SPC AC 171615
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1115 AM CDT SUN APR 17 2005
   
   VALID 171630Z - 181200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 SSE
   FST 45 N MRF 10 N GDP 40 E ALM 15 NE 4CR 55 SSE RTN 55 SSW LAA 30 SW
   MCK 35 NNE HLC 25 WSW RSL 35 ESE DDC 35 ENE GAG 45 SSW CDS 35 SSE
   BGS 30 SSE FST.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 NNE HVR 35 E LVM
   30 WNW IDA 25 WSW SUN 60 W BOI 55 SE RDM 30 NW RDM PDX 10 NNE OLM
   BLI.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 10 SE RRT 30 ENE AXN
   STJ 50 ENE OKC 10 E BWD 70 W COT.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 SSW DMN 70 NNW SVC
   40 W FMN 25 NW MTJ 20 N EGE CYS 55 NW CDR 25 SW REJ 45 ESE GDV 60 N
   ISN.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL AND SOUTHERN HIGH
   PLAINS...
   
   ...CENTRAL AND SOUTHERN HIGH PLAINS...
   
   WHILE COLD TROUGHING CONTINUES TO DEVELOP INTO PAC NW...A WEAK SRN
   BRANCH IMPULSE WILL BE MOVING SLOWLY NEWD FROM CO/NRN NM INTO
   CENTRAL HIGH PLAINS BY THIS EVENING.  THIS MID/UPPER LEVEL FEATURE
   SHOWS UP WELL ON BOTH WV IMAGERY AND THE ACARS WINDS WITH A VORT MAX
   VICINITY ALS ATTM.
   
   A 30 PLUS KT LLJ THAT EXTENDS FROM LOWER RIO GRANDE VALLEY NWD THRU
   SRN HIGH PLAINS INTO WRN KS IS CONTINUING TO TRANSPORT A STEADILY
   INCREASING AMOUNT OF LOW LEVEL MOISTURE NWD.  ATOP THIS MOISTURE
   THERE PERSISTS AN ELEVATED MIX LAYER WITH LAPSE RATES FROM 7-8 C/KM.
   CURRENT MID/HIGH CLOUDS AHEAD OF CENTRAL ROCKIES S/WV TROUGH SHOULD
   THIN AND/OR DISSIPATE SUFFICIENTLY TO ALLOW STRONG HEATING TO OCCUR
   CENTRAL HIGH PLAINS THIS AFTERNOON.
   
   BY MID AFTERNOON MLCAPES SHOULD RANGE FROM 1000-1500 J/KG WRN KS
   INTO OK/TX PANHANDLE AREAS WITH LITTLE CIN REMAINING AFTER 21Z.
   
   THUNDERSTORMS EXPECTED TO INITIATE BY MID/LATE AFTERNOON OVER HIGH
   PLAINS VICINITY OF CO/KS BORDER SUPPORTED BY LARGE SCALE ASCENT
   ASSOCIATED WITH APPROACH OF UPPER TROUGH.  WHILE DEEP LAYER SHEAR
   GENERALLY LESS THAN 30KT REMAINS MARGINAL FOR TORNADIC
   SUPERCELLS...THE STEEP LAPSE RATES COUPLED WITH SFC-1KM SHEAR UP TO
   20KT WILL SUPPORT RELATIVELY HIGH BASED ROTATING STORMS.  LARGE HAIL
   WILL BE THE MOST LIKELY THREAT AS WELL AS LOCALIZED DOWNBURSTS GIVEN
   EXPECTED 30F T/TD SPREADS.
   
   SEVERE THREAT SHOULD PERSIST THRU THE EVENING AS STORMS PROPAGATE
   EWD AND BECOME OUTFLOW DOMINATED. THIS WILL MAINTAIN MARGINAL
   DAMAGING WIND THREAT PRIOR TO WEAKENING AS BOUNDARY LAYER DECOUPLES
   OVERNIGHT.
   
   FURTHER S INTO ERN NM/WRN TX STORMS SHOULD AGAIN DEVELOP OFF HIGHER
   TERRAIN OF ERN NM AND DRIFT EWD INTO WRN TX THIS EVENING.  A FEW
   COULD BE SEVERE BUT CAPPING COULD BE MORE OF A DETERRENT TO
   DEVELOPMENT DUE TO GREATER AMOUNT OF CURRENT CLOUD COVER TO SLOW
   HEATING AND A LITTLE WARMER MID LEVEL TEMPS.  NEVERTHELESS AT LEAST
   ISOLATED SEVERE IS LIKELY BY THIS EVENING AS STORMS PROPAGATE EWD
   OFF HIGHER TERRAIN INTO MOISTURE/INSTABILITY AXIS THAT WILL BE
   LINKED TO PERSISTENT SLY LLJ THRU WRN TX.
   
   ...NRN PLAINS...
   STRONG HEATING WRN DAKOTAS WITH AFTERNOON TEMPS INTO 80S APPROACHING
   90F WRN SD...EXPECTED TO WEAKEN CAP SUFFICIENTLY TO ALLOW AT LEAST
   ISOLATED SEVERE STORMS TO DEVELOP.  MOST LIKELY THREAT AREA WILL BE
   WCENTRAL SD ON WRN EDGE OF LOW LEVEL MOISTURE WHERE MUCAPES COULD BE
   AS HIGH AS 2000 J/KG SD WHERE SURFACE TEMPERATURES EXPECTED TO BE
   THE WARMEST. DEEP LAYER SHEAR LESS THAN 30KT EXPECTED TO LIMIT STORM
   INTENSITY AND COVERAGE...HOWEVER THE POTENTIAL AVAILABLE INSTABILITY
   MAY REQUIRE A PORTION OF THIS AREA TO BE UPGRADED IN AFTERNOON
   OUTLOOK.
   
   ..HALES/CROSBIE.. 04/17/2005
   
   ...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