Hail and Damaging Wind in Wyoming, July 9, 2004

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
240 PM MDT FRI JUL 9 2004

.DISCUSSION...20Z SFC ANALYSIS SHOWS ELONGATED HIGH PRESSURE AREA
FROM THE EASTERN DAKOTAS INTO CENTRAL KANSAS LEADING TO SOUTHERLY
RETURN FLOW OVER OUR CWA. TEMPERATURES WERE SLOW TO RISE IN THE
AREAS THAT WERE RAIN SOAKED EARLIER THIS WEEK...BUT NOW HAVE BEGUN
TO CATCH UP AS DIURNAL HEATING REACHES THE MAXIMUM. WEAK CONVERGENCE
ZONE EXISTS FROM THE NORTHERN BLACK HILLS INTO SOUTHEASTERN MONTANA
WITH SOME CU POPPING UP FOR A TIME THEN BEING KNOCKED BY DOWN BY THE
CAPPING INVERSION. WEST OF THE BOUNDARY OVER NE WYOMING DEWPOINTS
HAVE DROPPED INTO THE LOWER 30S TO LOWER 40S DUE TO WESTERLY
DOWNSLOPE WINDS...WITH DEWPOINTS IN THE UPPER 50S TO LOWER 60S EAST
OF THE BOUNDARY OVER WESTERN SOUTH DAKOTA.

FOR TONIGHT...WATER VAPOR IMAGERY SHOWS SHORTWAVE ENERGY ROTATING
TOWARD THE AREA FROM THE SOUTHWEST...WITH THUNDERSTORMS DEVELOPING
OVER THE HIGHER TERRAIN OF COLORADO AND WYOMING. EXPECT TO SEE SOME
OF THOSE STORMS MOVE INTO THE SOUTHWESTERN PORTIONS OF OUR CWA THIS
EVENING...WITH SOME STORMS POSSIBLY DEVELOPING OVER THE HIGHER
TERRAIN OF THE BLACK HILLS AS THE ENHANCED LIFT HELPS OVERCOME THE
CAP. WITH INCREASING SOUTHERLY WINDS AND LL JET OVER WESTERN SOUTH
DAKOTA...SHEAR MAY BE SUFFICIENT FOR A FEW SEVERE STORMS TO DEVELOP
THIS EVENING...THEN MOVE EAST/NORTHEAST ONTO THE PLAINS.

THROUGH THE WEEKEND...CWA REMAINS ON THE WESTERN EDGE OF A LARGE
SCALE UPPER RIDGE...PUTTING US UNDER THE PATH OF A SERIES OF
SHORTWAVES. THE STRONGEST WAVE AND BEST INSTABILITY WILL COME
TOGETHER ON SATURDAY AFTERNOON/EVENING FOR A BETTER CHANCE OF MORE
WIDESPREAD THUNDERSTORMS. EXPECT TSRA CHANCES THROUGH MONDAY.

UPPER RIDGE AXIS IS STILL FORECAST TO BE OVER THE NORTHERN PLAINS
FOR THE REST OF NEXT WEEK...LEADING TO DRY WEATHER WITH TEMPERATURES
NEAR OR ABOVE NORMAL. LATEST GFS RUN SHOWING A SHORTWAVE PASSING
THROUGH ON TUESDAY NIGHT/WEDNESDAY MORNING...LEADING TO
THUNDERSTORMS CROSSING THE AREA FROM NORTHWEST TO SOUTHEAST. WITH
THE RIDGE IN PLACE THE MOISTURE SOURCE IS IN QUESTION...SO WILL
LEAVE THE FORECAST DRY FOR NOW AND SEE WHAT SOLUTION LATER MODEL
RUNS BRING.

&&

UNR WATCHES/WARNINGS/ADVISORIES...
.SD...NONE.
.WY...NONE.

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
651 AM MDT FRI JUL 9 2004

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-101300-
BENNETT-BUTTE-CENTRAL BLACK HILLS-CUSTER CO PLAINS-FALL RIVER-HAAKON-
HARDING-HERMOSA FOOT HILLS-JACKSON-MELLETTE-NORTHEASTERN CROOK-
NORTHERN BLACK HILLS-NORTHERN CAMPBELL-NORTHERN FOOT HILLS-
NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-RAPID CITY-
SHANNON-SOUTHERN BLACK HILLS-SOUTHERN CAMPBELL-SOUTHERN FOOT HILLS-
SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP-
WESTERN CROOK-WESTON-WYOMING BLACK HILLS-ZIEBACH-
651 AM MDT (751 AM CDT) FRI JUL 9 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND
NORTHEASTERN WYOMING.

.DAY ONE...TODAY AND TONIGHT
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER FAR SOUTHWEST
SOUTH DAKOTA LATE THIS AFTERNOON AND EVENING. A WEAK UPPER LEVEL
DISTURBANCE WILL MOVE THROUGH THE REGION THIS EVENING...POSSIBLY
ASSISTING THUNDERSTORM DEVELOPMENT. LARGE HAIL WILL BE THE
MAIN THREAT WITH THESE STORMS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THUNDERSTORMS ARE FORECAST SATURDAY THROUGH MONDAY. THERE WILL BE A
SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE ENTIRE AREA SATURDAY.
THERE WILL BE A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTHWEST
SOUTH DAKOTA ON SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.