SPC AC 071945
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0245 PM CDT SAT MAY 07 2005
   
   VALID 072000Z - 081200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 45 SSW
   P07 35 SW INK LBB 15 NE LBL 25 ENE GLD 35 NNW GLD 25 WNW LIC 25 ESE
   DEN 20 SE FCL 25 NE CDR 45 E 81V 35 ESE MLS 40 NW GDV 60 NNW ISN
   ...CONT... RRT MCW DSM PNC 30 ESE FSI 45 SE BWD 35 N HDO 65 SSE DRT.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 WSW
   MRB 10 S LYH 40 SSE PSK 20 ENE TRI 25 SSE JKL 50 WNW LUK 30 ESE MIE
   25 SSW MFD 20 S PIT 30 WSW MRB.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 10 E ILM 15 NW HKY 35
   NW HSS 30 ENE CKV 25 SSE CGI 25 WSW POF 25 S HOT 35 SSW GGG 55 N VCT
   50 WNW MFE ...CONT... 65 S MRF 50 ESE GDP 50 S CVS 20 WSW DHT 35 NNE
   CAO 15 WNW LAA 10 SW PUB 30 N ALS 25 NNW ABQ 40 ESE SOW 20 SSE INW
   35 SSW GCN 65 N IGM 35 WSW P38 60 S EKO 45 WSW TWF 35 E BOI 65 W 27U
   25 N S80 40 WSW GEG 30 N 4OM ...CONT... 75 NNW ANJ 55 E ESC 25 SSW
   MBL 10 N AZO 30 W TOL 30 SSW BUF 45 ENE BFD 20 E CXY 25 E ORF.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN PLAINS/UPPER MS
   VALLEY SWD INTO TX...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE UPPER OH
   VALLEY INTO CNTRL APPALACHIANS...
   
   ...NRN/CNTRL PLAINS INTO MID/UPPER MS VALLEY...
   EARLY AFTERNOON MESOANALYSIS SHOWED OCCLUDED SURFACE LOW OVER SERN
   MT WITH ATTENDANT WARM FRONT EXTENDING SEWD THROUGH SERN SD/CNTRL IA
   AND INTO THE OH VALLEY. MEANWHILE...PACIFIC COLD FRONT WAS BEGINNING
   TO ADVANCE EWD THROUGH PORTIONS OF WRN NEB WITH DRYLINE EXTENDING
   SWD FROM INTERSECTION WITH COLD FRONT OVER SWRN NEB ACROSS WRN KS /E
   OF GLD TO GCK/.
   
   SEVERE TSTMS ARE EXPECTED TO BECOME INCREASINGLY WIDESPREAD ALONG
   COLD FRONT NWD TO VICINITY OF WARM FRONT THIS AFTERNOON INTO EVENING
   AS LARGE-SCALE FORCING ASSOCIATED WITH SHORTWAVE TROUGH LIFTING OUT
   OF THE CNTRL HIGH PLAINS OVERSPREADS WARM SECTOR. 18Z LBF SOUNDING
   SHOWED THE PRESENCE OF STEEP LOW TO MID-LEVEL LAPSE RATES AND A
   POTENTIALLY UNSTABLE AIR MASS. CONTINUED DIABATIC HEATING SHOULD
   ALLOW FOR ADDITIONAL DESTABILIZATION/CAP REMOVAL WITH MLCAPES
   INCREASING TO 1000-2000 J/KG. DESPITE LARGELY UNIDIRECTIONAL WINDS
   WITH HEIGHT...55-65KT MID-LEVEL JET STREAK ACCOMPANYING SHORTWAVE
   TROUGH FROM ERN CO NNEWD INTO N-CNTRL NEB WILL PROVIDE SUFFICIENT
   VERTICAL SPEED SHEAR FOR SUPERCELLS CAPABLE OF VERY LARGE
   HAIL...DAMAGING WINDS AND POSSIBLY A COUPLE OF TORNADOES. STORM MODE
   WILL LIKELY EVOLVE TO MORE LINEAR WITH TIME AS ACTIVITY SPREADS NEWD
   THROUGH THE MO RIVER VALLEY.
   
