SPC AC 211623
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1123 AM CDT THU JUL 21 2005
   
   VALID 211630Z - 221200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 NNW
   CLE 15 NNW CMH 35 S SDF HOP 25 SE CGI 60 SSW STL 25 S IRK 45 NNE FNB
   15 SSW BBW 30 SE AIA 45 NE DGW 40 N 81V 35 S SDY 45 E ISN 30 E MOT
   50 S FAR 35 E EAU 15 ENE MBL 60 NNE MTC.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 50 SE
   YUM 65 WNW GBN 45 WSW PRC 25 SW FLG 25 S INW 40 SSE SOW 15 E DUG.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM CZZ 15 ESE RAL 15 WSW
   PMD VBG ...CONT... 20 SSW HQM 50 WSW 4OM 50 E 63S 10 WNW FCA 45 N
   3DU 20 WSW DLN 20 ENE PIH 25 E EVW 30 SSE RKS 10 SSW RWL 55 NNE CPR
   10 NNE MLS 65 N OLF ...CONT... 25 ENE ELO 50 NW IWD 15 NE IWD 10 SW
   MQT 35 NNW PLN 65 ENE APN ...CONT... 35 S HUL 20 W BGR 20 S RUT 25
   WNW MSV 15 NE ABE 25 NE NEL.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 SW TCC 30 NW HOB
   25 WNW MAF 40 SSE BGS 25 WNW BWD 10 E SEP 10 SSE DAL 20 WNW PRX 25
   NNW PGO 15 NNE FYV 20 NW UMN 30 NNW JLN 30 SSE EMP 25 SSE SLN 30 WSW
   RSL 50 NNW GCK 15 SSW LAA 15 NNW CAO 35 SW TCC.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN
   PLAINS...CNTRL PLAINS...UPPER MIDWEST AND OH VALLEY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF AZ...
   
   ...NRN AND CNTRL PLAINS...
   SEVERAL SHORTWAVE TROUGHS ARE CURRENTLY MOVING ESEWD ACROSS THE NRN
   PLAINS THIS MORNING. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TWO
   DISTURBANCES...ONE LOCATED IN FAR NE MT AND ONE LOCATED IN NE WY.
   ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT SCATTERED
   THUNDERSTORM DEVELOPMENT THIS AFTERNOON IN THE DAKOTAS AND NRN NEB
   LATE THIS AFTERNOON AND/OR THIS EVENING.
   
   SFC ANALYSIS CURRENTLY SHOWS A NEARLY STATIONARY FRONT IN SE MT
   EXTENDING SEWD INTO WRN NEB. A WARM FRONT EXTENDS NEWD FROM A SFC
   LOW ACROSS CNTRL NEB INTO NRN IA. AN AXIS OF MODERATE INSTABILITY
   EXISTS ALONG AND JUST NORTH OF THE FRONT WHERE SFC DEWPOINTS ARE IN
   THE UPPER 60S F. ALTHOUGH A CAPPING INVERSION EXISTS ACROSS THE
   REGION...IT APPEARS THE HIGHER TERRAIN IN THE BLACK HILLS WILL BE
   ENOUGH TO RESULT IN INITIATION LATE THIS AFTERNOON. STORMS SHOULD
   SPREAD ESEWD ACROSS SRN SD AND NRN NEB ALONG THE INSTABILITY AXIS
   LATER THIS AFTERNOON INTO EARLY THIS EVENING.
   
   FORECAST SOUNDINGS IN SRN SD LATE THIS AFTERNOON SHOW STRONGLY
   VEERING WIND PROFILES IN THE LOW TO MID-LEVELS. THIS COMBINED WITH
   LARGE TEMP-DEWPOINT SPREADS WILL CREATE CONDITIONS FAVORABLE FOR
   HIGH-BASED SUPERCELLS LATE THIS AFTERNOON. STEEP MID-LEVEL LAPSE
   RATES COMBINED WITH MODERATE DEEP LAYER SHEAR WILL BE SUFFICIENT FOR
   LARGE HAIL AND ISOLATED WIND DAMAGE. VERY LARGE HAIL WILL ALSO BE
   POSSIBLE WITH SUPERCELLS IN AREAS WITH ENHANCED INSTABILITY. IT
   APPEARS THAT AN MCS WILL DEVELOP AND MOVE ESEWD INTO NRN NEB THIS
   EVENING. DUE TO THE RELATIVELY HIGH INSTABILITY IN PLACE...A SEVERE
   THREAT MAY CONTINUE WITH THE MCS OVERNIGHT INTO ERN NEB AND IA.
   
