Melting snow caused the Big Sioux River to rises to above flood stage from east of Alcester to southeast of Big Springs from February 11th through the 14th.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS FSD wrote it up.
Melting snow caused the Big Sioux River to rises to above flood stage from east of Alcester to southeast of Big Springs from February 11th through the 14th.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Sioux Falls, SD wrote its last area forecast discussion before the first event at Feb 10, 9:15 PM CST, 2 hours 45 minutes earlier.
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 915 PM CST TUE FEB 10 2009 .DISCUSSION... MADE SOME MINOR CHANCE TO TEMPS AND SKY COVER FOR TONIGHT. NUISANCE STRATUS WITH LARGE BREAKS MAIN FACTOR IN WIND SPEEDS AND TEMPERATURES. BETTER MIXING UNDER STATUS KEEPING WINDS AND TEMPS UP...WHILE LESS SKY COVER YIELDING LIGHTER WINDS. BUMPED LOWS UP A FEW DEGREES FOR STRATUS AND THICKER CIRRUS APPROACHING FROM THE S...PLUS JUST NOT SEEING MUCH FOR COOLER TO THE N. OF COURSE AREAS WHERE CLEAR SKIES PREVAIL FOR A FEW HOURS COULD EASILY DROP INTO THE MID 20S. NEW GRIDS HAVE BEEN SENT. && .AVIATION... BKN MVFR CIGS FM 2KFT TO 3KFT NW OF A LN FM MWM TO FSD TO ONL AT 03Z...EXPCD TO MOVE SLOWLY SEWD...REACHING A LN FM SPW TO SLB BY 11Z OR SO. INCRG NWLY WINDS WED MRNG WITH FQT WIND GUSTS ARND 25 KTS EXPCD BY 16Z MOST AREAS. && .PREV DISCUSSION... IN THE SHORT TERM TONIGHT...THE FSD FA IS CAUGHT IN BETWEEN SYSTEMS. OUR UPPER LOW TO THE NORTH...CURRENTLY OVR THE MN ARROWHEAD...WL WEAKEN AS IT MOVES INTO SRN ONTARIO. TO THE SOUTH...WE HAVE A STRONG UPPER TROF MOVG ACROSS THE SRN PLAINS. IN BETWEEN IN THIS IMMEDIATE AREA...WEAK MID AND UPPER TROFFING IS NOTED CAUSING LITTLE IN THE WAY OF WEATHER. THEREFORE LEFT CONDITIONS DRY. THERE WL BE A DRAMATIC INCREASE IN THICK MID TO HIGH CLOUDS ACROSS THE SRN PORTIONS OF OUR FA AS THE EVENING PROGRESSES DUE TO THE SRN STREAM SYSTEM. FURTHERMORE...OUR LLV WINDS WL TURN TO THE NW OVERNIGHT WHICH COULD VERY WELL BRING DOWN SOME STRATUS FM THE NORTH. SO ANY WAY YOU SLICE IT...WE ARE PROBABLY LOOKING AT MOSTLY CLOUDY CONDS DEVELOPING THRU A BULK OF THIS FA AFTER EVENING. AS FAR AS TEMPS... OUR GOING MIN TEMPS STILL DO NOT LOOK TOO BAD. AM BANKING ON SOME CLOUD COVER AND A BIT OF WIND TO KEEP THEM FM TOTALLY TANKING. LESS WINDY FOR SURE ON WEDNESDAY...BUT STILL A BREEZY DAY AS CAA CONTINUES TO CYCLE AROUND EXITING SIDE OF THE UPR VORTEX AND WITH STRONG WAVE SLIDING TOWARD OHIO VALLEY. A FAIR AMOUNT OF LOWER CLOUDS