...
   ONGOING TSTMS ASSOCIATED WITH SHORTWAVE TROUGH LIFTING NEWD ACROSS
   SERN ONTARIO/SRN QUEBEC WILL LIKELY LIMIT AIR MASS DESTABILIZATION
   AHEAD OF SURFACE FRONT OVER MUCH OF NEW ENGLAND. TO THE S...LATEST
   MODEL GUIDANCE SUGGESTS THAT SURFACE DEWPOINTS IN THE 70S AND
   DIABATIC HEATING WILL CONTRIBUTE TO MLCAPES OF 1000-2500 J/KG FROM
   SRN NEW ENGLAND SWD INTO THE DELMARVA BY AFTERNOON. HERE...ANY
   ONGOING TSTMS SHOULD INTENSIFY BY EARLY AFTERNOON AS THEY ENCOUNTER
   THIS MODERATELY UNSTABLE AIR MASS WITH ADDITIONAL DEVELOPMENT
   LIKELY IN LOW-LEVEL CONVERGENCE ZONE ALONG APPROACHING SURFACE
   FRONT AND/OR ANY EXISTING OUTFLOW BOUNDARIES.
   
   ETA FORECAST HODOGRAPHS INDICATE LARGELY UNIDIRECTIONAL WIND
   PROFILES WITH 30-40KT OF DEEP-LAYER SPEED SHEAR. ORIENTATION OF MID
   AND UPPER-LEVEL WINDS RELATIVE TO THE LOW-LEVEL BOUNDARY SUGGESTS
   A LINEAR MODE OF CONVECTION WITH DAMAGING WINDS BEING THE PRIMARY
   SEVERE WEATHER THREAT. THE EXCEPTION MAY BE OVER SRN NEW ENGLAND IF
   AIR MASS CAN SUFFICIENTLY DESTABILIZE. HERE...LOW-LEVEL SHEAR IS
   STRONGER OWING TO BACKED SURFACE WINDS WITH A CONDITIONAL THREAT OF
   SUPERCELLS AND ISOLATED TORNADOES. 
   
   FARTHER S ACROSS THE MIDDLE ATLANTIC INTO SERN U.S...THE STRONGER
   MID-LEVEL FLOW IS EXPECTED TO REMAIN ACROSS THE POST-FRONTAL AIR
   WITH RELATIVELY WEAK DEEP-LAYER SHEAR ACROSS THE WARM SECTOR.
   HOWEVER...MLCAPES OF 2000-3000 J/KG AND CONVERGENCE ALONG FRONTAL
   BOUNDARY MAY ALLOW A FEW CLUSTERS OF STRONG TSTMS TO DEVELOP WITH
   THE POTENTIAL FOR DAMAGING WINDS.
   
   ...GULF COAST/LOWER MS VALLEY EWD INTO THE SRN LOW PLAINS...
   CLUSTERS OF TSTMS WILL LIKELY BE ONGOING INITIALLY OVER PORTIONS OF
   ERN OK INTO AR ALONG FRONTAL BOUNDARY MOVING SWD INTO THE AREA. 
   GIVEN THE MODERATELY TO VERY UNSTABLE AIR MASS ALREADY IN PLACE
   ACROSS THIS REGION...SOME OF THE STRONGER STORMS WILL HAVE THE
   POTENTIAL TO PRODUCE LARGE HAIL AND DAMAGING WINDS THROUGH THE
   MORNING HOURS. 
   
   ADDITIONAL TSTMS ARE EXPECTED TO DEVELOP BY AFTERNOON ALONG SURFACE
   FRONT AND ANY OUTFLOW BOUNDARIES FROM NERN TX INTO MS/AL WHERE
   DEWPOINTS IN THE 70S AND DAYTIME HEATING SHOULD CONTRIBUTE TO
   MLCAPES OF 2500-3500 J/KG. HERE TOO...STRONG MID-LEVEL JET DIVING
   SWD THROUGH THE PLAINS WILL REMAIN ACROSS THE POST-FRONTAL AIR
   MASS...WITH GENERALLY LESS THAN 30KTS OF 0-6KM SHEAR FORECAST
   ACROSS THE FRONTAL ZONE INTO THE WARM SECTOR. STRENGTHENING/MERGING
   COLD POOLS MAY RESULT IN SWD ACCELERATING CONVECTIVE LINE SEGMENTS
   WITH THE POTENTIAL FOR PRIMARILY DAMAGING WINDS.
   
   ...AZ...
   PRESENCE OF MID-LEVEL MOISTURE ABOVE A DEEP AND WELL-MIXED BOUNDARY
   LAYER WILL CONTRIBUTE TO MLCAPES OF 1000 J/KG FROM SERN INTO CNTRL
   AZ. STRONG DAYTIME HEATING SHOULD ALLOW TSTMS TO DEVELOP LATER
   TODAY OVER THE HIGHER TERRAIN OF SERN AZ AND THE MOGOLLON RIM.
   ISOLATED DAMAGING DOWNBURSTS/HAIL MAY ACCOMPANY THE STRONGER STORMS
   AS THEY MOVE WWD/SWWD THIS EVENING INTO THE LOWER DESERTS.       
    
   ..MEAD/SCHNEIDER.. 07/22/03
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 1300Z
        
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