Severe Thunderstorm Warning 176, NWS Aberdeen, SD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
3 PM CDT MON AUG 23 2004

.SHORT TERM...TONITE THROUGH THURSDAY NITE
MAIN ISSUE THROUGH FORECAST PERIOD WILL BE CHANCE OF CONVECTION.
FOR TNT DECENT SYSTEM OVER INTERMOUNTAIN WEST WILL BE LIFTING INTO
SC CANADA...SPREADING UPPER LEVEL DIFFLUENCE AND LIFT ACROSS ABR
CWA.  MOISTURE CONTINUING TO SPREAD NORTH THIS AFTERNOON.  WITH
DEWPOINTS CLIMBING ABOVE 60 FOR MOST AREAS BY EARLY EVENING.
SCATTERED ACTIVITY ACROSS EAST THIS EVENING WILL LIKELY BE REPLACED
WITH MORE LINEAR STORMS LATE THIS EVENING AS AM EXPECTING MAIN
ACTIVITY TO DEVELOP OUT WEST AND SPREAD ACROSS CWA OVERNIGHT.
TUESDAY INTO TUESDAY EVE SHOULD BRING A RELATIVE LULL IN THE
ACTIVITY AS EFFECTIVE MOISTURE AND LL BOUNDARIES PUSH OFF EAST AND
SOUTH AND GRADUALLY DISSIPATE.  BUT MODERATE LLJ EXPECTED TO RETURN
TO CENTRAL/WESTERN SD LATE TUESDAY NIGHT AND MAY SEE SOME ACTIVITY
WITH THAT.  EMPHASIS ON WED AND THU SHOULD BE MAINLY OVER EASTERN
CWA WHERE BEST MOISTURE WILL RESIDE AND NOCTURNAL LLJ WILL BE
STRONGEST. TEMPS MODIFIED A BIT BUT WHEN ALL IS SAID AND DONE...THEY
HAVENT BEEN CHANGED TOO MUCH.

.LONG TERM...FRIDAY THROUGH MONDAY
MEDIUM RANGE MODELS HAVE SIMILAR TREATMENT FOR WEST COAST UPPER
TROUGH BUT DIFFER IN TIMING.  ECMWF EJECTS THE TROUGH TO THE
NORTHEAST INTO SOUTHERN CANADA ABOUT 24 HOURS FASTER THAN EITHER THE
GFS OR DGEX.  GFS AND DGEX VERY CLOSE THOUGH HAVE PRECIPITATION
TIMING VARIES BETWEEN 6 TO 12 HOURS.  OVERALL PATTERN SHOWS THE WEST
COAST UPPER TROUGH MOVING EAST INTO THE CENTRAL AND NORTHERN PLAINS
ACCOMPANIED BY A SURFACE FRONTAL SYSTEM.  MODEL QPF INDICATES
POTENTIAL FOR A MEASURABLE RAIN EVENT BEGINNING FRIDAY AND
PERSISTING INTO EARLY SATURDAY MORNING.  THE PRECIPITATION WILL
MOVE EAST ACROSS THE CWA WITH THE SURFACE COLD FRONT FRIDAY.  EXPECT
WRAP AROUND PRECIPITATION TO LINGER INTO EARLY SATURDAY AS THE
DEFORMATION SHIELD LIFTS TOWARD CANADA SATURDAY MORNING.  FOR NOW
KEPT SUNDAY AND MONDAY DRY THROUGH MODEL QPF HINTS THAT SHOWERS MAY
RETURN MONDAY.

SURFACE TEMPERATURES WILL COOL INTO THE 70S BEHIND THE COLD FRONT.
850 TEMPERATURES CONTINUE PAST TREND OF DIPPING INTO SINGLE DIGITS
EARLY IN THE EXTENDED PERIOD BEFORE RECOVERING BETWEEN 10-15C LATE
SUNDAY AND MONDAY WITH WEAK WARM AIR ADVECTION UNDER AN UPPER LEVEL
SHORTWAVE RIDGE.

&&
WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&

TDK/BM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ABERDEEN SD
500 AM CDT MON AUG 23 2004

MNZ039-046-SDZ008-020>023-240946-
BIG STONE-CODINGTON-DEUEL-GRANT-HAMLIN-ROBERTS-TRAVERSE-
500 AM CDT MON AUG 23 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF CENTRAL...NORTH
CENTRAL AND NORTHEAST SOUTH DAKOTA...AS WELL AS BIG STONE
AND TRAVERSE COUNTIES IN MINNESOTA.

.DAY ONE...TODAY AND TONIGHT

STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND NORTH OF A
WARM FRONT THAT WILL PUSH INTO CENTRAL SOUTH DAKOTA THIS AFTERNOON
AND PROGRESS EASTWARD INTO MINNESOTA TONIGHT. THERE IS A SLIGHT RISK
THAT SOME OF THESE STORM MAY BECOME SEVERE. THE MAIN THREAT OF ANY
SEVERE STORMS WILL BE LARGE HAIL AND DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THUNDERSTORMS ARE EXPECTED TO REDEVELOP AHEAD OF A SURFACE TROUGH
TUESDAY AFTERNOON IN EASTERN SOUTH DAKOTA AND WEST CENTRAL MINNESOTA.
THERE IS A SLIGHT RISK THAT A FEW OF THESE STORMS WILL BECOME SEVERE.
THE MAIN THREAT OF ANY SEVERE STORMS WILL BE LARGE HAIL AND DAMAGING
WINDS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING.

SDZ003>007-009>011-015>019-033>037-045-048-051-240946-
BROWN-BUFFALO-CAMPBELL-CLARK-CORSON-DAY-DEWEY-EDMUNDS-FAULK-HAND-
HUGHES-HYDE-JONES-LYMAN-MARSHALL-MCPHERSON-POTTER-SPINK-STANLEY-
SULLY-WALWORTH-
500 AM CDT MON AUG 23 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF CENTRAL...NORTH
CENTRAL AND NORTHEAST SOUTH DAKOTA...AS WELL AS BIG STONE
AND TRAVERSE COUNTIES IN MINNESOTA.

.DAY ONE...TODAY AND TONIGHT

STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND NORTH OF A
WARM FRONT THAT WILL PUSH INTO CENTRAL SOUTH DAKOTA THIS AFTERNOON
AND PROGRESS EASTWARD INTO MINNESOTA TONIGHT. THERE IS A SLIGHT RISK
THAT SOME OF THESE STORM MAY BECOME SEVERE. THE MAIN THREAT OF ANY
SEVERE STORMS WILL BE LARGE HAIL AND DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING.

LILES

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
250 PM CDT MON AUG 23 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0235 PM     HAIL             3 NE PIERPONT           45.53N 97.79W
08/23/2004  0.75 INCH        DAY                SD   PUBLIC

&&

HARDING

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
645 PM CDT MON AUG 23 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0625 PM     HAIL             5 NE BRANDT             44.72N 96.55W
08/23/2004  1.00 INCH        DEUEL              SD   PUBLIC

&&

TDK