Flash Flood Warning 7, NWS Aberdeen, SD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
855 PM CDT FRI JUN 24 2011

.UPDATE...
CURRENTLY MCS TAKING SHAPE ACROSS WESTERN SD...WITH DISCRETE
SUPERCELLS ASSOCIATED WITH DEVELOPING LINE. EXPECT LINE TO HOLD
TOGETHER ALTHO LATEST RUC SHOWS AN ABSENCE OF A DEVELOPING 850HPA
JET OVERNIGHT. CONCERN WILL TURN FROM CHC OF SEVERE TO POTENTIAL
OF HEAVY RAIN IN A SHORT PERIOD OF TIME FOR THE SWOLLEN MO RIVER
AREAS. CURRENT KUDX 88D ESTIMATED 1HR RAINFALL IS FROM 1.00 TO
1.50 INCHES. UPDATED ZONES A BIT EARLIER TO ACCOUNT FOR TSTORM
WATCH BOX...BUT ALL IN ALL CURRENT ZONES IN FINE CONDITION AND
ONLY HOURLY TEMP/DWPT/WIND TWEAKS HAVE BEEN NECESSARY.

UPDATED AVIATION DISCUSSION BELOW.

&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
THE POTENTIAL FOR SEVERE STORMS OVER THE NEXT COUPLE OF DAYS WILL
BE THE MAIN FORECAST CHALLENGE.

A BROAD UPPER LEVEL TROF OVER THE PAC NW WILL SLOWLY TRACK
EASTWARD THROUGH THE SHORT TERM. THIS TROF...ALONG WITH LLM WILL
RESULT IN THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS OVER
THE NORTHERN PLAINS THROUGH SUNDAY NIGHT.

AS OF 19Z A VIGOROUS SHORT WAVE IS TRACKING ACROSS WYOMING. THIS
SHORT WAVE WILL INTERACT WITH MODERATE INSTABILITY ACROSS THE
WESTERN DAKOTAS TO RESULT IN THUNDERSTORM DEVELOPMENT. CU IS
BEGINNING TO DEVELOP OVER THE BLACK HILLS WITH ADDITIONAL CU
DEVELOPING FARTHER WEST OVER WYOMING. WITH AN ESE STORM
MOTION...BELIEVE WHEN CONVECTION DEVELOPS OVER THE BLACK
HILLS...THEY SHOULD CLIP THE SW CWA. MODELS ARE SHOWING DECENT
CAPE VALUES IN THE HAIL GROWTH REGION WHICH SPC HAS PICKED UP ON
BY INCREASING THEIR DAY 1 HAIL OUTLOOK.

WHILE PCPN SHOULD EXIT THE CWA BY 12Z SATURDAY...A FEW MODELS ARE
KEEPING CONVECTION ACROSS THE EASTERN CWA THROUGH AT LEAST 15Z.
SINCE THIS IS NOT ENTIRELY IMPOSSIBLE WILL INCREASE POPS TO A LOW
END CHANCE FOR THE EASTERN CWA. BY LATE IN THE AFTERNOON ON
SATURDAY...A STRONGER MID LEVEL SHORT WAVE IS EXPECTED TO TRACK
ACROSS THE REGION. WHILE THE SURFACE BOUNDARY WILL BE SOMEWHAT
ILL- DEFINED...THERE WILL BE DECENT LIFT AND INSTABILITY TO RESULT
IN STRONG TO POSSIBLE SEVERE THUNDERSTORMS. THERE IS SOME TIMING
ISSUES BETWEEN THE NAM12 AND THE GFS WITH THIS SHORT WAVE...WITH
THE NAM BEING THE SLOWER OF THE TWO. WILL MAINTAIN HIGH END CHANCE
POPS ESPECIALLY FOR THE WESTERN HALF OF THE CWA BEGINNING AT 18Z.

