Hail and Damaging Winds in South Dakota, August 7, 2007

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
955 AM MDT TUE AUG 7 2007

.DISCUSSION...A COUPLE AREAS OF WEAK CONVECTION ARE LINGERING INTO
THE MID MORNING HOURS ACROSS NORTHEAST WYOMING AND WESTERN SOUTH
DAKOTA THIS MORNING. THESE ARE TESTIMONY TO THE PRESENCE OF PLENTY
OF MOISTURE THROUGHOUT THE COLUMN... SOME CONTINUED WEAK INSTABILITY
...EVEN DURING THE EARLY HOURS OF THE DAY...AND SOME WEAK UPPER
LEVEL SHORT WAVES CROSSING THE AREA. THE CURRENT EXPECTED TIMING OF
THE WEAK SHORT WAVES CROSSING THE FORECAST AREA MIGHT NOT PROVIDE
THE BEST SHEAR DURING THE MOST INTENSE CONVECTION ACTIVITY DURING
THE MID AFTERNOON HOURS. THE CELLS MOVING INTO EAST CENTRAL WYOMING
THIS MORNING INDICATE SOME UVV ENHANCEMENT JUST AHEAD OF A WEAK
SHORT WAVE CURRENTLY MOVING THROUGH NORTH CENTRAL WYOMING. THIS
IMPULSE COULD EASILY MOVE THROUGH MOST OF WESTERN SOUTH DAKOTA
BEFORE MAX HEATING RESULTING IN A BRIEF BREAK IN THE ACTION. MOST OF
THE NEXT ROUND OF ACTIVE CONVECTION WOULD THEN BE DELAYED UNTIL THE
NEXT STRONGER UPPER IMPULSE MOVES THROUGH SOMETIME LATER THIS
EVENING AND BE FOCUSED OVER THE NORTHWEST CORNER AND SOUTHWEST
CORNER OF SOUTH DAKOTA.

&&

.AVIATION...VFR CONDITIONS EXPECTED THIS MRNG. A FEW STORMS WILL
DEVELOP IN THE AFTN/EVE HOURS AND MAY PRODUCE ISOLATED AREAS OF MVFR
CONDITIONS.

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
630 AM MDT TUE AUG 7 2007

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-081300-
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-
630 AM MDT (730 AM CDT) TUE AUG 7 2007

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

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER NORTHEAST WYOMING ALONG
WITH WESTERN AND SOUTH CENTRAL SOUTH DAKOTA THIS AFTERNOON AND
EVENING. THERE IS A SLIGHT RISK THAT SOME OF THESE THUNDERSTORMS MAY
BECOME SEVERE. LARGE HAIL AND STRONG WIND GUSTS WILL BE THE MAIN
THREATS.

THE GRASSLAND FIRE DANGER INDEX WILL BE IN THE EXTREME CATEGORY
TODAY FOR MANY PORTIONS OF THE WESTERN SOUTH DAKOTA PLAINS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THUNDERSTORMS ARE POSSIBLE AGAIN ON WEDNESDAY AND ON THURSDAY.
THERE IS THE POTENTIAL THAT A FEW OF THE STORMS MAY BECOME SEVERE
ON WEDNESDAY...PARTICULARLY OVER SOUTH CENTRAL SOUTH DAKOTA. LARGE
HAIL AND DAMAGING WIND GUSTS WILL BE THE MAIN THREATS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY AND TONIGHT.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
108 PM MDT TUE AUG 7 2007

SDZ012-025-072000-
BUTTE-NORTHERN FOOT HILLS-
INCLUDING THE CITIES OF...BELLE FOURCHE RESERVOIR...FRUITDALE...
NEWELL AND NISLAND
108 PM MDT TUE AUG 7 2007

.NOW...
...THUNDERSTORMS MOVING INTO THE AREA...

AT 101 PM MDT...A THUNDERSTORM WAS LOCATED 5 MILES NORTH OF SAINT
ONGE...OR ABOUT 8 MILES SOUTHEAST OF BELLE FOURCHE...MOVING EAST AT 5
MPH. ANOTHER THUNDERSTORM WAS DEVELOPING NEAR BELLE FOURCHE.

THIS STORMS WILL AFFECT BELLE FOURCHE...BELLE FOURCHE
RESERVOIR...SAINT ONGE...FRUITDALE...NISLAND...AND VALE.

SMALL HAIL...WIND GUSTS TO 40 MPH...AND FREQUENT CLOUD-TO-GROUND
LIGHTNING CAN BE EXPECTED.

CALDERON