   WEAKER LEAD SHORTWAVE TROUGH LIFTING NEWD THROUGH CNTRL KS ATTM MAY
   SERVE TO FOCUS ADDITIONAL DOWNSTREAM DEVELOPMENT THIS AFTERNOON S OF
   WARM FRONT OVER ERN NEB INTO IA. WHILE DEEP-LAYER SHEAR IS
   COMPARATIVELY WEAKER THAN POINTS W...STEEP LAPSE RATES AND
   DEVELOPING MODERATE INSTABILITY WOULD SUPPORT STRONG UPDRAFTS
   CAPABLE OF LARGE HAIL AND DAMAGING WINDS.
   
   ...KS/OK/TX DRYLINE...
   SURFACE OBSERVATIONS AND VISIBLE SATELLITE IMAGERY SHOW DRYLINE
   BECOMING BETTER DEFINED THIS AFTERNOON FROM W OF HLC AND DDC TO THE
   ERN EDGE OF THE CAPROCK IN THE TX PNHDL TO NEAR P07. TEMPERATURES
   WARMING THROUGH THE 70S COUPLED WITH DEWPOINTS IN THE 50S TO LOWER
   60S AND STEEP LOW/MID-LEVEL LAPSE RATES ARE CONTRIBUTING TO A
   MODERATELY UNSTABLE AIR MASS ALONG/E OF THIS FEATURE WITH MLCAPES OF
   1000-1500 J/KG. ADDITIONAL DESTABILIZATION IS EXPECTED THIS
   AFTERNOON INTO EVENING WITH MLCAPES APPROACHING 2000 J/KG AND A WEAK
   CAP. LATEST NAM GUIDANCE REMAINS CONSISTENT IN DEVELOPING A WEAK
   PRECIPITATION SIGNAL ALONG DRYLINE BY LATE AFTERNOON/EARLY EVENING.
   
   18Z AMA SOUNDING SHOWED 50 KT SWLY WINDS AS LOW AS 4.5 KM AGL AND
   GIVEN SSELY SURFACE WINDS CURRENTLY BEING OBSERVED E OF
   DRYLINE...VERTICAL SHEAR WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS
   WITH VERY LARGE HAIL BEING PRIMARY SEVERE WEATHER THREAT. DIURNAL
   BACKING OF BOUNDARY-LAYER FLOW NEAR OR AFTER 08/00Z MAY ENHANCE
   LOW-LEVEL SHEAR SUFFICIENTLY TO SUPPORT AN ISOLATED TORNADO WITH ANY
   ONGOING SUPERCELLS.
   
   WHILE MUCH OF DRYLINE ACTIVITY WILL BE DIURNAL IN NATURE...INCREASED
   FORCING FOR ASCENT AHEAD OF SHORTWAVE TROUGH OVER SRN AZ/NWRN MEXICO
   WILL LIKELY LEAD TO AN INCREASE IN TSTM COVERAGE TONIGHT FROM
   PORTIONS OF SWRN TX EWD INTO THE CONCHO VALLEY AND W-CNTRL TX. THE
   STRONGEST STORMS WILL BE CAPABLE OF MAINLY LARGE HAIL AND DAMAGING
   WINDS.
   
   ...UPPER OH VALLEY INTO CNTRL APPALACHIANS...
   TSTMS ARE BECOMING MORE NUMEROUS THIS AFTERNOON OVER SERN OH INTO WV
   AHEAD OF VIGOROUS SHORTWAVE TROUGH DIVING SEWD ACROSS REGION.
   DAYTIME HEATING AHEAD OF WEAK SURFACE LOW AND ATTENDANT COLD FRONT
   HAVE ALLOWED LOW-LEVEL LAPSE RATES TO STEEPEN...EFFECTIVELY
   CONTRIBUTING TO SBCAPES OF 250-500 J/KG. RATHER STRONG
   UNIDIRECTIONAL NWLY FLOW OBSERVED ON LOCAL VWPS COUPLED WITH THE
   STEEP LAPSE RATES SHOULD AID IN STRONG DOWNDRAFT POTENTIAL IN
   ADDITION TO LARGE HAIL. ADDITIONAL STORM DEVELOPMENT WILL LIKELY
   OCCUR WWD ALONG FRONTAL ZONE WITH ACTIVITY SPREADING SEWD ACROSS THE
   OH RIVER LATER THIS AFTERNOON INTO EVENING.
   
   ..MEAD.. 05/07/2005
   
   ...NOTICE...
   THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
   SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
   WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
   IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
   CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
   WILL PROVIDE DETAILS ON THE TRANSITION.
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z