[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 210534
SWODY1
SPC AC 210532

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1232 AM CDT WED JUL 21 2004

VALID 211200Z - 221200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 NNW
ROC 20 SSE PIT 30 SSE LUK 20 NW UIN 50 WNW CNK 25 NNW EAR 30 WSW MSP
40 ENE ELO.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 75 SSW GBN 40 ESE IGM
35 ENE DRA BIH SAC 10 S RBL 10 SE LMT 55 ESE BNO 45 NW SUN 15 NE MQM
BIL 10 NE RAP 15 NNE BKX 40 NNE FAR 30 WSW P24 55 SE HVR 50 NW FCA
...CONT... 65 WNW MFE 50 ENE COT 40 E AUS 30 NNW POE 20 W BTR 30 N
BVE ...CONT... 60 SSE CTY AYS AHN CHA 15 N ARG 60 N JLN 35 NNW END
30 ENE LBB 35 ESE P07 ...CONT... 30 E AUG 35 NW GFL 35 SSW IPT 35
WSW MRB 20 NW LYH 45 N RWI 25 SE ORF.

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDDLE MO VALLEY EWD
ACROSS THE GREAT LAKES AND NRN OH VALLEY...

...SYNOPSIS...
BROAD...MID-LEVEL TROUGH IS FORECAST TO INTENSIFY OVER CNTRL CANADA
THROUGH THE DAY 1 PERIOD WITH A BELT MODERATELY STRONG WINDS
SPREADING EWD FROM THE NRN HIGH PLAINS INTO THE NRN GREAT LAKES.
LEAD SHORTWAVE TROUGH /ANALYZED ON WATER VAPOR IMAGERY OVER THE NRN
HIGH PLAINS/ WILL TRANSLATE EWD FROM THE UPPER MS VALLEY INTO THE
CNTRL GREAT LAKES BY EARLY THIS EVENING...WITH STRONGER UPSTREAM
IMPULSE /NOW OVER SRN PORTIONS OF BRITISH COLUMBIA AND ALBERTA/
BECOMING INCREASINGLY SHEARED OVER THE NRN HIGH PLAINS TONIGHT.

AT THE SURFACE...NRN EXTENSION OF PRIMARY COLD FRONT /INITIALLY
EXTENDING FROM THE UPPER MS VALLEY SWWD INTO THE CNTRL HIGH PLAINS/
WILL PUSH EWD TODAY AND WILL LIKELY STRETCH FROM THE WRN GREAT LAKES
SWWD ACROSS THE MID MO VALLEY INTO ERN CO BY EARLY EVENING.

...GREAT LAKES/NRN OH VALLEY...
CURRENT RADAR/SATELLITE AND SHORT-TERM NWP DATA SUGGEST A COMPLEX
SCENARIO ACROSS THE REGION TODAY AND TONIGHT. IT APPEARS THAT
PRIMARY SEVERE WEATHER THREATS WILL BE ASSOCIATED WITH MCS /THE
EARLY STAGE OF WHICH MAY BE EVOLVING OVER SRN MN/ AS IT MOVES EWD
TODAY...AS WELL AS ADDITIONAL DEVELOPMENT ALONG REMNANT MCS OUTFLOW
AND SYNOPTIC FRONT ITSELF.

FORCING FOR ASCENT AHEAD OF LEAD SHORTWAVE TROUGH TRANSLATING ACROSS
THE GREAT LAKES SHOULD HELP SUSTAIN STORM CLUSTERS/FORWARD
PROPAGATING MCS EWD ACROSS WI...LAKE MI AND INTO LOWER MI TODAY.
THOUGH DOWNSTREAM AIRMASS IS NOT EXPECTED TO BE PARTICULARLY
UNSTABLE...CONTINUOUS FEED OF MUCH MORE UNSTABLE AIR OVER THE UPPER
MIDWEST/MIDDLE MS VALLEY ALONG WSWLY 20-30KT LLJ SHOULD PROMOTE
DEVELOPMENT OF INTENSE CONVECTIVE ACTIVITY ALONG SRN FLANK OF
SYSTEM. WHEN COUPLED WITH MODEST UNIDIRECTIONAL SHEAR
PROFILES...POTENTIAL WILL EXIST FOR CORRIDORS OF DAMAGING WINDS
ALONG SYSTEM TRACK.

OTHER SEVERE STORMS MAY WELL BE FOCUSED ALONG SYNOPTIC FRONT /OVER
THE WRN GREAT LAKES LATE THIS AFTERNOON/ AS WELL AS ANY RESIDUAL
OUTFLOW BOUNDARY FROM ANTICIPATED MCS /OVER THE SRN GREAT LAKES OR
NWRN OH VALLEY/. CLOSER PROXIMITY TO THE GREATER INSTABILITY WITH
MLCAPES APPROACHING 2000-3000 J/KG AND STRONGER DEEP-LAYER SHEAR
/ESPECIALLY OVER THE WRN GREAT LAKES/ SHOULD SUPPORT SUPERCELLS
AND/OR BOWING STRUCTURES CAPABLE OF DAMAGING WINDS/LARGE HAIL AND
POSSIBLY A COUPLE OF TORNADOES.

...IA/NEB SWWD INTO THE CNTRL/SRN HIGH PLAINS...
ADDITIONAL SEVERE STORMS WILL ALSO BE POSSIBLE LATER TODAY ALONG
IA/NEB PORTION OF SYNOPTIC COLD FRONT AND POSSIBLY OUTFLOW BOUNDARY
LEFT OVER FROM STORM CLUSTERS MOVING EWD ACROSS CNTRL NEB. THOUGH
DEEP-LAYER SHEAR WILL BE MARGINALLY STRONG /I.E. 20-30KTS THROUGH
THE LOWEST 6KM/...MODERATE TO STRONG INSTABILITY WITH MLCAPES OF
2000-3000 J/KG SHOULD PROMOTE VIGOROUS UPDRAFT DEVELOPMENT. MOST
INTENSE STORMS/STORM CLUSTERS WILL POSE A DAMAGING WIND/HAIL THREAT.


VERTICAL WIND SHEAR WILL PROGRESSIVELY WEAKEN WITH SWWD EXTENT ALONG
COLD FRONT AND LEE TROUGH OVER THE CNTRL/SRN HIGH PLAINS.
HOWEVER...MODERATE INSTABILITY AND EXPECTED DEEPLY-MIXED CHARACTER
OF BOUNDARY-LAYER SHOULD PROMOTE A FEW HIGH-BASED....STRONG STORMS
INVOF THESE BOUNDARIES WHICH WILL BE CAPABLE OF ISOLATED WIND/HAIL.

..MEAD/TAYLOR.. 07/21/2004

...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.