SPC AC 221635
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1135 AM CDT SAT MAY 22 2004
   
   VALID 221630Z - 231200Z
   
   THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 10 WNW
   MCK IML 30 ESE AIA VTN YKN SPW MCW DBQ MLI LWD 20 SE BIE 40 SSE HSI
   10 WNW MCK.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM ART 35
   SSE SLK RUT EEN BDL 35 NNE EWR TTN HGR ZZV DAY MTO 10 SW BLV 10 W
   VIH CNU PNC FSI CDS GAG RSL HLC GLD LIC 30 ENE DEN DGW SHR BIL 70
   WNW MLS 45 S GDV REJ MHE MKT CWA TVC OSC.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SE DAB 35 N PIE
   ...CONT... 20 S MOB 45 ESE LUL 20 WSW MSL 50 NNE MSL 25 WNW BNA 35 N
   HOP 45 SW BLV 40 NNW SGF BVO 35 NNW ADM MWL 30 S BWD 15 NW DRT
   ...CONT... 70 S MRF 25 E MRF 15 W MAF 10 ESE PVW 55 S LBL 15 SE GCK
   50 NW GCK 25 NE COS 15 NW DRO 10 S U17 35 N P38 4LW 40 SE EUG 20 NNW
   ONP.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 W MSS 30 SSE AUG
   ...CONT... 30 NNE CTB 35 SSE HVR 45 SSW GGW 30 ESE SDY 20 N BIS 50
   NW ABR 25 ENE ABR 45 NE ATY 70 SSW DLH 30 WNW IMT 40 E PLN.
   
   ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER
   MUCH OF NEB AND IA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE
   CENTRAL/SOUTHERN PLAINS...MIDWEST STATES...GREAT LAKES...INTO
   WESTERN NEW ENGLAND...
   
   ...SIGNIFICANT SEVERE WEATHER EPISODE IS EXPECTED THIS
   AFTERNOON/EVENING FOR PARTS OF NEB/IA...
   
   MORNING WATER VAPOR LOOP SHOWS WELL-DEFINED SHORTWAVE TROUGH OVER
   THE CENTRAL ROCKIES.  THIS FEATURE WILL TRACK EAST-NORTHEASTWARD
   INTO THE CENTRAL PLAINS THIS AFTERNOON.  MEANWHILE...SURFACE LOW
   WILL DEEPEN OVER NORTHERN KS.  INCREASING SOUTHERLY LOW LEVEL WINDS
   FROM TX INTO MO/IA WILL MAINTAIN A VERY MOIST/UNSTABLE AIRMASS AHEAD
   OF DRYLINE AND IN WARM SECTOR OF LOW...SETTING THE STAGE FOR AN
   ACTIVE SEVERE WEATHER EVENT.  FARTHER EAST...BAND OF STRONG WESTERLY
   WINDS ALOFT PARALLEL TO SURFACE WARM FRONT FROM NORTHERN IL INTO
   NY/PA WILL ALSO PROVIDE A FAVORABLE ENVIRONMENT FOR ORGANIZED/SEVERE
   STORMS THIS AFTERNOON AND EVENING.
   
   ...CENTRAL PLAINS...
   LATEST SURFACE ANALYSIS SHOWS THE MAIN FRONT EXTENDING FROM NORTHERN
   NEB INTO SOUTHERN MN.  AN OUTFLOW BOUNDARY EXTENDS FROM NORTHERN KS
   INTO NORTHERN MO.  BETWEEN THE TWO BOUNDARIES...SURFACE WINDS ARE
   STRONGLY BACKED AND VISIBLE SATELLITE IMAGERY SHOWS SUBSTANTIAL
   HEATING WILL OCCUR.  SURFACE DEWPOINTS SHOULD RISE STEADILY THROUGH
   THE DAY IN THIS ZONE AS MOISTURE MIXES DOWNWARD...PROVIDING AN
   EXTREMELY UNSTABLE AIRMASS BY AFTERNOON /MLCAPE VALUES OVER 4000
   J/KG OVER CENTRAL/EASTERN NEB INTO WESTERN IA/.
   
