Severe Thunderstorm Warning 191, NWS Aberdeen, SD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
315 PM CDT FRI SEP 10 2004

.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
MAIN FORECAST CONCERN IS PRECIPITATION CHANCES TONIGHT AND AGAIN ON
MONDAY. COLD FRONT CURRENTLY LOCATED FROM THE NORTHEAST CORNER TO
THE SOUTHWEST CORNER OF THE CWA AND PROGRESSING SLOWLY TO THE SOUTH
AND EAST. NOT A LOT OF CLOUD COVER ALONG THE NORTHERN PORTION OF THE
FRONT...BUT SOME BEGINNING TO PUSH IN FROM THE SOUTH IN ASSOCIATION
WITH A SHORTWAVE TRACKING ACROSS NORTHWESTERN NEBRASKA. THIS WAVE IS
FORECAST TO SLIDE NORTHEAST ACROSS EASTERN SOUTH DAKOTA THIS
EVENING. SOME THUNDERSTORMS OCCURRING WITH THE WAVE ALONG THE FRONT
NOW...SO WILL KEEP THE CHANCE GOING ACROSS THE AREA TONIGHT...ENDING
IN THE WESTERN CWA BY 06Z. THE WAVE PUSHES EAST OF THE AREA LATE
TONIGHT...WITH AN UPPER RIDGE MOVING OVER THE PLAINS SATURDAY. WEAK
HIGH PRESSURE AT THE SURFACE SLIDES DOWN BEHIND THE EXITING FRONT AS
WELL. THE WESTERN PORTION OF THE FRONT BEGINS TO TRACK BACK INTO THE
AREA AS A WARM FRONT LATE SATURDAY...JUST REACHING THE WESTERN CWA
BY SUNDAY MORNING. IT THEN PUSHES EAST NORTHEAST ACROSS THE CWA
DURING THE DAY...AND WILL BE FOLLOWED BY A COLD FRONT LATE SUNDAY
NIGHT AND MONDAY. NOT EXPECTING ANY PRECIPITATION SATURDAY OR SUNDAY
WITH THE UPPER RIDGE IN PLACE...BUT A FAIRLY DECENT SHORTWAVE WILL
ACCOMPANY THE COLD FRONT LATE SUNDAY NIGHT AND MONDAY...BRINGING THE
CHANCE FOR PRECIPITATION BACK TO THE REGION. SOME INSTABILITY WITH
THE FRONTAL PASSAGE...SO WILL CARRY AS TRW TO START OFF...BUT
CONDITIONS STABILIZE QUITE A BIT BY MONDAY NIGHT WITH JUST SOME
LINGERING RAIN SHOWERS THEN EXPECTED.

TEMPERATURES LOOK TO BE RIGHT AROUND NORMAL ON SATURDAY...THEN
DECENT WAA SETS UP BEHIND THE WARM FRONT ON SUNDAY...WITH 80S
EXPECTED MOST AREAS. COOLED THINGS BACK DOWN AGAIN MONDAY WITH THE
COLD FRONT MOVING THROUGH AND MORE CLOUD COVER EXPECTED.

.LONG TERM...TUESDAY THROUGH FRIDAY
NOT TO MANY CHANGES IN THE EXTENDED FROM THE PREVIOUS FORECAST WITH
MODELS SHOWING GOOD RUN TO RUN CONSISTENCY. STILL LOOKS LIKE BROAD
UPPER LEVEL TROUGH OVER THE WESTERN/CENTRAL US TUESDAY INTO
WEDNESDAY WITH EMBEDDED SHORTWAVES CONTINUING TO TRACK THROUGH THE
REGION. TROUGH THEN DEEPENS TOWARD THE END OF THE PERIOD WITH
SOUTHWEST FLOW INTO THE AREA THROUGHOUT THE EXTENDED TERM. THEREFORE
KEPT ALL PREVIOUS MENTIONS OF PRECIPITATION WITH AN UNSETTLED
PATTERN TAKING SHAPE. DID ADD IN A CHANCE FOR THUNDER THURSDAY AS
THE 12Z GFS SHOWS SOMEWHAT COOLER THICKNESS VALUES OVER THE
AREA...WITH RELATIVELY SIMILAR 500MB HEIGHTS...ASSUMED SOME COOLING
IN THE LOWER LEVELS THUS DECREASING THE STRENGTH THE CAP. KEPT
TEMPERATURES SIMILAR AS WELL...WITH A PRETTY GOOD COOL DOWN COMING
FRIDAY BEHIND THE COLD FRONT. GFS SHOWS H85 TEMPS FALLING INTO THE
+4C TO +7C RANGE FRIDAY INTO FRIDAY NIGHT ACROSS THE CWA. COULD
THEREFORE SEE TEMPS FALLING BACK INTO THE MID TO UPPER 40S FRIDAY
NIGHT.

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

PARKIN/ALBRECHT

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ABERDEEN SD
515 AM CDT FRI SEP 10 2004

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-111015-
BIG STONE-BROWN-BUFFALO-CAMPBELL-CLARK-CODINGTON-CORSON-DAY-DEUEL-
DEWEY-EDMUNDS-FAULK-GRANT-HAMLIN-HAND-HUGHES-HYDE-JONES-LYMAN-
MARSHALL-MCPHERSON-POTTER-ROBERTS-SPINK-STANLEY-SULLY-TRAVERSE-
WALWORTH-
515 AM CDT FRI SEP 10 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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS SATURDAY THROUGH THURSDAY...

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT.