Severe Thunderstorm Warning 245, NWS Sioux Falls, SD

000 
WWUS53 KFSD 282208
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
507 PM CDT TUE AUG 28 2007

IAC035-282230-
/O.CON.KFSD.SV.W.0245.000000T0000Z-070828T2230Z/
CHEROKEE IA-
507 PM CDT TUE AUG 28 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM CDT
FOR SOUTHERN CHEROKEE COUNTY...

AT 507 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED 4 MILES WEST OF WASHTA...OR ABOUT 23 MILES NORTHWEST OF IDA
GROVE...MOVING EAST AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
   QUIMBY AROUND 515 PM CDT...

THIS STORM IS ALSO SHOWING STRONG ROTATION AS IT MOVES NORTH OF 
WASHTA. IT WILL PRODUCE LARGE HAIL AND DAMAGING WIND. GO INSIDE A 
STURDY BUILDING AND STAY AWAY FROM WINDOWS.

LAT...LON 4272 9587 4257 9587 4257 9540 4274 9541

$$

SCHUMACHER

000 
WWUS53 KFSD 282226
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
526 PM CDT TUE AUG 28 2007

IAC035-282236-
/O.EXP.KFSD.SV.W.0245.000000T0000Z-070828T2230Z/
CHEROKEE IA-
526 PM CDT TUE AUG 28 2007

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN CHEROKEE COUNTY
EXPIRES AT 530 PM CDT...

THE STORM IS NO LONGER SEVERE. HOWEVER...ADDITIONAL STORMS WILL 
BRING RAIN...LOCALLY HEAVY AT TIMES...TO THE AREA.

LAT...LON 4272 9587 4257 9587 4257 9540 4274 9541

$$

SCHUMACHER

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
319 PM CDT TUE AUG 28 2007

.DISCUSSION...
UPPER LEVEL SUBTROPICAL WAVE WILL CONTINUE TO SPREAD RAIN OVER
SOUTHWEST MINNESOTA AND NORTHWEST IOWA IN TO THE EARLY EVENING. SOME
SPOTTY THUNDERSTORM ACTIVITY WILL BE POSSIBLE THROUGH ABOUT 600 PM
CDT NEAR KSUX/KSLB AS FRONT SAGS SOUTH...BUT SEVERE IS NOT EXPECTED.
OTHERWISE...WEAK COLD ADVECTION SHOULD KEEP THINGS MIXED SLIGHTLY
TONIGHT...ALLOWING NORTH WINDS TO MAINTAIN ABOUT 5 TO 10 MPH.
GUIDANCE LOWS WERE IN LINE AND DID NOT CHANGE MUCH. ONE CONCERN
EARLY WILL BE TRYING TO SCOUR OUT LOW CLOUDS. BELIEVE SUBSIDENCE AND
WEAK COLD ADVECTION WILL SLOWLY RAISE CEILINGS THROUGH THE
NIGHT...EXPECT FOR THE FAR SOUTHERN CWA WHERE RESIDUAL MOISTURE IN
THE LOW LEVELS ALONG WITH A POTENTIALLY WEAKER WIND COULD RESULT IN
SOME FOG.

LOW CLOUDS WILL LINGER INTO TOMORROW MORNING ACROSS THE AREA BUT
PRECIP IS NOT EXPECTED. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY AS
LOW CLOUDS MOVE OUT. A FEW MORE CLOUDS MAY LINGER IN SOUTH CENTRAL
SOUTH DAKOTA. WHILE THE CLOUDS WILL KEEP TEMPS DOWN IN THE MORNING
IN NW IA...ENOUGH SUN AND DRY AIR TO ALLOW FOR FAIRLY EFFICIENT
MIXING ACROSS THE AREA. TEMPS WILL GENERALLY BE IN THE 70S. IT WILL
ALSO BE MUCH LESS HUMID AS AFOREMENTIONED MIXING AND DRY AIR
ADVECTION ALLOW DEW POINTS TO FALL INTO THE 40S WEST OF THE JAMES
RIVER.

THE DRY AIR AND CLEAR SKIES WILL ALLOW TEMPS TO PLUMMET ON WED
NIGHT. MANY LOCATIONS WILL FALL INTO THE 40S OVERNIGHT IN SW MN AND
ADJACENT AREAS OF NW IA AND SE SD.  RETURN FLOW BEGINS TO SET UP ON
THURSDAY WEST OF I29 WHICH WILL MEAN A SLOW RETURN IN DEW POINTS AND
A SLOW WARMING TREND. WINDS WILL ALSO SLOWLY INCREASE OUT OF THE
SOUTHEAST IN THESE AREAS.  THIS WARMING TREND AND SLOW INCREASE IN
MOISTURE AND WINDS WILL SLOWLY MOVE EAST ON FRIDAY.  TEMPERATURES ON
THURSDAY WILL START OUT NEAR SEASONAL NORMALS BUT GRADUALLY WARM
ABOVE NORMAL BY THE WEEKEND. AFTER TONIGHT...NO PRECIPITATION IS
EXPECTED THROUGH FRIDAY.

