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

   SPC AC 081627
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1127 AM CDT SUN MAY 08 2005
   
   VALID 081630Z - 091200Z
   
   THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM SPW 40
   NNE OMA 25 NE OLU 25 S MHE 35 NW HON 40 ENE MBG 55 WSW JMS 15 NNW
   TVF 20 NW BJI 30 S AXN SPW.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 N
   ELO 55 N EAU 30 N IRK 30 ENE SZL 10 E LIT 25 WSW MLU BPT 40 S LRD
   ...CONT... 50 NW DRT 25 SSW LTS 35 SW P28 30 SSE HSI 25 NE 9V9 30
   NNW PHP 15 N Y22 65 N DVL.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 NNW FCA 35 WSW GTF
   15 NE LVM 25 ESE COD 35 SSW CPR 10 SSE CYS 10 SE SNY 35 S REJ 35 ESE
   SDY 60 NNE ISN ...CONT... 75 ESE ANJ 50 NE MKG 10 WNW FWA 35 WNW JKL
   15 ENE CSV 25 ENE HSV 55 SE GWO 40 NE MCB 45 SE HUM ...CONT... 40
   SSW P07 35 NE FST 20 ENE HOB 30 WNW LBB 45 E AMA 25 WNW GAG 20 N LBL
   TAD 50 ENE DRO 40 NNE CNY 40 WNW PUC 35 WNW U24 20 SE ELY 40 ENE TPH
   15 NE BIH 15 ESE FAT 35 W FAT 20 WSW SJC.
   
   ...THERE IS A MDT RISK OF SVR TSTMS OVER ERN SD/SERN ND/FAR WRN
   MN...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER MUCH OF THE GREAT
   PLAINS...
   
   A LARGE AREA WILL BE AFFECTED BY SEVERE THUNDERSTORMS TODAY AS SLOW
   MOVING LONGWAVE TROUGH CONTINUES MOVING EWD ACROSS THE GREAT PLAINS.
    BROAD ELEVATED-MIXED LAYER HAS OVERSPREAD THE PLAINS AHEAD OF THIS
   SYSTEM WITH 7+ C/KM MID LEVEL LAPSE RATES.  IN ADDITION...A NARROW
   AXIS OF GULF MOISTURE RETURN IS NOW EVIDENT ACROSS THE ERN HALF OF
   THE GREAT PLAINS.
   
   ...NRN/CENTRAL PLAINS...
   THOUGH DEW POINTS WILL NOT BE HIGH FOR THIS TIME OF YEAR /MID 50S TO
   LOWER 60S F/...VERY STEEP LAPSE RATES AND ABUNDANT HEATING WILL
   SUPPORT AN AXIS OF MODERATE INSTABILITY FROM ERN NEB/WRN IA NWD INTO
   THE RED RIVER VALLEY.  EXPECT THUNDERSTORMS WILL DEVELOP NEAR LOW
   CENTER AND SW-NE ORIENTED SURFACE FRONT ACROSS NRN SD AND
   CENTRAL/ERN ND AROUND 18-19Z...WITH FURTHER DEVELOPMENT SWD ALONG
   DRY LINE/COLD FRONT INTO CENTRAL SD/ERN NEB BY 21Z.  DEEP LAYER
   SHEAR FROM 35-45 KT WILL SUPPORT SUPERCELLS AND SMALL LINES. PRIMARY
   THREATS WILL BE LARGE HAIL /SOME OF WHICH COULD EXCEED 2 INCHES IN
   DIAMETER/ AND DAMAGING WINDS.  HOWEVER...TORNADOES MAY BE AN
   ADDITIONAL HAZARD AS SURFACE LOW SHIFTS EWD INTO ERN SD THROUGH THE
   EARLY EVENING AND BACKS BOUNDARY LAYER FLOW OVER THE ERN
   DAKOTAS/SWRN MN/NERN NEB.  GIVEN PROXIMITY TO UPPER LOW AND AMOUNT
   OF LARGE SCALE ASCENT EXPECTED TO OVERSPREAD A DESTABILIZING WARM
   SECTOR...COVERAGE/CONFIDENCE IN SEVERE THREAT WARRANTS MDT RISK INTO
   THE MID EVENING OVER A PORTION OF THIS REGION.
   
