[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 171634
SWODY1
SPC AC 171632

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1132 AM CDT TUE AUG 17 2004

VALID 171630Z - 181200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 SW
MHN 20 S AIA 20 NNW BFF 40 W CDR 40 NNW CDR 30 S PHP 40 NNE VTN 40
ENE ANW 30 WNW BUB 30 SW MHN.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 ENE
JEF 40 NW COU 25 WSW IRK 10 W OTM 25 SSW MSN 35 NNE MKE MKG 20 NNE
AZO 30 SSE AZO 50 S SBN MTO 15 WNW BLV 25 ENE JEF.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 50 WNW CLE 25 N BNA
40 E MEM 55 E FSM 10 SSE FYV JLN 10 SSW CNU 30 W ICT 20 WNW HUT SLN
25 NNW TOP 15 ESE FNB 40 SSE OMA 30 E GRI 30 WNW AKO 20 NE COS 20 N
TAD 20 NE TCC 40 SSE MAF 30 NE DRT 30 N NIR 30 SW PSX ...CONT... 40
SE YUM 15 E DAG 10 NW TVL 20 SSW LMT 20 E CLM ...CONT... 55 ENE CTB
40 SE LWT 20 NNW 4BQ 50 SSW Y22 20 WSW MBG 50 WSW JMS 55 WNW JMS 55
NNW MOT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 SSE CEW 35 SW TYS
35 N TRI 15 NW DUJ 40 NW SYR ...CONT... 35 W EFK 25 WNW DOV 20 N RIC
40 N RWI ILM.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS CENTRAL/NRN IL AND
ADJACENT AREAS THIS AFTERNOON AND EVENING....

...THERE IS A SLGT RISK OF SVR TSTMS FOR THE NW NEB AREA THIS
EVENING....

...IL AREA THIS AFTERNOON INTO LATE THIS EVENING...
WATER VAPOR IMAGERY SHOWS A WEAK MID LEVEL SHORTWAVE TROUGH /NOW
OVER SW MN/ MOVING SEWD...AND THIS TROUGH WILL REACH NRN IL BY MID
AFTERNOON.  AT THE SURFACE...A TROUGH EXTENDS SW-NE FROM NE KS
ACROSS SE IA TO SE WI...WITH BOUNDARY LAYER DEWPOINTS IN THE 60S
SPREADING NEWD ACROSS NRN MO/IL TOWARD SW LOWER MI.  REGIONAL 12Z
SOUNDINGS SUGGEST THAT MLCAPE VALUES COULD APPROACH 2000 J/KG FROM
NE KS TO WRN/CENTRAL IL...WITH VALUES CLOSER TO 1000 J/KG AS FAR NE
AS SW LOWER MI.  THE COMBINATION OF LOW-LEVEL DESTABILIZATION...
WEAK LARGER SCALE ASCENT IN ADVANCE OF THE APPROACHING SHORTWAVE
TROUGH...AND A MESOSCALE BAND OF WEAK ASCENT ALONG THE WEAK SURFACE
TROUGH SHOULD SUPPORT SCATTERED THUNDERSTORMS THIS AFTERNOON FROM NE
MO TO SW LOWER MI.  30-40 KT WLY/NWLY FLOW IN THE 500-300 MB LAYER
WILL CONTRIBUTE TO AT LEAST MARGINALLY FAVORABLE SHEAR FOR
SUPERCELLS...GIVEN THE MODERATE INSTABILITY EXPECTED THIS AFTERNOON.
 THE STRONGEST STORMS MAY PRODUCE WIDELY SCATTERED LARGE HAIL AND A
FEW DAMAGING GUSTS BEFORE WEAKENING DURING THE LATE EVENING HOURS.

...NEB/SD AREA...
12Z MODELS CONTINUE THE TREND OF DEVELOPING A CLUSTER OF
THUNDERSTORMS THIS EVENING ACROSS NW NEB TO THE E OF A WEAK LEE
CYCLONE OVER SE WY.  THIS CONVECTION IS FORECAST TO SPREAD EWD OVER
NRN NEB AND SRN SD OVERNIGHT.  THE PRIMARY CONCERN THIS AREA WILL BE
THE DEGREE OF INSTABILITY.  REGIONAL 12Z SOUNDINGS...AS WELL AS
MODEL FORECAST SOUNDINGS...SUGGEST THAT MUCAPE VALUES MAY REACH
500-1000 J/KG...BUT WILL ULTIMATELY BE LIMITED BY BOUNDARY LAYER
DEWPOINTS OF AT BEST 50-55 F.  VERTICAL SHEAR SHOULD BE SUFFICIENT
FOR SUPERCELLS...AND THE STRONGEST STORMS MAY PRODUCE MARGINALLY
SEVERE HAIL GIVEN THE WEAK INSTABILITY.  OTHERWISE...ISOLATED
DAMAGING WIND GUSTS WILL ALSO BE POSSIBLE THIS EVENING GIVEN
RELATIVELY LARGE TEMPERATURE-DEWPOINT SPREADS AND INVERTED-V
PROFILES.

...NRN GREAT BASIN AREA...
A WELL-DEFINED MID LEVEL LOW IS DRIFTING EWD OVER NW UT.  A DEEP
MOISTURE PLUME WITH PW VALUES IN EXCESS OF 1 INCH COVERS MUCH OF
UT AND SRN ID...WHERE LOW-MID LEVEL LAPSE RATES ARE NEAR MOIST
ADIABATIC.  HOWEVER...LOCALLY STEEPER LAPSE RATES AND STRONGER
SURFACE HEATING WITHIN A MID LEVEL DRY SLOT COULD SUPPORT A FEW
STRONG STORMS WITH SMALL HAIL AND GUSTY WINDS ACROSS EXTREME NE
NV/SRN ID/NW UT TODAY.

...SE AZ AREA...
A BELT OF 30 KT NWLY MID LEVEL FLOW PERSISTS ON THE W SIDE OF A
NW-SE ORIENTED CYCLONIC SHEAR AXIS FROM NE AZ TO SW NM.  MODIFYING
THE 12Z AZ SOUNDINGS FOR DAYTIME HEATING YIELDS MLCAPE NEAR 1500
J/KG THIS AFTERNOON.  WEAK SELY LOW-LEVEL FLOW BENEATH THE NWLY MID
LEVEL FLOW MAY SUPPORT ISOLATED STRONG/SEVERE STORMS WITH MARGINAL
SUPERCELL CHARACTERISTICS THIS AFTERNOON.  THE STRONGEST STORMS MAY
PRODUCE MARGINALLY SEVERE HAIL OR STRONG OUTFLOW WINDS INVOF THE
MOGOLLON RIM.

..THOMPSON/CROSBIE.. 08/17/2004

...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.