Severe Thunderstorm Warning 97, NWS Rapid City, SD

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
240 PM MDT MON AUG 5 2002

MAJOR CHANGES OCCURRING IN THE LARGE SCALE PATTERN LATE THIS WEEK.
THE WEST COAST TROUGH IS FORECAST TO OPEN UP AND MOVE EAST...THE
CENTRAL U.S. RIDGE IS SHOVED SOUTHWEST AND A MAJOR TROUGH IS
ESTABLISHED OVER CENTRAL NORTH AMERICA. AS THE WEST COAST TROUGH
CONTINUES TO WEAKEN A NUMBER OF SMALL IMPULSES WILL BREAK OFF AND
TRACK ACROSS THE NORTHWESTERN AND NORTH CENTRAL STATES DURING THE
NEXT TWO DAYS.  HOWEVER THE MAJOR PUSH OF COLDER AIR WONT OCCUR IN
THE NORTHLAND UNTIL EARLY NEXT WEEK.

TONIGHT...A WEAK MID LEVEL SYSTEM WILL MOVE OUT OF CENTRAL WYOMING
THIS EVENING AND INTO WESTERN SOUTH DATKOTA TONIGHT PRODUCING
WIDESPREAD RAIN...AND SOME LOCALLY HEAVY THUNDERSHOWERS. THE AMS IS
VERY MOIST BUT SHEAR AND UPPER LEVEL DYNAMICS ARE WEAK SO THE
POTENTIAL FOR SEVERE WEATHER IS MINIMAL BUT PRESENT. CAPES ARE IN
THE NEIGHBORHOOD OF 1000 EARLY THIS EVENING.

TUESDAY AND TUESDAY NIGHT...AS THE SHORT WAVE EXITS THE
AREA...THUNDERSTORM ACTIVITY IS EXPECTED TO BE CONCENTRATED IN THE
ERN PART OF THE CWFA WITH MINIMAL CONVECTION OVER NERN WY AND THE
REGION AROUND THE BLACK HILLS.

WEDNESDAY THROUGH FRIDAY...THE WEST COAST TROUGH BEGINS TO BREAK UP
AND THE PIECES EXIT THROUGH THE NORTHERN STATES DURING THIS TIME.
THE AVN MODEL SEEMS TO HAVE OVERDEVELOPED AN H5 LOW OVER THE SWRN
CRNR OF SD. THE ASSCD PCPN FIELDS ARE PROBABLY MUCH OVERDONE.  WILL
JUST KEEP A CHC OF TSTMS IN THE PACKAGE TO THIS TIME PERIOD. DETAILS
ARE A LITTLE TOUGH TO IRON OUT THIS FAR IN ADVANCE.

SATURDAY THROUGH MONDAY...A MOSTLY DRY WEST TO NORTHWEST FLOW SHOULD
KEEP THINGS PRETTY QUIET AND MILD.

.UNR...NONE.

CARPENTER