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000
FXUS63 KUNR 161719
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1119 AM MDT SUN JUN 16 2013

.UPDATE...
ISSUED AT 1109 AM MDT SUN JUN 16 2013

LARGE CLUSTER OF SHOWERS AND STORMS OVER WEST CENTRAL AND SOUTH
CENTRAL SOUTH DAKOTA CONTINUE TO SLOWLY SHIFT EAST THIS MORNING.
MOSTLY SUNNY SKIES IN PLACE ELSEWHERE AS HIGH PRESSURE NOSES IN
FROM THE NORTHWEST. EXPECT ADDITIONAL STORMS TO DEVELOP OVER
THE BLACK HILLS EARLY THIS AFTERNOON AND MOVE TO THE SOUTH AND
EAST. SOME STORMS COULD BE SEVERE ACROSS PARTS OF SOUTHWESTERN
SOUTH DAKOTA THIS AFTERNOON AS INSTABILITY AND SHEAR STILL LOOK
FAVORABLE. CURRENTLY LACKING A CLEAR KICKER TO GET THINGS
INITIATED THIS AFTERNOON...BUT IT SHOULDNT TAKE MUCH TO GET
SOMETHING GOING OFF THE HIGHER TERRAIN. UPDATES ARE OUT.

&&

.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 328 AM MDT SUN JUN 16 2013

CURRENT SURFACE ANALYSIS SHOWS WEAK HIGH PRESSURE OVER SD...WITH
LOW PRESSURE OVER THE SOUTHERN PLAINS. UPPER LEVEL ANALYSIS HAS
LOW PRESSURE OVER SOUTH CENTRAL CANADA...WITH ANOTHER AREA OF LOW
PRESSURE OFF THE PACIFIC NW COAST. ZONAL FLOW ALOFT IN PLACE
ACROSS OUR REGION. SKIES ARE MOSTLY CLEAR ACROSS THE AREA RIGHT
NOW WITH TEMPS IN THE UPPER 40S AND 50S. WINDS ARE LIGHT AND
VARIABLE. SHOWERS HAVE NOT DEVELOPED ACROSS WESTERN SD AS OF
09Z...BUT MID CLOUDS ARE INCREASING AND THE POTENTIAL IS STILL
THERE FOR DEVELOPMENT OVER THE NEXT COUPLE OF HOURS AS LOW LEVEL
JET STRENGTHENS OVER WESTERN NEB INTO SOUTHWESTERN SD AND STRONG
THETA-E ADVECTION REMAINS OVER THE AREA.

ZONAL FLOW WILL CONTINUE TODAY...WITH WEAK RIDGE THEN BUILDING OVER
THE REGION EARLY IN THE WEEK. THIS WILL KEEP TEMPS NEAR OR SLIGHTLY
ABOVE AVERAGE OVER THE NEXT COUPLE OF DAYS. ONGOING SHOWERS AND
STORMS ARE POSSIBLE THIS MORNING WITH LINGERING LOW LEVEL JET.
OTHERWISE...A WEAK COLD FRONT WILL DEVELOP AND SLIDE SOUTHEAST
THROUGH THE AREA LATE THIS MORNING AND AFTERNOON...AND COMBINED WITH
SUFFICIENT UPPER LEVEL SUPPORT WILL HELP TO PRODUCE SHOWERS AND
THUNDERSTORMS. SIGNIFICANT LOW LEVEL MOISTURE IS PROGGED TO BE IN
PLACE OVER SOUTHERN SD AHEAD OF THE FRONT...WITH CAPE VALUES PROGGED
NEAR 2000 J/KG THIS AFTERNOON. THERE WILL BE A SHARP CUTOFF TO THE
MOISTURE TOWARD NORTHERN SD AND NORTHEASTERN WY. THIS WILL LIMIT
BEST CHANCES FOR PCPN TO SOUTHERN SD...WHERE THERE IS ALSO A THREAT
FOR SEVERE STORMS...MAINLY DURING THE AFTERNOON. LARGE HAIL LOOKS TO
BE THE MAIN THREAT...BUT GUSTY WINDS ARE ALSO POSSIBLE...ESPECIALLY
LATER IN THE DAY. CHANCES FOR SHOWERS AND STORMS WILL SHIFT TOWARD
SOUTH CENTRAL SD BY THE EVENING AND SHOULD MOVE OUT/DISSIPATE BY
LATE EVENING AS FRONT SLIDES SOUTH OF THE CWA.

ON MONDAY...THE BETTER CHANCES FOR PCPN WILL SHIFT TO NORTHEASTERN
WY AND PORTIONS OF SOUTHWESTERN SD. WEAK HIGH PRESSURE MOVES ACROSS
THE NORTHERN PLAINS DURING THE DAY AND SOUTHEASTERLY WINDS INCREASE
OVER WESTERN AREAS...BRINGING INCREASING LOW LEVEL MOISTURE. WEAK
SHORTWAVE ENERGY WILL PASS OVER THE BUILDING RIDGE AND WILL LIKELY
BE ENOUGH TO GET AT LEAST ISOLATED SHOWERS AND STORMS GOING...
ESPECIALLY OVER THE BLACK HILLS AND THE HIGHER TERRAIN IN EASTERN
WY. THE THREAT FOR SEVERE STORMS IS NOT AS HIGH AS TODAY...BUT A
STRONGER STORM OR TWO CERTAINLY LOOKS POSSIBLE IN THE AFTERNOON.
HIGHS WILL MOSTLY BE IN THE 70S.

&&

.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 328 AM MDT SUN JUN 16 2013

UPPER RIDGE WILL BUILD INTO THE NRN PLAINS BY MID WEEK AS UPPER
LOW DIGS INTO THE PAC NW. WEAK WAVES WORKING THROUGH THE RIDGE
WILL RESULT IN A NEARLY DAILY CHANCE FOR ISOLATED TSTMS. UPPER
RIDGE AXIS SHIFTS EAST OF THE REGION BY LATE IN THE WEEK AS UPPER
LOW MOVES INTO THE NRN ROCKIES...WITH SOUTHWEST FLOW ALOFT
BRINGING BETTER CHANCES FOR TSTMS TO THE REGION. TEMPS WILL BE
NEAR TO SLIGHTLY ABOVE AVERAGE EXPECTED THROUGH THE PERIOD.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON
ISSUED AT 1109 AM MDT SUN JUN 16 2013

SCT TSTMS EXPECTED TODAY/TONIGHT...MAINLY FROM THE
BLKHLS INTO SW AND SCNTRL SD. STRONG AND ERRATIC WINDS ALONG WITH
HAIL POSSIBLE FROM THE TSTMS. OTHERWISE VFR CONDITIONS EXPECTED
THROUGH TONIGHT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...15
SHORT TERM...26
LONG TERM...7
AVIATION...JOHNSON