   ...UPPER MIDWEST/OH VALLEY...
   WATER VAPOR AND RUC ANALYSIS CURRENTLY SHOWS A STRONG SHORTWAVE
   TROUGH IN IA AND SRN MN. THIS FEATURE WILL DRIFT ESEWD TODAY
   PROVIDING SUPPORT FOR SCATTERED TO NUMEROUS THUNDERSTORMS ACROSS THE
   REGION THIS AFTERNOON AND TONIGHT.
   
   A CONVECTIVE LINE IS CURRENTLY ONGOING IN SERN WI AHEAD OF THE
   SHORTWAVE TROUGH. AS THE LINE MOVES ACROSS LAKE MI INTO LOWER
   MI...THE SEVERE THREAT MAY CONTINUE INTO THE AFTERNOON HOURS AS SFC
   TEMPS HEAT UP AHEAD OF THE LINE. THE LINE HAS CAUSED STABILIZATION
   IN SRN WI AND THIS MAY BE A LIMITING FACTOR FOR SEVERE THERE LATER
   TODAY. SOUTH OF THE CONVECTION...ACROSS ERN AND SRN IL...IND AND NRN
   KY...STRONG INSTABILITY IS ALREADY IN PLACE. BY
   MID-AFTERNOON...MLCAPE VALUES SHOULD EXCEED 4000 J/KG OVER MUCH OF
   THE OH VALLEY AND THIS COMBINED WITH DEEP LAYER SHEAR OF 25 TO 30 KT
   AND RELATIVELY STEEP MID-LEVEL LAPSE RATES WILL BE SUFFICIENT FOR
   SEVERE STORMS. THE STRONG INSTABILITY AND STEEPENING LOW-LEVEL LAPSE
   RATES SHOULD BE FAVORABLE FOR BOWING LINE SEGMENTS WITH WIND DAMAGE
   THE PRIMARY THREAT.
   
   ...AZ...
   CONVECTION WILL LIKELY DEVELOP IN THE WHITE MTNS AND ALONG THE
   MOGOLLON RIM THIS AFTERNOON. THE STORMS WILL GRADUALLY PROPAGATE 
   WSWWD INTO THE LOWER ELEVATIONS WHERE SFC DEWPOINTS ARE IN THE LOWER
   60S F AND MODERATE INSTABILITY WILL BE IN PLACE. THIS COMBINED WITH
   25 TO 30 KT OF VERTICAL SHEAR SHOULD BE SUFFICIENT FOR HIGH-BASED
   MULTICELL STORMS. LARGE TEMP-DEWPOINT SPREADS WILL RESULT IN A
   ISOLATED WIND DAMAGE THREAT WITH HAIL ALSO POSSIBLE DUE TO THE STEEP
   MID-LEVEL LAPSE RATES IN PLACE.
   
   ...ORE...
   WATER VAPOR IMAGERY AND RUC ANALYSIS CURRENTLY SHOWS AN UPPER-LOW
   CURRENTLY OFF THE WEST COAST. A LARGE BAND OF ASCENT ASSOCIATED WITH
   THE UPPER-TROUGH WILL SPREAD EWD INTO ORE TODAY SUPPORTING
   THUNDERSTORM DEVELOPMENT THIS AFTERNOON. SFC DEWPOINTS IN THE 50S F
   SHOULD RESULT IN ENOUGH INSTABILITY FOR STRONG UPDRAFTS AS STORMS
   INITIATE IN THE HIGHER TERRAIN. OBJECTIVE ANALYSIS CURRENTLY SHOWS
   MODERATE DEEP LAYER SHEAR IN PLACE ACROSS WRN AND CNTRL ORE WITH
   STEEP MID-LEVEL LAPSE RATES. THIS COMBINED WITH LIFT AND INSTABILITY
   MAY BE SUFFICIENT FOR A MARGINAL WIND DAMAGE OR HAIL THREAT LATE
   THIS AFTERNOON AND EARLY THIS EVENING.
   
   ..BROYLES/CROSBIE.. 07/21/2005
   
   ...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