[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 181635
SWODY1
SPC AC 181633

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1133 AM CDT WED AUG 18 2004

VALID 181630Z - 191200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 WNW
CLE 60 W UNI 35 N LEX BMG 45 NNW COU STJ OMA 40 ESE MSP 15 NW IWD.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 N CTB 45 W LWT 30
SE SHR 35 NNW CDR VTN 10 SW MHE 20 WNW BRD 40 NNW ELO ...CONT... 20
E PNS 25 ENE CSG 45 ESE ATL 30 NW AHN 60 S TYS 25 ESE CHA 35 NW BHM
20 WSW TUP 20 E JBR 20 SW CGI 35 W MDH 45 SW STL 35 WNW TBN 20 WSW
JLN 15 S TUL 10 ENE DUA 25 NNW LFK 50 N BPT 40 WSW 7R4 ...CONT... 20
SSE YUM 35 WSW BLH 35 N TRM 15 NNE DAG 15 NNE NID 45 S BIH 55 NE MER
15 SSW RNO 80 SE 4LW 45 SSE BNO 55 NNE BNO 45 ESE YKM 30 NNE SEA 20
NE BLI.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MIDWEST AND
GREAT LAKES AREA....

...UPPER MIDWEST AND GREAT LAKES AREA...
AN INTENSE MID LEVEL TROUGH IS DIGGING ESEWD FROM SRN MANITOBA
TOWARD WI/MI PER WATER VAPOR IMAGERY AND 100 M HEIGHT FALLS AT INL
IN 12Z UPPER AIR ANALYSES.  AN ASSOCIATED STRONG SURFACE COLD FRONT
IS SURGING SWD ACROSS SD AND SEWD ACROSS MN AS OF MID MORNING...AND
THIS FRONT WILL CONTINUE SEWD ACROSS THE GREAT LAKES AND SWD INTO KS
BY TONIGHT.  A BAND OF ASCENT ALONG THE COLD FRONT WILL PROVIDE A
FOCUS FOR THUNDERSTORM INITIATION THROUGH THE PERIOD.

A W-E ORIENTED BAND OF CLOUDS/SCATTERED THUNDERSTORMS FROM IA ACROSS
NRN IL TO SRN LOWER MI DENOTES A WEAK LOW-MID LEVEL BAROCLINIC
ZONE...WITH THE RICHER LOW-LEVEL MOISTURE /SURFACE DEWPOINTS
MID-UPPER 60S/ GENERALLY CONFINED TO AREAS ALONG AND S OF THIS BAND.
 THE DEGREE OF INSTABILITY IS IN QUESTION N OF THIS BAND...WITH ONLY
A NARROW CORRIDOR OF MUCAPE VALUES FROM 500-1250 J/KG EXPECTED ALONG
THE FRONT ACROSS WI/UPPER MI THIS AFTERNOON.  STRONG DEEP LAYER WIND
FIELDS AND SHEAR VECTORS ORIENTED ACROSS THE COLD FRONT FROM THE
COLD SIDE TO THE WARM SIDE WOULD APPEAR TO FAVOR DISCRETE SUPERCELLS
ALONG THE COLD FRONT ACROSS WI/MI THIS AFTERNOON. 
HOWEVER...EXPECTED STORM MOTIONS ROUGHLY MATCH THE MOTION OF THE
SURFACE COLD FRONT.  THE COMBINATION OF STORMS REMAINING IN THE
FRONTAL ZONE...STRONG LINEAR FORCING...AND A NARROW INSTABILITY
CORRIDOR SHOULD INSTEAD FAVOR SQUALL LINE DEVELOPMENT WITH DAMAGING
WINDS AS THE PRIMARY THREAT.  THE DAMAGING WIND THREAT WILL DEVELOP
BY EARLY AFTERNOON ACROSS WI/WRN UPPER MI...AND THEN SPREAD SEWD
ACROSS LOWER MI/NRN IL/NRN INDIANA BY LATE THIS EVENING.

FARTHER S...SCATTERED THUNDERSTORMS WILL BE POSSIBLE INVOF THE WEAK
LOW-MID LEVEL BAROCLINIC ZONE AND AXIS OF MODERATE INSTABILITY FROM
THE IA/MO BORDER AREA EWD ACROSS CENTRAL/NRN IL AND INDIANA TO WRN
OH THIS AFTERNOON.  MLCAPE VALUES AROUND 1500 J/KG AND 0-6 KM BULK
SHEAR OF 30-40 KT MAY SUPPORT SUPERCELLS CAPABLE OF PRODUCING AT
LEAST ISOLATED LARGE HAIL AND DAMAGING GUSTS.

...ATLANTIC COAST AREA...
MORNING SOUNDINGS SHOW MOIST PROFILES WITH THE POTENTIAL FOR
MODERATE INSTABILITY THIS AFTERNOON FROM FL NWD TO THE MID ATLANTIC
REGION...WITH LESSER INSTABILITY FARTHER N INTO NY. 
MEANWHILE...DEEP LAYER VERTICAL IS MODEST FROM THE MID ATLANTIC TO
NY...AND WEAK FARTHER S ACROSS THE CAROLINAS/FL.  LOCAL TERRAIN
FEATURES AND SUBTLE SURFACE BOUNDARIES/SEA BREEZE CIRCULATIONS WILL
FOCUS THUNDERSTORM INITIATION THIS AFTERNOON...WITH THE POTENTIAL
FOR ISOLATED HAIL AND STRONG DOWNBURST WINDS.

...AZ RIM COUNTRY...
12Z SOUNDINGS ACROSS THIS AREA CONTINUE TO SHOW A NW FLOW REGIME
WITH THE POTENTIAL FOR MLCAPE OF 1500-2000 J/KG WITH DAYTIME
HEATING.  THE PERSISTENT MID LEVEL CYCLONIC SHEAR AXIS HAS DRIFTED A
LITTLE E OF ITS POSITION FROM THE PAST FEW DAYS...THUS THE STRONGER
STORMS /WITH THE POTENTIAL FOR ISOLATED LARGE HAIL AND STRONG
DOWNBURST WINDS/ MAY BE CONFINED MORE TO THE HIGHER TERRAIN THIS
AFTERNOON.

..THOMPSON/MEAD.. 08/18/2004

...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.