[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 210744
SWODY2
SPC AC 210742

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0242 AM CDT SAT AUG 21 2004

VALID 221200Z - 231200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 10 WNW
ANJ 25 NNW LNR 10 S RST 10 ESE MSP CMX.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 S DMN 20 NNW SVC
55 ENE INW U17 50 N BCE 10 W MLF 60 E TPH 30 SSW U31 40 NW U31 10 NE
WMC 85 SSE BNO 45 S RDM 35 ENE SLE 10 N BLI ...CONT... 65 NNW DVL 10
N JMS 65 NE ABR 35 E AXN 35 ENE ELO ...CONT... 45 NNE MTC SBN CMI 35
W EVV 10 WNW HOP 10 SE CSV HKY 25 ESE ECG.

...THERE IS A SLGT RISK OF SVR TSTMS OVER UPPER MI AND WI...

...UPPER GREAT LAKES INTO IA...
UPPER TROUGH CURRENTLY DROPPING SWD TOWARD NRN PARTS OF SASKATCHEWAN
AND MANITOBA IS FORECAST TO TURN EWD ACROSS ONTARIO TOMORROW AND
REACH WRN QUEBEC BY THE END OF THE PERIOD.  AN ASSOCIATED SURFACE
LOW IS EXPECTED TO MOVE EWD ACROSS ONTARIO DURING THE DAY BEFORE
LIFTING NEWD INTO CENTRAL QUEBEC SUNDAY NIGHT. SURFACE COLD FRONT
TRAILING SWWD FROM THE LOW WILL MOVE EWD ACROSS THE UPPER MS VALLEY
REACHING A LOWER MI/IA NEB LINE BY THE END OF THE PERIOD.  THIS
FEATURE IS EXPECTED TO PROVIDE A FOCUS FOR STRONG THUNDERSTORM
DEVELOPMENT.

MODELS INDICATE LOW LEVEL MOISTURE WILL INCREASE NWD AHEAD OF THE
COLD FRONT WITH SURFACE DEW POINTS IN THE MID 60S FROM PARTS OF
UPPER MI SWWD INTO IA AND ERN NEB.  PLUME OF STEEPER MID LEVEL LAPSE
RATES WILL EXTEND EWD FROM THE PLAINS TOWARD THE MS VALLEY AND
ENHANCE INSTABILITY WITHIN LOW LEVEL MOISTURE AXIS.  SBCAPE IS
FORECAST DURING THE AFTERNOON TO RANGE FROM 2500-3000 J/KG OVER IA
DECREASING NEWD TO 1000-1500 J/KG OVER NERN WI INTO UPPER MI.

A BAND OF STRONG STORMS MAY BE ONGOING EARLY IN THE PERIOD FROM WRN
UPPER MI INTO WRN WI IN ASSOCIATION WITH MID/UPPER LEVEL JET STREAK
MOVING ACROSS SRN ONTARIO.  THESE STORMS ARE EXPECTED TO CONTINUE
EWD DURING THE DAY WITH POTENTIAL TO PRODUCE STRONG WIND GUSTS AND
POSSIBLE HAIL. 

CONVECTION WILL BE SLOWER TO DEVELOP FARTHER SWWD ALONG THE COLD
FRONT UNTIL STRONG HEATING HELPS WEAKEN THE CAP BY LATE AFTERNOON OR
EVENING.  MODELS OFFER DIFFERENT SOLUTIONS CONCERNING CONVECTIVE
INITIATION...BUT THERE APPEARS TO BE SOME THREAT FOR STRONG/ISOLATED
SEVERE STORMS TO DEVELOP GIVEN MAGNITUDE OF PREDICTED INSTABILITY. 
GENERALLY WEAK WINDS ALOFT AND MINIMAL VERTICAL SHEAR WILL LIMIT
OVERALL SEVERE POTENTIAL.  

...MT INTO ND...
STRONG UPPER TROUGH IS FORECAST TO MOVE EWD ACROSS THE PACIFIC
NORTHWEST TOMORROW REACHING THE NRN INTERMOUNTAIN REGION BY 23/12Z. 
A SURFACE LOW IS EXPECTED TO MOVE EWD ACROSS MT WITH ELY LOW LEVEL
WINDS AHEAD OF THE LOW TRANSPORTING MARGINAL MOISTURE WWD INTO THE
REGION.  STRONG DYNAMIC FORCING AHEAD OF THE UPPER TROUGH COUPLED
WITH PRONOUNCED VERTICAL SHEAR WILL AID DEVELOPMENT OF STRONG
THUNDERSTORMS OVER CENTRAL MT BY MID AFTERNOON.  THIS ACTIVITY IS
EXPECTED TO SPREAD EWD TOWARD ERN MT DURING THE EVENING HOURS...AND
MOVE INTO ND DURING THE NIGHT AS LOW LEVEL JET AND ASSOCIATED WARM
ADVECTION INCREASE AFTER DARK. PRIMARY LIMITING FACTOR FOR SEVERE
STORMS WILL BE WEAK MOISTURE AND INSTABILITY.  HOWEVER...STRENGTH OF
DYNAMIC FORCING SUGGESTS THREAT FOR ISOLATED STRONG WIND GUSTS AND
HAIL WITH A FEW CELLS OVER MT...WITH THREAT TRANSITIONING TO
PRIMARILY SMALL HAIL DURING THE NIGHT AS CONVECTION BECOMES
INCREASINGLY ELEVATED NORTH OF THE SURFACE WARM FRONT.

..WEISS.. 08/21/2004

...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.