   ...KS/WRN MO SWD INTO THE SRN PLAINS ALONG DRY LINE...
   SEVERE RISK WILL BE PREVALENT...BUT MORE CONDITIONAL SWD ALONG THE
   DRY LINE TODAY.  12Z ETA IS MOST AGGRESSIVE IN DEVELOPING
   THUNDERSTORMS INTO CENTRAL OK/KS BETWEEN 21-00Z...WHILE RUC FAILS TO
   PRODUCE MOIST CONVECTION. PRONOUNCED DRY LINE AND ABUNDANT HEATING
   WILL SUPPORT AN AXIS OF STRONG INSTABILITY AND WEAK CAP BY THE
   MID/LATE AFTERNOON FROM CENTRAL KS SWD INTO WRN/CENTRAL OK AND WRN
   TX.  NORTHWEST TX WILL BE LESS UNSTABLE WITH MORE CAPPING AS IT
   REMAINS INFLUENCED BY CONVECTIVELY STABLE AIR EXPECTED TO HOLD OVER
   CENTRAL TX...AND DEGREE OF INSTABILITY INTO CENTRAL OK MAY ALSO BE
   AFFECTED BY THIS AIR MASS.  REGARDLESS...AMOUNT OF INSTABILITY AND
   LARGE LAPSE RATES SUGGEST ANY STORM WHICH CAN INITIATE WILL BECOME
   SEVERE QUICKLY WITH PRIMARY THREAT OF LARGE HAIL.  WITH FORECAST
   SOUNDINGS ONLY INDICATING 25-35 KT DEEP LAYER SHEAR...SUPERCELL
   STRUCTURES MAY BE BRIEF WITH STORMS MORE LIKELY CONGEALING INTO
   CLUSTERS.
   
   IN ADDITION...ELEVATED THUNDERSTORMS WILL LIKELY CONTINUE SPREADING
   NNEWD AWAY FROM THE OZARK PLATEAU/SERN KS THROUGH THE DAY.  THOUGH
   IT APPEARS THESE STORMS WILL REMAIN SLIGHTLY ELEVATED INTO ERN KS
   AND WRN/CENTRAL MO...STEEP MID LEVEL LAPSE RATES MAY SUPPORT
   MARGINALLY SEVERE HAIL AND POSSIBLY ISOLATED WIND DAMAGE.
   
   ...CENTRAL TX...
   E-W ORIENTED OUTFLOW BOUNDARY WAS WELL DEFINED THIS MORNING ACROSS
   CENTRAL TX...WIT A SLOW SWD MOTION STILL OBSERVED.  WEAK MID LEVEL
   IMPULSE IS MOVING ACROSS SWRN TX ATTM...AND SHOULD ENHANCE
   THUNDERSTORMS ACROSS CENTRAL TX GIVEN FEED OF VERY STEEP LAPSE RATES
   AND RICH MARITIME MOISTURE EVIDENT ACROSS SOUTH TX. MCS WILL LIKELY
   EVOLVE OUT OF THIS CONVECTION AND SPREAD ESEWD TOWARDS THE UPPER TX
   COAST TODAY.  DEEP LAYER SHEAR NEAR 50 KT WILL BE MORE THAN
   SUFFICIENT FOR SUPERCELLS WITH VERY LARGE HAIL THREAT. IF BOUNDARY
   CAN STALL AND ALLOW STORMS TO BE FED BY VERY WARM/MOIST WARM
   SECTOR...TORNADO THREAT MAY INCREASE AS STORMS MOVE ALONG IT THIS
   AFTERNOON.  IF STORMS CONGEAL ALONG COMMON OUTFLOW BOUNDARY...THEN
   BOW ECHO SYSTEM COULD EVOLVE AND INCREASE THE THREAT OF DAMAGING
   WINDS INTO THE EARLY/MID EVENING.
   
   ...NRN INTERMOUNTAIN WEST...
   LARGE UPPER LOW REMAINS OFF THE NW COAST...THOUGH WEAK IMPULSES
   APPEAR TO BE EJECTING AND WILL LIFT NEWD ACROSS ORE AND NWD INTO WA
   TODAY. CLOUDS REMAIN EXTENSIVE OVER THE REGION AND WILL HINDER
   HEATING/DESTABILIZATION.  HOWEVER...STORMS WHICH FORM NEAR THESE
   SHORTWAVES WILL MAINTAIN A THREAT OF MARGINALLY SEVERE HAIL.
   
   ..EVANS/TAYLOR.. 05/08/2005
   
   ...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 2000Z