SPC AC 310817
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0317 AM CDT TUE MAY 31 2005
   
   VALID 021200Z - 031200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CENTRAL
   AND NRN PLAINS...
   
   ...SYNOPSIS...
   MODELS ARE IN GENERAL AGREEMENT WITH AN UPPER TROUGH REMAINING OVER
   THE WRN STATES AND DEEPENING ON THURSDAY...WITH A BROAD RIDGE
   DOWNSTREAM ACROSS THE ERN HALF OF THE U.S.  LATEST MODELS ARE IN
   BETTER CONSENSUS WITH THE TRACK OF THE SRN STREAM TROUGH...NOW
   LOCATED AT 127W 25 N...WITH IT MOVING INTO SWRN TX BY THE END OF DAY
   3.
   
   ...PORTIONS OF THE CENTRAL HIGH PLAINS TO CENTRAL SD/NEB...
   A SHORT WAVE TROUGH EMBEDDED WITHIN THE LARGER WRN TROUGH IS
   EXPECTED TO EXTEND FROM ID TO THE FOUR CORNERS REGION AND WILL MOVE
   NEWD ACROSS THE CENTRAL HIGH PLAINS THURSDAY AFTERNOON.  SWLY MID
   LEVEL FLOW WILL STRENGTHEN ACROSS THE CENTRAL PLAINS TO 40-50 KT. 
   SLY LOW LEVEL FLOW ACROSS THE PLAINS WILL ALLOW RICHER BOUNDARY
   LAYER MOISTURE OVER TX TO ADVECT NWD.  THIS MOISTURE COMBINED WITH
   STEEP MID LEVEL LAPSE RATES IS EXPECTED TO RESULT IN AN AXIS OF
   MODERATE-STRONG INSTABILITY FROM SRN/WRN TX NWD ACROSS THE CENTRAL
   HIGH PLAINS AND THEN NNEWD INTO THE DAKOTAS.
   
   A COLD FRONT IS EXPECTED TO MOVE SEWD AND EXTEND FROM THE CENTRAL
   DAKOTAS TO SERN WY BY 00Z...WITH A DRY LINE EXTENDING SWD ALONG THE
   CO/KS BORDER INTO WRN TX.  THUNDERSTORMS SHOULD DEVELOP ALONG THE
   COLD FRONT SWWD TO WHERE THIS BOUNDARY INTERSECTS THE DRY LINE. 
   CAPE/SHEAR VALUES SUGGEST THE POTENTIAL FOR STORM ORGANIZATION WITH
   SUPERCELLS LIKELY.
   
   DEVELOPMENT FURTHER S INTO WRN KS TO THE TX PANHANDLE WILL BE
   CONDITIONAL ON THE STRENGTH OF THE CAP.
   
   THUNDERSTORMS WILL PERSIST THURSDAY EVENING/NIGHT ACROSS CENTRAL NEB
   INTO THE CENTRAL/ERN DAKOTAS WHERE SUFFICIENT ELEVATED CAPE/SHEAR
   WILL SUPPORT AT LEAST SOME THREAT FOR SEVERE STORMS.
   
   ...SWRN TX...
   MODELS DIFFER ON THE DEVELOPMENT OF THUNDERSTORMS ACROSS SWRN TX
   WITH RESPECT TO THE INCREASE OF LARGE SCALE ASCENT AHEAD OF THE SRN
   STREAM TROUGH. CAPE/SHEAR VALUES DURING THE AFTERNOON WOULD SUPPORT
   SEVERE STORMS...IF THE NAM VERIFIES WITH ACTIVITY SPREADING FROM THE
   HIGHER TERRAIN OF FAR WEST TX INTO SWRN TX THURSDAY
   AFTERNOON/EVENING.  OTHERWISE...THUNDERSTORMS SHOULD BE LIKELY
   ACROSS MUCH OF SWRN TX THURSDAY NIGHT WITH SOME THREAT FOR SEVERE
   STORMS.
   
   ...ERN SD/NRN MN TO NWRN WI/FAR WRN UP OF MI...
   THE NAM SUGGESTS THE POTENTIAL FOR SUFFICIENT INSTABILITY ACROSS
   THIS REGION BY EARLY THURSDAY AFTERNOON...WITH DEEP LAYER SHEAR
   STRONG ENOUGH FOR A FEW SEVERE STORMS. GIVEN MODEL UNCERTAINTY WITH
   THIS THREAT AREA...A LOW PROBABILITY FOR SEVERE HAS BEEN FORECAST.
   
   ...FL...
   MODELS SUGGEST SEVERAL EPISODES OF THUNDERSTORMS WILL MOVE ACROSS
   THE FL PENINSULA ON THURSDAY DAY 3.  DESPITE UNCERTAINTY IN THE
   AMOUNT OF SURFACE BASED CAPE EXPECTED TO DEVELOP...20-30 KT OF SWLY
   MID LEVEL FLOW COMBINED WITH AT LEAST MARGINAL INSTABILITY AND
   MODEST DEEP LAYER SHEAR SHOULD SUPPORT A FEW STRONG STORMS. 
   ISOLATED WIND GUSTS AND/OR HAIL APPROACHING SEVERE LEVELS SHOULD BE
   THE PRIMARY THREATS.
   
   ..PETERS.. 05/31/2005
   
   ...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 WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1100Z