Tornado and Hail in South Dakota, July 24 to 25, 2002

AREA FORECAST DISCUSSION FOR CENTRAL/N-EAST SD AND W-CENTRAL MN
NATIONAL WEATHER SERVICE ABERDEEN SD
345 PM CDT WED JUL 24 2002

GOOD S/W AND JET STREAK WILL DROP SE INTO AND ACROSS THE ABR CWA
THROUGH TONIGHT. THESE FEATURES WILL INTERACT WITH GOOD LL
MOISTURE...A WEAK CAP...INCREASING INSTABILITY...A GOOD WS
PROFILE...ALONG WITH WAA/LL CONVERGENCE ALONG AND NEAR A WARM FRONT
ACROSS NE SD AND WC MN...TO BRING A GOOD CHANCE OF TSRAS TO THIS
AREA. ABR AND UNR RADARS ALONG WITH SATELLITE ALREADY SHOWING
DEVELOPMENT ACROSS NW AND NC SD LATE THIS AFTN. THIS SHOULD CONTINUE
TO MOVE SE AND BEGIN TO TAP INTO BETTER MOISTURE...INSTABILITY AND
FAVORABLE WS THIS EVENING ACROSS NE SD AND WC MN. THIS ACTIVITY
SHOULD ALL MOVE EAST AND OUT OF THE AREA BY MIDNIGHT LEAVING CLEAR
TO P/C SKIES OVER THE AREA. WINDS ARE ALL EXPECTED TO BECOME NW. ON
THURS...THE MDLS SHOW A WK S/W SLIDING SE ACROSS NE SD AND WC MN IN
THE AFTN AND EVENING. THEREFORE...WILL PUT IN A POP ACROSS THIS
AREA. THE REST OF THE CWA SHOULD SEE M/S SKIES WITH SOME HOT TEMPS
ACROSS THE AREA. THE WINDS WILL BE FROM THE NW AT 10 TO 20 MPH.
DRIER AIR WILL ALSO MOVE INTO THE AREA THURS AND THURS NIGHT. THURS
NIGHT SHOULD BE CLEAR TO P/C WITH SFC HIGH PRES BUILDING EAST. IT
WILL ALSO BE A COOL NIGHT WITH LOWS MOSTLY IN THE 50S. THE MDLS SHOW
S/WS AFFECTING THE CWA FRI AND FRI NIGHT AND AGAIN SAT NIGHT.
THEREFORE....WILL GO WITH A 30 POP FOR THESE TIME PERIODS AND P/C
SKIES.

.EXTENDED DISCUSSION...

MAIN CONCERN FOR THE EXTENDED WILL BE THE CHANCE FOR PRECIPITATION
EARLY. AN UPPER LOW WILL BE OVER SOUTH CENTRAL CANADA SUNDAY MORNING
WITH A TROUGH EXTENDING BACK TO THE NORTHERN ROCKIES. A COLD FRONT
WILL BE JUST EAST OF THE REGION WITH THE INDICATION OF SOME SHOWERS
AND THUNDERSTORMS LINGERING BEHIND IT DURING THE MORNING HOURS. THE
SOUTHERN PORTION OF THE UPPER TROUGH PUSHES ACROSS THE UPPER MIDWEST
ON MONDAY...BUT HIGH PRESSURE AT THE SURFACE WILL ALREADY BE MOVING
IN BEHIND THE EXITING FRONT...SO WILL KEEP DRY. THE SURFACE HIGH
THEN BECOMES THE DOMINANT FEATURE DURING THE REMAINDER OF THE
PERIOD...SO NO PRECIP EXPECTED. H85 TEMPS WILL BE MILD FOR MOST OF
THE PERIOD...MAINLY IN THE TEENS...BUT SOME RISE NOTED TOWARD
WEDNESDAY WHEN AN UPPER RIDGE BEGINS TO BUILD WEST OF THE AREA.
TEMPS GENERALLY WILL BE BELOW NORMAL...POSSIBLY REACHING NEAR NORMAL
ON WEDNESDAY.

.ABR...NONE

MOHR/PARKIN