IN THE EXTENDED...MAIN FOCUS IS THE RIDGE REBUILDING ACROSS THE AREA
AND THE POTENTIAL FOR ANY SHORT-WAVES TO BRING BACK DOOR COOLING.
FOR THE FORECAST...FAVORED A SUPERENSEMBLE CONSISTING OF THE 06Z
GFS...00Z ECMWF AND 00Z CANADIAN. THE 00Z GFS WAS THE ONLY MODEL TO
SHOW STRONG BACKDOOR COOLING LATE SUNDAY AND MONDAY. WHILE SUPPORTED
BY THE 00Z GFS ENSEMBLE...AM CONCERNED THE LACK OF SUPPORT FROM
OTHER OPERATIONAL RUNS MAKES THIS SCENARIO LESS LIKELY.
INSTEAD...BOTH ECMWF AND 06Z GFS HINT AT BACKDOOR COOLING ON TUESDAY
BUT EVEN THIS MAY BE OVERDONE AS THE GFS IS STRONGEST WITH THIS
FRONT. THEREFORE...WITH SUCH STRONG UNCERTAINTY THAT ANY WAVE WILL
APPROACH THE CWA...HAVE KEPT CONDITIONS DRY THROUGH TUESDAY. AS
POSITION OF FRONTS AND SHORT-WAVES ARE IN BETTER FOCUS...MAY NEED TO
ADD A CHANCE OF THUNDERSTORMS EARLY NEXT WEEK.

FOR THE DAY TO DAY...IT LOOKS LIKE INCREASING SOUTHERLY FLOW
BRINGING UP HIGHER DEW POINTS AND WARMER AIR. WITH RIDGE LINGERING
ACROSS ON IOWA ON SATURDAY...KEPT MAXES IN THE LOWER 80S IN NW IOWA
WITH NEAR 90 WEST OF THE JAMES. AS FLOW TURNS TO SOUTH BY
SUNDAY...MINS WILL REMAIN IN THE 60S AND MAXES WILL RANGE FROM THE
MID 80S IN SW MN TO THE LOW 90S ALONG AND WEST OF THE JAMES FOR
SUNDAY AND MONDAY. DID COOL TEMPS A COUPLE OF DEGREES ON TUESDAY
GIVEN POTENTIAL FOR A BACKDOOR FRONT BUT WITH HIGH UNCERTAINLY KEPT
TEMPS ABOVE NORMAL.

&&

.AVIATION...
MAINLY IFR CONDITIONS AT KFSD AND KHON EARLY THIS EVENING...WITH A
GRADUAL RISE TO MVFR AND VFR CONDITIONS BY 12Z. KSUX SHOULD BE MVFR
LATE AFTERNOON AND EARLY EVENING WITH RAIN AND ISOLATED
THUNDERSTORMS. POSSIBLY SOME IFR VISBYS IN FOG LATE AT KSUX.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.

&&

SCHUMACHER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1135 AM CDT TUE AUG 28 2007

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-291200-
AURORA-BEADLE-BON HOMME-BROOKINGS-BRULE-BUENA VISTA IA-
CHARLES MIX-CHEROKEE IA-CLAY-CLAY IA-COTTONWOOD MN-DAKOTA NE-
DAVISON-DICKINSON IA-DIXON NE-DOUGLAS-GREGORY-HANSON-HUTCHINSON-
IDA IA-JACKSON MN-JERAULD-KINGSBURY-LAKE-LINCOLN-LINCOLN MN-
LYON IA-LYON MN-MCCOOK-MINER-MINNEHAHA-MOODY-MURRAY MN-NOBLES MN-
OBRIEN IA-OSCEOLA IA-PIPESTONE MN-PLYMOUTH IA-ROCK MN-SANBORN-
SIOUX IA-TURNER-UNION-WOODBURY IA-YANKTON-
1135 AM CDT TUE AUG 28 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA...
SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS...
A BAND OF SHOWERS AND ISOLATED THUNDERSTORMS WILL DRIFT SOUTHEAST
THROUGHOUT THE DAY...BRINGING LIGHT RAIN WITH SOME ISOLATED
HEAVIER DOWNPOURS TO SOME LOCATIONS. ISOLATED THUNDERSTORMS WILL
ALSO BE POSSIBLE EARLY THIS AFTERNOON OVER NORTHWEST IOWA...WHERE
SOME SMALL HAIL WILL BE POSSIBLE. OVERALL...THE THREAT OF
THUNDERSTORMS IS EXPECTED TO DRIFT SOUTH OF THE AREA BY MIDNIGHT.

FLOODING...
FLOODING DUE TO HEAVY RAINS LAST WEEK WILL CONTINUE ALONG PART OF
THE LITTLE SIOUX RIVER...FROM NEAR MILFORD DOWNSTREAM TO LINN
GROVE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

&&

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.CRH.NOAA.GOV/FSD. THIS INCLUDES THE GRAPHICAL HAZARDOUS
WEATHER OUTLOOK.

08