   PRESENT INDICATIONS ARE THAT SCATTERED THUNDERSTORMS WILL FIRST
   INITIATE OVER THE HIGH PLAINS OF WESTERN NEB BY MID AFTERNOON AS
   SHORTWAVE TROUGH APPROACHES REGION.  STORMS WILL DEVELOP EASTWARD
   ACROSS CENTRAL NEB THROUGH THE AFTERNOON...WITH MORE THAN SUFFICIENT
   SHEAR FOR SUPERCELLS WITH VERY LARGE HAIL.  OTHER ISOLATED SUPERCELL
   STORMS WILL LIKELY DEVELOP RAPIDLY OVER EASTERN NEB AND
   WESTERN/CENTRAL IA BY LATE AFTERNOON OR EARLY EVENING...IN REGION OF
   WEAK LOW LEVEL WARM ADVECTION NORTH OF WEAKENING OUTFLOW BOUNDARY. 
   THESE STORMS APPEAR TO HAVE THE GREATEST RISK OF TORNADOES DUE TO
   VERY FAVORABLE LOW LEVEL SHEAR PROFILES AND MOIST BOUNDARY LAYER
   /1KM SHEAR OVER 20 KNOTS AND DEWPOINTS NEAR 70F/.  ALONG WITH STRONG
   TORNADOES...VERY LARGE HAIL ALSO APPEARS LIKELY.  CONSIDERED
   UPGRADING SMALL AREA FROM GRI/HSI - DSM TO HIGH RISK...BUT CONCERN
   OF CAP AND TIMING OF CONVECTIVE INITIATION LED TO MAINTENANCE OF
   MODERATE RISK. WILL RE-EVALUATE AT 20Z FOR CONFIDENCE IN INITIATION
   IN THIS REGION AND POSSIBLE UPGRADE.
   
   ...IL/IN/MI/OH...
   MCS CURRENTLY OVER WESTERN IL IS LIKELY TO RE-INTENSIFY THIS
   AFTERNOON /REF MCD 818/.  RATHER STRONG WINDS ALOFT AND VERY
   MOIST/UNSTABLE AIRMASS WILL SUPPORT A RISK OF LARGE HAIL AND
   DAMAGING WINDS IN STRONGER STORMS.  LOW END TORNADO POTENTIAL ALSO
   EXISTS ALONG WARM FRONT OVER LOWER MI...WHERE STRONGEST LOW LEVEL
   SHEAR PROFILES ARE PRESENT.  THIS ACTIVITY MAY TRACK AS FAR EAST AS
   OH/PA THIS EVENING BEFORE WEAKENING.
   
   ...NY/PA/NEW ENGLAND...
   SURFACE WARM FRONT CURRENTLY EXTENDS ALONG THE NY/PA BORDER INTO
   SOUTHERN NEW ENGLAND.  SOUTHWESTERLY LOW LEVEL WINDS ARE
   TRANSPORTING RICH MOISTURE INTO THIS AREA WITH DEWPOINTS NOW IN THE
   LOW/MID 60S.  POCKETS OF STRONG HEATING AND RELATIVELY STEEP LAPSE
   RATES WILL CONTRIBUTE TO MLCAPE VALUES OVER 2000 J/KG. MODELS
   SUGGEST A WEAK SHORTWAVE TROUGH WILL LOWER HEIGHTS IN THIS REGION
   THIS AFTERNOON...POSSIBLY AIDING IN THE DEVELOPMENT OF SCATTERED
   THUNDERSTORMS INVOF FRONT.  STRONG WESTERLY FLOW ALOFT APPEARS
   SUFFICIENT FOR ORGANIZED MULTICELL OR SUPERCELL STORMS CAPABLE OF
   DAMAGING WINDS AND LARGE HAIL. EASTWARD EXTENT OF SEVERE RISK INTO
   NEW ENGLAND IS UNCERTAIN DUE TO WINDS OFF THE ATLANTIC.
   
   ..HART/JEWELL.. 05/22/2004
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 2000Z