Severe Thunderstorm Warning 18, NWS Aberdeen, SD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
337 AM CDT SUN MAY 8 2005

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
EVERYTHING IS ON TRACK FOR ANOTHER ROUND OF SEVERE WEATHER IN THE
EASTERN FORECAST AREA THIS AFTERNOON. UPPER LOW IS CURRENTLY OVER
FAR WESTERN SD WITH DRY SLOT OVER THE FORECAST AREA EXTENDING N INTO
SRN ND. ABUNDANT SUNSHINE THIS MORNING WITH 700-500 MB LAPSE RATES
OF 7.5-8 C/KM AND DEW POINTS IN THE MID TO UPPER 50S WILL RESULT IN
MIXED LAYER CAPES FROM 1000-1900 J/KG ACROSS THE EAST BY 1 PM...WITH
MINIMAL CONVECTIVE INHIBITION BY THAT TIME. AS UPPER LOW PUSHES
EAST...BEST CHANCE FOR ORGANIZED/SEVERE STORMS WILL BE IN THE EAST
WHERE DEEP SHEAR OF AROUND 30KTS AND BROAD SCALE LIFT WILL BE
PRESENT. THE TS ACTIVITY WILL LIKELY BEGIN EARLIER THAN YESTERDAY.
THUNDERSTORMS WILL CHANGE OVER TO SHOWERS TONIGHT AS THE STACKED LOW
DRIFTS EAST ACROSS THE CWA. SHOWERS WILL STILL BE POSSIBLE ON MONDAY
WITH TROWAL FEATURE EVIDENT BEHIND LOW...MAINLY IN THE NORTHEAST.
COOLED TEMPS A BIT FOR MONDAY AS MAV GUIDANCE SEEMS A LITTLE WARM.
THE MET MAY BE TOO COOL HOWEVER. UPPER LEVEL RIDGE WILL MOVE IN
MONDAY NIGHT WITH WEAK SURFACE HIGH PRESSURE OVER THE AREA AS WELL.
AS RIDGE SHIFTS EAST...MODELS SHOWING MODERATE ISENTROPIC LIFTING
OCCURRING IN THE WEST...WITH SURFACE LOW OVER NEB/CO/KS TRIPLE PT.
ADDED SLIGHT CHANCE OF TS IN THE WEST ON TUESDAY AFTERNOON...BUT IT
MAY BE MORE SHOWERY LIKE THE NAM AND UKMET INDICATE. THE GFS HAS THE
WARM AIR MUCH FURTHER NORTH ON TUESDAY AND IS A LITTLE SUSPECT. KEPT
CHANCE OF PRECIP IN FOR  TUESDAY NIGHT AS ISENTROPIC LIFTING
CONTINUES.

.LONG TERM...WEDNESDAY THROUGH SATURDAY
MEDIUM RANGE MODELS CONTINUE TO ADVERTISE AN ACTIVE WEATHER PATTERN
FOR THE EXTENDED PORTION.  EXTENDED PERIOD OPENS WITH LARGE H5 LOW
OVER DESERT SOUTHWEST WITH TROUGH EXTENDING NORTH TO NEAR MONTANA.
SURFACE LOW IS TRAVELING IN SOUTHWEST FLOW AND INTERACTING WITH OLD
BOUNDARY LEFT OVER IN THIS COUNTRY.  THUNDERSTORMS LOOK LIKE A GOOD
BET TO START OF THE WEDNESDAY PORTION. GFS WOULD KEEP UP THIS
INTERACTION HOLDING A SURFACE REFLECTION JUST SOUTH OF STATIONARY
BOUNDARY AS UPPER LOW WEAKENS AND STARTS TO MOVE EAST.  EVEN BY 12Z
SATURDAY POSITIVE TILTED H5 TROUGH STILL HANGS BACK OVER FOUR
CORNERS AREA ALTHOUGH MUCH WEAKER THAN MID WEEK AND EVENTUALLY MOVES
EAST AS PACIFIC RIDGE STARTS PUSHING ONSHORE. TEMPERATURES LOOK COOL
BUT REASONABLE SO FEW CHANGES WERE MADE TO EITHER TEMPERATURES OR
WEATHER.

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

KNUTSVIG/KEEFE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ABERDEEN SD
1146 AM CDT SUN MAY 8 2005

MNZ039-046-SDZ005>008-010-011-017>023-036-037-051-091007-
BIG STONE-BROWN-BUFFALO-CLARK-CODINGTON-DAY-DEUEL-EDMUNDS-FAULK-
GRANT-HAMLIN-HAND-HYDE-MARSHALL-MCPHERSON-ROBERTS-SPINK-TRAVERSE-
1146 AM CDT SUN MAY 8 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

SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON ACROSS
THE AREA AHEAD OF A SLOW MOVING LOW PRESSURE SYSTEM. THE MAIN THREATS
ASSOCIATED WITH THE STORMS WILL BE LARGE HAIL AND DAMAGING WINDS. AN
ISOLATED TORNADO IS ALSO POSSIBLE. THE SEVERE THREAT WILL DIMINISH
AFTER SUNSET.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON.

SDZ003-004-009-015-016-033>035-045-048-091007-
CAMPBELL-CORSON-DEWEY-HUGHES-JONES-LYMAN-POTTER-STANLEY-SULLY-
WALWORTH-
1146 AM CDT SUN MAY 8 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF CENTRAL AND NORTH
CENTRAL SOUTH DAKOTA.

.DAY ONE...TODAY AND TONIGHT

AS A LOW PRESSURE SYSTEM SLOWLY MOVES EAST ACROSS SOUTH DAKOTA
TODAY...THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE AREA. WHILE
AN ISOLATED SEVERE STORM IS POSSIBLE...MOST OF THE STORMS ARE
EXPECTED TO REMAIN BELOW SEVERE LIMITS. LIGHTNING WILL BE THE MAIN
THREAT WITH THE STORMS TODAY...ACCOMPANIED BY SMALL HAIL AND GUSTY
WINDS. THUNDERSTORMS ARE EXPECTED TO GIVE WAY TO SHOWERS ACROSS THE
AREA TONIGHT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT.

TMT