CONVECTIVE PARAMETERS INCREASE SIGNIFICANTLY ON SUNDAY AHEAD OF A
COLD FRONTAL BOUNDARY. MODELS ARE IN A FAIR AGREEMENT WITH THE A FRONTAL
BOUNDARY BRING DRAPED ACROSS NE ND AND SOUTHWESTWARD TO SW SD
AROUND 18Z. DECENT MOISTURE CONVERGENCE ALONG THE FRONT WILL
RESULT IN THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WITH SOME
THUNDERSTORMS. ADD INTO THE MIX GOOD 0-1 KM SHEAR VECTOR VALUES
AND A HIGH SIGNIFICANT TOR PARAMETER LEADS THIS FORECAST TO
SUGGEST TORNADOES COULD BE POSSIBLE SUNDAY AFTERNOON. WHILE NOT
MENTIONED IN THIS FORECAST PACKAGE...WILL SUGGEST LATER FORECAST
SHIFT CONSIDER ADDING SEVERE MENTION SUNDAY.

.LONG TERM...MONDAY THROUGH FRIDAY
THE OPERATIONAL MODELS AND GFS ENSEMBLES ARE IN PRETTY GOOD
AGREEMENT THROUGH THE LONG TERM ACROSS THE UNITED STATES. AFTER AN
UPPER LEVEL LOW PRESSURE TROUGH PUSHES THROUGH ON MONDAY...THE
LARGE UPPER LEVEL HIGH PRESSURE AREA ACROSS THE SOUTHERN US WILL
EXPAND NORTHWARD INTO THE CENTRAL US INTO THE MIDDLE OF THE WEEK.
WILL KEEP IN THE SLIGHT CHANCE OF THUNDERSTORMS FOR MUCH OF THE
CWA FOR MONDAY AS THE UPPER LEVEL TROUGH MOVES ACROSS. MONDAY AND
TUESDAY WILL BE THE LAST BELOW NORMAL TEMPERATURE DAYS ACROSS THE
CWA AS SURFACE HIGH PRESSURE OUT WEST SLIDES ACROSS THE REGION. AS
THIS MOVES EAST...WARMER AIR WILL RETURN FOR WEDNESDAY AND
THURSDAY AS THE UPPER LEVEL HIGH PRESSURE AREA BUILDS OVER THE
REGION. THE WARMER AIR ALOFT WILL CAP OFF MUCH OF THE CWA FOR BOTH
WEDNESDAY AND THURSDAY FOR ANY THUNDERSTORM ACTIVITY. TEMPERATURES
WILL RISE TO ABOVE NORMAL WEDNESDAY AND THURSDAY INTO THE UPPER
80S TO THE LOWER 90S AND MAYBE EVEN WARMER WITH MOSTLY CLEAR
SKIES. THE MODELS CONTINUE TO SHOW A STRONG UPPER LEVEL LOW
PRESSURE TROUGH COMING OFF THE PACIFIC AND UP THE WESTERN SIDE OF
THE CENTRAL US RIDGE. THIS WILL BRING A CHANCE OF THUNDERSTORMS
FOR MAINLY THURSDAY NIGHT INTO EARLY FRIDAY ACROSS THE CWA. A COLD
FRONT BEHIND THIS TROUGH AXIS WILL ALSO BRING COOLER TEMPERATURES
FOR FRIDAY.

&&

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

DEVELOPING MCS ACROSS WESTERN SD WILL CONTINUE TO TREK EASTWARD
INTO THE KPIR AND KMBG AERODROMES WITHIN THE NEXT COUPLE OF HOURS.
CURRENTLY HAVE VCTS MENTION IN KMBG/KPIR TERMINAL FCSTS AND WILL
NEED TO AMEND ONCE TIME OF ARRIVAL IS A BIT MORE CERTAIN. HAVE
HELD OFF ON MENTION OF TSRA IN THE KABR AND KATY TERMINAL UNTIL
NEAR OR SHORTLY AFTER 06Z AND AGAIN WILL TWEAK ONCE TIME OF
ARRIVAL BECOMES MORE CERTAIN. ONCE LINE MOVES THROUGH RESPECTIVE
TAF SITES...EXPECTING CIGS TO CLIMB WITH NO WEATHER THEN EXPECTED
FOR THE REMAINDER OF THE TAF PERIOD.

