Flash Flooding and Hail in South Dakota, June 19 to 20, 2013

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
827 PM CDT WED JUN 19 2013

.UPDATE...
NO MAJOR CHANGES EXPECTED TO THE FORECAST. FORECASTER CONFIDENCE
IS STILL HIGH ENOUGH TO KEEP THUNDERSTORMS IN THE EAST. SUSPECT
DEVELOPING LLJ AND MOIST/UNSTABLE ATMOSPHERE PER ABR EVE RAOB SHOULD
ALLOW FOR SOME STORMS OVERNIGHT. OUT WEST FORECASTER CONFIDENCE IS
LOWER. MID LEVEL HEIGHT RISES AND THERMAL RIDGING MAY HOLD MOST
ACTIVITY AT BAY. WILL CONTINUE TO EVALUATE AS THE EVENING
PROGRESSES. UPDATES ISSUED EARLIER TO BRING POPS DOWN OVER WESTERN
CWA.

&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
WEAK MID LEVEL WAVE MOVING THROUGH SD AT THIS TIME WITH VORT MAX
AND RIPPLE AT 500MB BEING OBSERVED. AS THIS WAVE CONTINUES TO MOVE
THROUGH THE REGION THROUGH THE EVENING...ISO/SCT SHOWERS AND
STORMS ARE EXPECTED TO DEVELOP. DEWPOINTS HAVE ACTUALLY DROPPED A
BIT INTO THE 50S THIS AFTERNOON AS BETTER MIXING DEVELOPS.
OBSERVED VALUES ARE A BIT UNDER FORECAST VALUES. MLCAPE VALUES
RANGE FROM ABOUT 500 J/KG ACROSS THE EASTERN COUNTIES TO AROUND
1500 J/KG OVER THE WESTERN CWA. ALTHOUGH...THE AREA WHERE THE
HIGHEST CAPE RESIDES THIS AFTERNOON IS IN THE REGION OF WEAK
SUBSIDENCE BEHIND THE MID LEVEL WAVE OVER SD. EXPECTING ANYTHING
THAT DEVELOPS THIS AFTERNOON WILL BE OVER THE EASTERN CWA IN
BETTER ASCENT AREA...BUT WILL HAVE TO DESTABILIZE JUST A BIT MORE.
CONVECTIVE MODE EXPECTED TO BE PULSE-TYPE DUE TO THE LACK OF
SHEAR TO SUSTAIN ANY ORGANIZED UPDRAFTS. ANY STRONGER CORES ARE
CAPABLE OF PRODUCING HEAVY RAIN OR SMALL HAIL. HI RES MODELS
INDICATING THIS WITH SCT ACTIVITY DEVELOPING OVER THE NEXT FEW
HOURS...WITH PERHAPS A BETTER CONSOLIDATION LATER THIS EVENING AS
THE LOW LEVEL JET STRENGTHENS.

REST OF THE SHORT TERM LOOKS ACTIVE WITH PRETTY GOOD CHANCES FOR
SEVERE WEATHER. BY THURSDAY AFTERNOON MLCAPE INCREASES TO OVER
2000 J/KG ACROSS THE EASTERN CWA WITH BETTER SHEAR VALUES THAN
WHAT IS OVER THE REGION TODAY. 0-6KM SHEAR INCREASES TO OVER 40
KNOTS BY 00Z FRIDAY. MODELS DO INDICATE THERE COULD BE SOME LEFT
OVER CLOUDINESS OR SHOWERS DURING THE DAY SO WILL HAVE TO SEE IF
THIS COMES INTO PLAY FOR AFTERNOON DESTABILIZATION. FRIDAY
AFTERNOON AND EVENING LOOKING IMPRESSIVE FOR SEVERE WEATHER AS
WELL. WARM FRONT SHARPENS UP JUST TO THE SOUTH OF THE REGION AND
MODELS WOULD SUGGEST THE CWA IS ON THE EDGE OF THE CAP. MLCAPE AND
SHEAR EVEN MORE IMPRESSIVE ON FRIDAY COMPARED TO THURSDAY AFTERNOON.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
THE LONG TERM IS SHOWING MORE OF A SUMMER PATTERN WITH
WARM AND MOIST AIR ALONG WITH GOOD INSTABILITY THROUGH MUCH OF
THE PERIOD. TO BEGIN THE PERIOD...SATURDAY AND SATURDAY NIGHT LOOK
TO BE THE MOST INTERESTING DEPENDING ON HOW ALL THINGS COME
TOGETHER. THE MODELS SHOW A STRONG UPPER LEVEL WAVE KICKING ACROSS
THE NORTHERN PLAINS AND INTO SOUTHERN CANADA THROUGH SUNDAY NIGHT.
THE MODELS SHOW DIFFERENCES IN TRACKING AND TIMING WITH THIS
SYSTEM ALONG WITH THE SURFACE FEATURES. ON SATURDAY...A SURFACE
LOW PRESSURE AREA WILL BE TO OUR SOUTH WITH A WARM FRONT EXTENDING
NORTHEAST INTO EASTERN SD. EVERYTHING LOOKS GOOD FOR A GOOD
CHANCE OF THUNDERSTORMS SATURDAY AFTERNOON AND NIGHT ALONG WITH
SEVERE WEATHER POSSIBILITIES. DEEP LAYER SHEAR...MOISTURE...
INSTABILITY...A LOW LEVEL FOCUS MECHANISM ALONG WITH BROAD SCALE
UPPER LEVEL LIFT WILL ALL BE IN PLACE ON SATURDAY AND SATURDAY
NIGHT. THE INHIBITING FACTOR MAY BE WARM MID LEVEL TEMPERATURES
AND WHERE THESE SETUP. NONETHELESS...EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP AND LIFT NORTHWARD. AS THE SURFACE LOW
PRESSURE AREA MOVES NORTH AND A COOL FRONT/DRYLINE PUSHES IN
BEHIND THROUGH SUNDAY. THIS MAY ALSO BE A FOCUS FOR MORE
CONVECTION INTO SUNDAY EVENING.

