Categorical Graphic
Probabilistic Tornado Graphic
Probabilistic Damaging Wind Graphic
Probabilistic Large Hail Graphic

   SPC AC 120557
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1257 AM CDT SUN JUN 12 2005
   
   VALID 121200Z - 131200Z
   
   THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 SW
   LBL 30 W GAG 20 NE SPS 45 W MWL 30 WSW ABI 75 ESE LBB 30 ESE PVW 40
   NNE AMA 40 SW LBL.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 SE
   P07 25 SE BGS 45 SE CVS 15 SW DHT 15 SE LAA 20 E LIC 20 WNW BBW 40 E
   SUX 30 N CID MLI 40 SSW TBN 20 W PRX 45 NE JCT 65 W COT.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 WSW HUM 35 ESE ESF
   50 NNW POE 40 NE CLL 55 E SAT 45 SSE LRD ...CONT... 85 SSE MRF 35
   NNE CNM 35 ENE ONM 20 WNW GNT 10 SSW DPG 30 NNE TWF 50 WSW MSO 45 NE
   4OM ...CONT... 65 NNE MOT 30 NNW ABR 30 NW RWF 35 E MSP 20 SSE ANJ
   ...CONT... 25 ENE NEL HGR 30 ESE MGW 35 ENE CRW 20 S 5I3 20 SSW HSS
   25 NE AGS 35 SW CHS.
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS THE ERN HALF OF THE TX
   PANHANDLE INTO WRN N TX...AND EWD INTO SWRN OK....
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS /
   MIDDLE MO VALLEY REGION SWD ACROSS OK INTO PARTS OF WRN AND CENTRAL
   TX...
   
   ...SYNOPSIS...
   LARGE UPPER TROUGH OVER THE ROCKIES IS FORECAST TO MOVE EWD INTO THE
   PLAINS STATES THIS PERIOD WHILE TAKING ON AN INCREASINGLY-NEGATIVE
   TILT.  MEANWHILE...LARGE RIDGE WILL PREVAIL ACROSS THE ATLANTIC
   COAST STATES AND EWD INTO THE WRN ATLANTIC.
   
   AT THE SURFACE...PATTERN IS FORECAST TO REMAIN FAIRLY NONDESCRIPT. 
   SURFACE LOW ASSOCIATED WITH WRN TROUGH IS FORECAST TO SHIFT NEWD
   FROM ERN NM / SERN CO TO NRN NEB THROUGH THE PERIOD. 
   MEANWHILE...REMNANTS OF ARLENE SHOULD MOVE GENERALLY NWD ACROSS TN /
   KY AND INTO IN BY 13/12Z.
   
   ...CENTRAL AND SRN PLAINS ACROSS THE MIDDLE MO VALLEY...
   LARGE-SCALE PATTERN LOOKS FAVORABLE FOR SIGNIFICANT SEVERE WEATHER
   EPISODE -- PARTICULARLY OVER PARTS OF TX AND OK.  A MAIN
   COMPLICATING FACTOR WITH RESPECT TO THIS FORECAST WILL BE THE
   ONGOING STORMS NOW OVER PARTS OF NERN NM AND THE TX PANHANDLE INTO
   WRN OK / SWRN KS.
   
   ATTM...IT APPEARS THAT THESE STORMS SHOULD CONTINUE EVOLVING INTO AN
   MCS...AND SHOULD MOVE SLOWLY ENEWD ACROSS WRN OK / SRN KS THROUGH
   THE BEGINNING OF THE DAY 1 PERIOD.  AN ASSOCIATED OUTFLOW BOUNDARY
   IS FORECAST TO EVOLVE ACROSS SWRN OK / INVOF THE RED RIVER
   VALLEY...AND WWD / NWWD INTO THE TX PANHANDLE. 
   
