[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 171610
SWODY1
SPC AC 171608

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1108 AM CDT THU AUG 17 2006

VALID 171630Z - 181200Z

...THERE IS A SLGT RISK OF SVR TSTMS NERN WY/SERN MT EWD ACROSS SD
AND SRN ND......

...SERN MT/NRN WY EWD ACROSS DAKOTAS...
COLD UPPER TROUGH CURRENTLY CROSSING NRN ROCKIES PRECEEDED BY
MODERATE SWLY FLOW AT MID LEVELS ACROSS NRN PLAINS.  OVERNIGHT A
COLD FRONT MOVED EWD ACROSS ND AND CURRENTLY EXTENDS FROM NWRN MN
SWWD TO BLACK HILLS AND WWD ACROSS NRN WY. SURFACE LOW CENTRAL WY
SHIFTS EWD INTO SWRN SD BY EVENING WITH NELY FLOW ALLOWING LOW LEVEL
MOISTURE TO SPREAD INTO BIG HORN BASIN AND NERN WY. 

SURFACE HEATING COUPLED WITH THE UPSLOPE FLOW TO NORTH OF FRONTAL
ZONE WILL SUPPORT STRONG/SEVERE THUNDERSTORM DEVELOPMENT FROM BIG
HORN BASIN ENEWD ACROSS NERN WY/SERN MT INTO NWRN SD/SWRN ND BY
MID/LATE AFTERNOON.  SHEAR PROFILES WILL INCREASE TOWARD EVENING AS
UPPER TROUGH APPROACHES AND LOW LEVEL JET TO S OF FRONTAL ZONE
ACROSS NRN HIGH PLAINS INCREASES TO 25-30KT. SUPERCELLS WILL BECOME
MORE LIKELY BY EVENING WITH THE INCREASINGLY FAVORABLE SHEAR AND
UPWARD MOTION AHEAD OF THE APPROACHING TROUGH.

PRIMARY THREAT WILL BE LARGE HAIL EARLY IN STORM EVOLUTION. 
DAMAGING WINDS WILL BECOME MORE LIKELY TOWARD EVENING AS STORMS
DEVELOP UPSCALE INTO POSSIBLE MCS AND SHORT LINES. ANY TORNADO
THREAT WITH SUPERCELLS SHOULD BE BRIEF AS BASES WILL BE RELATIVELY
HIGH AND MLCAPES LIKELY NOT MUCH ABOVE 1500 J/KG. 

THREAT OF AT LEAST DAMAGING WINDS EXPECTED TO CONTINUE WELL AFTER
DARK ACROSS DAKOTAS GIVEN THE UPPER WIND MAX TRANSLATING EWD ALONG
ND/CANADA BORDER.

..HALES/GUYER.. 08/17/2006