Severe Thunderstorm Warning 38, NWS Aberdeen, SD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
424 AM CDT THU JUN 18 2009

.SHORT TERM...TODAY THROUGH SATURDAY
THUNDERSTORM CHANCES TODAY THROUGH TONIGHT....ALONG WITH THE
POSSIBILITY FOR SEVERE THUNDERSTORMS ARE THE FORECAST CHALLENGES.

A WARM FRONT...CURRENTLY SITUATED ACROSS SOUTHERN NEBRASKA...IS
EXPECTED TO LIFT NORTHEAST THIS AFTERNOON. BOUNDARY LAYER DEW
POINT INCREASE TO NEAR 70 DEGREES LATER THIS AFTERNOON...MAINLY IN
THE EXTREME SOUTHEASTERN CWA. IN THIS LOCATION...ML CAPE VALUES
INCREASE TO OVER 2200 J/KG...WITH 50 KNOTS OF 0-6KM SHEAR BY 0Z. A
WEAK MID LEVEL S/W WILL BE ENOUGH TO INITIATE CONVECTION...WITH
SEVERE STORMS CERTAINLY POSSIBLE. WITH THE SE CWA SO CLOSE TO THE
DAY 1 MODERATE RISK...HAVE ADDED SVR TO THE GRIDS IN THAT
LOCATION. THE CURRENT MCS MOVING ACROSS CENTRAL NEBRASKA MAY
INHIBIT THE NORTHWARD PROGRESSION OF THE WARM FRONT.

IN THE NORTHWEST...AN H7 TROF WILL MOVE INTO NORTH DAKOTA THIS
AFTERNOON. MODELS ARE TRYING TO DEPICT A DRY LINE TO MOVE ACROSS
NORTH DAKOTA AND NORTH CENTRAL SOUTH DAKOTA. THERE IS LITTLE SHEAR
IN THIS LOCATION...HOWEVER ML CAPE VALUES ARE AROUND 2000 J/KG.
EXPECT THUNDERSTORM TO DEVELOP WITH SOME OF THESE BECOMING STRONG.
ML CAPE VALUES QUICKLY WANE AFTER SUNSET...AND BELIEVE ANY STRONG
STORMS SHOULD DIE OFF AS WELL.

DRY AIR BEGINS TO INVADE THE NORTHERN PLAINS BY FRIDAY MORNING
WITH THE BOUNDARY LAYER BECOMING STABILIZED. THIS DRY AIR WILL PUSH
ACROSS THE ENTIRE CWA BY FRIDAY EVENING WITH A RATHER NICE DAY
EXPECTED ON SATURDAY. SOUTHERLY WINDS WILL INCREASE SATURDAY
AFTERNOON AHEAD OF THE NEXT WEATHER SYSTEM.

.LONG TERM...00Z SUNDAY THROUGH 12Z TUESDAY
MODELS ARE IN GENERAL AGREEMENT WITH OVERALL PATTERN THROUGH THE
LONG TERM PERIOD. THE REGION WILL BE IN SOUTHWEST FLOW ALOFT AS A
RESULT OF A WESTERN CONUS TROUGH. SEVERAL SHORTWAVES ARE PROGGED
TO RIDE THROUGH THIS FLOW WITH TIMING STILL UNCERTAIN AND POPS
ABUNDANT IN LONG TERM FORECAST. IT DOES APPEAR THAT THUNDERSTORM
DEVELOPMENT IS LIKELY SUNDAY INTO MONDAY. A MID LEVEL SHORTWAVE
PASSAGE COMBINED WITH INCREASING LOW LEVEL MOISTURE AND A WARM
FRONTAL BOUNDARY SHOULD BE ENOUGH TO INITIATE CONVECTION.
TEMPERATURES APPEAR TO BE SLIGHTLY ABOVE NORMAL FOR THIS TIME
PERIOD.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL. A FEW LINGERING SHOWERS AND
THUNDERSTORMS CONTINUE ACROSS THE AREA BUT WILL DISSIPATE
THROUGH THE MORNING HOURS. REDEVELOPMENT OF THUNDERSTORMS IS
EXPECTED THIS AFTERNOON.

&&

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

SHORT TERM...SD
LONG TERM...KRAMLICH
AVIATION...KRAMLICH

WEATHER.GOV/ABERDEEN

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ABERDEEN SD
158 PM CDT THU JUN 18 2009

MNZ039-046-SDZ003>011-015>023-034>037-191900-
TRAVERSE-BIG STONE-CORSON-CAMPBELL-MCPHERSON-BROWN-MARSHALL-
ROBERTS-WALWORTH-EDMUNDS-DAY-DEWEY-POTTER-FAULK-SPINK-CLARK-
CODINGTON-GRANT-HAMLIN-DEUEL-SULLY-HUGHES-HYDE-HAND-
158 PM CDT THU JUN 18 2009 /1258 PM MDT THU JUN 18 2009/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WEST CENTRAL
MINNESOTA...CENTRAL SOUTH DAKOTA...NORTH CENTRAL SOUTH DAKOTA AND
NORTHEAST SOUTH DAKOTA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

STRONG TO SEVERE THUNDERSTORM ARE POSSIBLE THIS AFTERNOON AND
INTO THE EARLY EVENING HOURS. THE MAIN THREAT FROM THESE STORMS IS
HIGH WINDS AND HAIL...HOWEVER ISOLATED TORNADOES MAY ALSO BE
POSSIBLE.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ON FRIDAY WITH NONE
EXPECTED TO BECOME SEVERE. AN ACTIVE WEATHER PATTERN RETURNS TO
THE AREA ON SATURDAY NIGHT...WITH THUNDERSTORM CHANCES PERSISTING
THROUGH MONDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING.

SDZ033-045-048-051-191900-
STANLEY-JONES-LYMAN-BUFFALO-
158 PM CDT THU JUN 18 2009 /1258 PM MDT THU JUN 18 2009/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL SOUTH
DAKOTA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

ISOLATED STORMS ARE POSSIBLE THIS AFTERNOON HOWEVER THEY ARE NOT
EXPECTED TO BE SEVERE.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ON FRIDAY WITH NONE
EXPECTED TO BECOME SEVERE. AN ACTIVE WEATHER PATTERN RETURNS TO
THE AREA ON SATURDAY NIGHT...WITH THUNDERSTORM CHANCES PERSISTING
THROUGH MONDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

CONNELLY

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
1042 AM CDT THU JUN 18 2009

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

0202 PM     TORNADO          12 SE SELBY             45.38N 99.86W
06/16/2009                   WALWORTH           SD   PUBLIC

            BRIEF TOUCHDOWN

&&

NWS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
141 PM CDT THU JUN 18 2009

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

0139 PM     HAIL             1 N MCLAUGHLIN          45.83N 100.81W
06/18/2009  E1.00 INCH       CORSON             SD   EMERGENCY MNGR

            HAIL THE SIZE OF QUARTERS COVERING THE GROUND.

&&

KGILLE