   ONGOING STORMS MAY PERSIST THROUGH THE DAY...WHILE AIRMASS BECOMES
   MODERATELY UNSTABLE AWAY FROM CONVECTION / S OF OUTFLOW BOUNDARY. 
   APPROACH OF UPPER TROUGH SHOULD THEN SUPPORT NEW STORM DEVELOPMENT
   DURING THE AFTERNOON ALONG THE OUTFLOW BOUNDARY...AS WELL AS SWD
   ALONG THE DRYLINE.  SCENARIO ACROSS WRN / CENTRAL KS IS MORE
   COMPLICATED...AS ONGOING CONVECTION WILL LIKELY AFFECT LOCATION /
   INTENSITY OF NEW STORM DEVELOPMENT.
   
   MID-LEVEL FLOW IS FORECAST TO STRENGTHEN / BACK WITH TIME ACROSS OK
   / WRN PORTIONS OF TX AS TROUGH APPROACHES.  WITH PERSISTENT SLY
   LOW-LEVEL JET EXPECTED...DEEP-LAYER SHEAR WILL BECOME INCREASINGLY
   FAVORABLE FOR STRONG SUPERCELLS.  THOUGH LARGE HAIL WILL LIKELY BE
   THE PRIMARY SEVERE THREAT...LOCALLY DAMAGING WINDS AND A FEW
   TORNADOES CAN ALSO BE EXPECTED.  ASSUMING PERSISTENT W-E OUTFLOW
   BOUNDARY DOES INDEED EVOLVE ACROSS THE TX PANHANDLE / SRN OK...THIS
   BOUNDARY COULD BE A FOCUS FOR TORNADIC SUPERCELL DEVELOPMENT.
   
   OVERNIGHT...SURFACE LOW SHOULD MOVE NWD TOWARD NEB WHILE TRAILING
   TROUGH STRENGTHENS / SHIFTS EWD ACROSS THE CENTRAL AND SRN PLAINS
   AHEAD OF UPPER TROUGH. CONVERGENCE ALONG THIS BOUNDARY MAY FAVOR
   MORE LINEAR ORGANIZATION OF STORMS WITH TIME...AS CONVECTION SHIFTS
   EWD ACROSS TX / OK / KS AND TOWARD THE MID MO VALLEY.  THOUGH PARTS
   OF THE REGION WILL LIKELY HAVE BEEN STABILIZED TO SOME DEGREE BY
   EARLIER CONVECTION...THREAT FOR DAMAGING WINDS AND HAIL ALONG WITH
   ISOLATED TORNADOES WILL LIKELY PERSIST ACROSS PARTS OF THE REGION
   THROUGH THE END OF THE PERIOD.
   
   ...NERN CONUS INTO THE GREAT LAKES / OH VALLEY...
   MOIST AIRMASS WILL AGAIN BECOME MODERATELY UNSTABLE DURING THE
   AFTERNOON ACROSS THIS REGION.  WEAK SURFACE BOUNDARY IS FORECAST TO
   MOVE EWD ACROSS WI DURING THE DAY...AND MAY PROVIDE A FOCUS FOR
   STORM DEVELOPMENT.  ELSEWHERE...LESS OBVIOUS LOW-LEVEL FORCING
   MECHANISMS WILL LIKELY ALLOW FOR THE DEVELOPMENT OF SCATTERED TO
   ISOLATED STORMS.  
   
   DESPITE MARGINAL DEEP-LAYER SHEAR...DEGREE OF INSTABILITY SUGGESTS A
   POTENTIAL FOR A FEW STRONGER / MULTICELL STORM CLUSTERS. 
   THEREFORE...WILL MAINTAIN 5% SEVERE HAIL / WIND PROBABILITY ACROSS
   THIS REGION.
   
   ...TN VALLEY REGION...
   REMNANTS OF ARLENE ARE FORECAST TO MOVE NWD ACROSS PARTS OF TN AND
   KY THIS PERIOD....WHILE ASSOCIATED WIND FIELD WILL CONTINUE TO
   SLOWLY DECREASE WITH TIME.  HOWEVER...VERY MOIST LOW-LEVEL AIRMASS
   AND SUFFICIENT LOW-LEVEL SHEAR -- AT LEAST THROUGH THE DAYTIME HOURS
   -- MAY SUPPORT AN ISOLATED / BRIEF TORNADO E / NE OF CIRCULATION
   CENTER.
   
   ..GOSS/GUYER.. 06/12/2005
   
   ...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 1300Z