&&

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

UPDATE...HINTZ
SHORT TERM...SD
LONG TERM...MOHR
AVIATION...HINTZ

WEATHER.GOV/ABERDEEN

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ABERDEEN SD
557 AM CDT FRI JUN 24 2011

SDZ003-004-009-015-016-033>036-045-048-051-251100-
CORSON-CAMPBELL-WALWORTH-DEWEY-POTTER-STANLEY-SULLY-HUGHES-HYDE-
JONES-LYMAN-BUFFALO-
557 AM CDT FRI JUN 24 2011 /457 AM MDT FRI JUN 24 2011/

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

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS ARE FORECAST TODAY INTO THIS EVENING. A COUPLE
THUNDERSTORMS MAY BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS
THIS AFTERNOON INTO THIS EVENING...MAINLY ALONG AND WEST OF THE
MISSOURI RIVER.

A FLOOD WARNING REMAINS IN EFFECT FOR ALL OF THE MISSOURI RIVER
WITHIN THIS FORECAST AREA...FROM THE NORTH DAKOTA AND SOUTH DAKOTA
BORDER ALL THE WAY DOWN TO CHAMBERLAIN. THE MISSOURI RIVER AT
PIERRE IS OVER SIX FEET ABOVE FLOOD STAGE...AND IS EXPECTED TO
REMAIN ABOVE FLOOD STAGE FOR THE NEXT SEVERAL WEEKS DUE TO HIGH
RELEASES OF WATER OUT OF GARRISON DAM IN NORTH DAKOTA AND OAHE DAM
NORTH OF PIERRE. SIGNIFICANTLY ELEVATED RIVER LEVELS UP AND DOWN
THE MISSOURI RIVER WILL CONTINUE.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THUNDERSTORMS ARE FORECAST SATURDAY AND SUNDAY. A FEW THUNDERSTORMS
MAY BECOME SEVERE EACH OF THESE TWO DAYS AS WELL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED LATER THIS AFTERNOON INTO THIS
EVENING ALONG AND WEST OF THE MISSOURI RIVER VALLEY.

MNZ039-046-SDZ005>008-010-011-017>023-037-251100-
TRAVERSE-BIG STONE-MCPHERSON-BROWN-MARSHALL-ROBERTS-EDMUNDS-DAY-
FAULK-SPINK-CLARK-CODINGTON-GRANT-HAMLIN-DEUEL-HAND-
557 AM CDT FRI JUN 24 2011

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

THUNDERSTORMS ARE POSSIBLE TODAY AND THIS EVENING...PRIMARILY
ALONG AND WEST OF THE JAMES RIVER VALLEY. SEVERE THUNDERSTORMS ARE
NOT EXPECTED AT THIS TIME.

AREAL FLOOD WARNINGS AND RIVER FLOOD WARNINGS CONTINUE DUE TO
RECENT EXCESSIVE RAINFALL. A NUMBER OF RIVERS...STREAMS...CREEKS
AND DITCHES ARE RUNNING AT OR ABOVE BANKFUL LEVELS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THUNDERSTORMS ARE FORECAST SATURDAY AND SUNDAY. A FEW THUNDERSTORMS
MAY BECOME SEVERE EACH OF THESE TWO DAYS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT.

DORN

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ABERDEEN SD
1003 PM CDT FRI JUN 24 2011

SDZ045-250345-
JONES-
1003 PM CDT FRI JUN 24 2011

...A SIGNIFICANT WEATHER ADVISORY HAS BEEN ISSUED FOR SOUTHERN JONES
COUNTY UNTIL 1045 PM CDT...

AT 957 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 14 MILES SOUTHWEST OF CAPA...OR 19 MILES
NORTHEAST OF KADOKA...MOVING EAST AT 45 MPH.

A FEW LOCATIONS IN THE ADVISORY INCLUDE OKATON...MURDO...WESTOVER AND
DRAPER.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 AM CDT
SATURDAY MORNING FOR NORTH CENTRAL SOUTH DAKOTA.

&&

HINTZ

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
1047 PM CDT FRI JUN 24 2011

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

1035 PM     TSTM WND DMG     15 W MURDO              43.89N 101.02W
06/24/2011                   JONES              SD   EMERGENCY MNGR

            SEMI BLOWN OVER ON INTERSTATE 90

&&

TEAM ABR