THE ACTIVE PATTERN CONTINUES THROUGH THE MIDDLE OF THE WEEK AS NEW
LARGE SCALE TROUGHING DEVELOPS OFF THE WEST COAST AND INLAND. THIS
WILL SEND OFF SEVERAL SHORT WAVE TROUGHS THROUGH WEDNESDAY
BRINGING SEVERAL CHANCES OF SHOWERS AND STORMS. THE MODELS SHOW
THE NEXT SIGNIFICANT SHORT WAVE TO COME ACROSS THE REGION MONDAY
AFTERNOON THROUGH TUESDAY AFTERNOON. TEMPERATURES THROUGH THE
PERIOD WILL BE MOSTLY IN THE 80S AND LOWER 90S WITH LOWS IN THE
60S.

&&

.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

A FEW THUNDERSTORMS ARE EXPECTED TO POP UP ACROSS THE REGION THIS
EVENING AND OVERNIGHT. FIRST IN THE EAST AROUND KABR/KATY...AND
THEN LATER AROUND KPIR/KMBG. OTHERWISE VFR CONDITIONS ARE EXPECTED
UNTIL TOWARD MORNING. AT THAT TIME SOME MODEL DATA INDICATES THE
POTENTIAL FOR MVFR CIGS SPREADING ACROSS THE REGION. FORECASTER
CONFIDENCE ONLY MEDIUM ON THAT PROGNOSTICATION.

&&

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

UPDATE...TDK
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...TDK

WEATHER.GOV/ABERDEEN

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ABERDEEN SD
407 AM CDT WED JUN 19 2013

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-200915-
TRAVERSE-BIG STONE-CORSON-CAMPBELL-MCPHERSON-BROWN-MARSHALL-
ROBERTS-WALWORTH-EDMUNDS-DAY-DEWEY-POTTER-FAULK-SPINK-CLARK-
CODINGTON-GRANT-HAMLIN-DEUEL-STANLEY-SULLY-HUGHES-HYDE-HAND-JONES-
LYMAN-BUFFALO-
407 AM CDT WED JUN 19 2013 /307 AM MDT WED JUN 19 2013/

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

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON...INITIALLY
DEVELOPING ACROSS SOUTH CENTRAL SOUTH DAKOTA AND MOVING NORTHEAST.
THERE MAY BE ISOLATED STRONG STORMS THIS AFTERNOON. ANOTHER ROUND
OF STRONG STORMS IS EXPECTED TO DEVELOP OVERNIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

AN UNSETTLED PATTERN CONTINUES THROUGH THIS WEEK...WITH SEVERAL
CHANCES FOR THUNDERSTORMS TO DEVELOP. SEVERE STORMS ARE POSSIBLE
ON THURSDAY AND THROUGH THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY AND TONIGHT.

SERR

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ABERDEEN SD
1035 PM CDT WED JUN 19 2013

SDZ006-010-200415-
BROWN-EDMUNDS-
1035 PM CDT WED JUN 19 2013

...A SIGNIFICANT WEATHER ADVISORY HAS BEEN ISSUED FOR EASTERN EDMUNDS
AND WESTERN BROWN COUNTIES UNTIL 1115 PM CDT...

AT 1031 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 7 MILES NORTHWEST OF WARNER...OR 9 MILES
SOUTHWEST OF ABERDEEN...MOVING NORTHEAST AT 25 MPH.

A FEW LOCATIONS IN THE ADVISORY INCLUDE ABERDEEN...RICHMOND LAKE REC
AREA AND WESTPORT.

SMALL HAIL...AND WINDS AROUND 40 TO 50 MPH ARE EXPECTED WITH THIS
STORM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS. IF YOU CAN HEAR
THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING.

&&

TDK

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ABERDEEN SD
1049 PM CDT WED JUN 19 2013

SDZ008-021-200430-
GRANT-ROBERTS-
1049 PM CDT WED JUN 19 2013

...A SIGNIFICANT WEATHER ADVISORY HAS BEEN ISSUED FOR NORTHERN GRANT
AND SOUTHEASTERN ROBERTS COUNTIES UNTIL 1130 PM CDT...

AT 1045 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR MARVIN...OR 12 MILES WEST OF MILBANK...
MOVING NORTHEAST AT 10 MPH.

A FEW LOCATIONS IN THE ADVISORY INCLUDE CORONA AND WILMOT.

SMALL HAIL...AND WINDS AROUND 40 TO 50 MPH ARE EXPECTED WITH THIS
STORM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS. IF YOU CAN HEAR
THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING.

&&

TDK