Severe Thunderstorm Warning 78, NWS Aberdeen, SD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
340 AM CDT MON JUN 20 2005

.SHORT TERM...TODAY THROUGH WEDNESDAY.

MAIN CONCERN IS CONVECTIVE CHANCES EACH DAY. DIFFICULT FORECAST AT
BEST WITH SURFACE BOUNDARY REMAINING IN OR NEAR THE FORECAST AREA
THROUGH THE SHORT TERM. THIS...ALONG WITH NOCTURNAL MCS ACTIVITY
WEST AND NORTH ADD MORE BOUNDARIES TO THE MIX.

CONVECTION CURRENTLY IN WESTERN SOUTH DAKOTA SHOULD SLOWLY MOVE
EAST...BUT SHOULD WEAKEN AS WELL AS UPPER TEMPERATURES VERY WARM.
ACARS SOUNDINGS SHOW +15 TO +17 NEAT H70...SO NO NEW CONVECTION
EXPECTED VERY EARLY THIS MORNING AND SLOW EROSION OF CURRENT SYSTEM
EXPECTED. IT WILL STILL AFFECT AT LEAST WESTERN FORECAST AREA THIS
MORNING. EXPECT MORE CONVECTION TO FIRE AGAIN TODAY WITH VERY WARM
TEMPERATURES AND PLENTY OF MOISTURE. SOME COOLING EXPECTED ALOFT AS
WELL MAINLY EASTERN AREA...SO NORTHERN AND EASTERN CWA SHOULD SEE
THUNDER. PREVIOUS FORECAST TIMING AND COVERAGE BASICALLY AGREED WITH
FOR TODAY.

BOTH NAM AND GFS NOW ADVERTISING VIGOROUS MCS TO MOVE THROUGH MAINLY
EASTERN FORECAST AREA MONDAY NIGHT INTO TUESDAY MORNING. BOTH 00
AND 06 UTC MODELS HAVE THIS SYSTEM...WITH FAIRLY SIMILAR TIMING.
INTRODUCED INCREASED POPS ON TUESDAY FOR THIS. WEDNESDAY STILL LOOKS
TO BE A DRY DAY...WITH ONLY SLIGHT CHANCES IN FAR EAST
OVERNIGHT...WHICH WERE IN PREVIOUS FORECAST.

TEMPS COULD BE TRICKY WITH CONVECTIVE DEBRIS LIMITING HEATING IN
SOME AREAS. GENERALLY WENT WITH SLIGHT WARMING ON TUESDAY OVER
PREVIOUS FORECAST AS SURFACE BOUNDARY ISNT AS FAR SOUTH OF AREA.
WEDNESDAY APPEARS TO BE THE WARMEST DAY IN THE SHORT TERM.

.LONG TERM...THURSDAY THROUGH SUNDAY

SURFACE TROUGH TO PASS THROUGH AREA THURSDAY UNDER 7H TEMPERATURES
OF +13-16 CELSIUS ACROSS CWA...SUPPRESSING ANY CHANCE FOR
CONVECTION. MODELS AGREE IN SOUTHERN CANADIAN TROUGH PASSING FRIDAY
RESULTING IN SIGNIFICANT HEIGHT FALLS OVER THE NORTHERN PLAINS.
THERMAL BOUNDARY BECOMES MORE EAST/WEST ORIENTED OVER THE DAKOTAS
THURSDAY NIGHT INTO FRIDAY. INSTABILITY CONTINUES TO INCREASE
THROUGH THE DAY FRIDAY WITH HEATING AND RETURN FLOW...AND WITH AN
UNCAPPED ENVIRONMENT...INTRODUCED POPS FOR FRIDAY INTO FRIDAY
EVENING ACROSS FORECAST AREA. CWA THEN INFLUENCED BY SOUTHWESTERLY
FLOW ALOFT AS BROAD UPPER RIDGE NUDGES EASTWARD AND CANADIAN TROUGH
MOVES OFF. H85 TEMPERATURES CLIMB ONCE AGAIN INTO THE LOWER 20S
CELSIUS BY 12Z SUNDAY. DGEX/GFSLR SHOW A SHORT WAVES PULLING
NORTHEASTWARD OUT OF THE CENTRAL ROCKIES ON THE FRONT SIDE OF THE
WESTERN CONUS TROUGH SOMETIME SATURDAY. THE TIMING ON THE SURFACE
WARM FRONT WITH THE RETURN FLOW IS UNCLEAR AT THIS POINT...ALONG
WITH THE STRENGTH OF THE CAP. THEREFORE...THE FORECAST WAS LEFT DRY
FOR SATURDAY AND SUNDAY.

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

&&

HARDING/LILES

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ABERDEEN SD
533 AM CDT SUN JUN 19 2005

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-201031-
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-
533 AM CDT SUN JUN 19 2005

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

...SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT...

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS EVENING AND
OVERNIGHT. SOME COULD BE SEVERE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

THUNDERSTORMS ARE AGAIN POSSIBLE MONDAY AFTERNOON AND NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED.

MOHR