LKLY TO EITHER START THE DAY ACRS AREAS FROM THE JAMES VALLEY EWRD...OR AT WORST FORMING WITHIN THE CAA WITH DAYTIME HEATING. POTENTIAL TO KNOCK A FEW MORE DEGREES OFF MAX TMPS FROM EXPECTATIONS WHICH WERE DERIVED TAKING A COUPLE DEGREES OFF MIXING TO ARND 900 HPA...GREATEST ACRS NRN AREAS. GRADUALLY...MIXING AND SUBSIDENCE WL FAVOR A DECREASE IN CLOUDS FROM SW. WITHOUT A GREAT DEAL OF SNOWCOVER IN ANYWHERE BUT NON RURAL AREAS OF THE NORTH THROUGH EAST...WILL NOT TAKE MUCH TO WARM WITH ANY SUNSHINE. DID KEEP A FEW FLURRIES MAINLY N OF A KBKX TO KMWM LINE BY WED AFTN...WITH APPROACH OF SECONDARY TROUGHING IN NW FLOW. IF TEMPS WERE A BIT COOLER IN THE CLOUD LAYER...WOULD FEEL A BIT MORE STRONGLY ON GETTING FLURRIES THRU THE NERN AREAS...BUT LOOKED SAFE TO KEEP MEASURABLE MENTION NORTH OF THE CWA CLOSER TO THE DEEPER MOISTURE/FORCING. COOL SFC RIDGE CONTINUES TO SLOWLY BUILD SWRD FROM WED NIGHT THRU THU NIGHT...WITH NRN PLAINS REMAINING IN THE CONFLUENCE BETWEEN STREAMS...AND JUST UPSTREAM OF THE CONFLUENT JET ENTRANCE. AGEOSTROPHICALLY...THIS FAVORS CONTINUED FEED OF COOLER AIR...AND OVERALL BENIGN CONDITIONS. MORE CLOUDS WITHIN ZONE LKLY TO SPREAD IN FROM THE WEST BY LTR THU AND THU NIGHT. SPLIT FLOW STARTS TO BECOME MORE OF AN ISSUE AS THE NEXT SRN STREAM WAVE EJECTS TOWARD THE PLAINS ON FRIDAY. OPERATIONAL GFS IS THE NORTHERN EXTREME OF THE 12Z ENSEMBLE SET... WITH MOST OF THE MEMBERS WITH APPRECIABLE MORE NORTHERN STREAM ENERGY AND KEEPING CLOSED SYSTEM WELL TO S. ECMWF HAS BEEN THE CONSISTENT NRN VOICE...CANADIAN THE SOUTHERN SIDE. HARD TO FORGET THAT SUCH SRN STREAM WAVES IN SPLIT FLOW HAVE COMMON TENDENCY TO SNEAK MORE TO N THAN EXPECTED. THIS WOULD BE A VERY FRONTAL SYSTEM WITH A SHARP NRN BNDRY DUE TO LEADING DRY AIR AND CONTINUED LOW LVL CAA...WITH MAIN FORCING THIS FAR N DERIVED FRONTALLY IN THE MID LVLS. THEREFORE AT THIS TIME...WL KICK UP GRADIENT IN POPS FRIDAY THRU FAR SRN CWA...PUSHING LOW CHC AS FAR N AS A PONCA NEBRASKA TO SOUTH OF KSPW. PCPN THREAT LINGERS FRI EVENING THRU THE SERN CWA BEFORE PULLING AWAY...AND COLDER AIR AGAIN TAKING CONTROL. IN THE EXTENDED RANGE /SAT THRU TUE/...SPLIT FLOW REMAINS AN ACTIVE CHALLENGE WITH VARIOUS SRN/NRN STREAM WAVES MOVING INTO THE REGION. CONSENSUS OF SEVERAL SLNS WOULD FAVOR SYSTEM SNEAKING BY TO S ON SAT NIGHT...AND A MORE AGGRESSIVE SYSTEM BY MONDAY INTO EARLY TUE. GFS ENSEMBLES ARE TOTALLY OUT OF SYNC BY DAYS 6/7 AND NOT MUCH VALUE. WL KEEP LOW POPS OF A FRONTALLY FORCED LIGHT SNOWFALL THRU MO VLY ON SAT NIGHT AND LIFTING THRU ERN CWA SUNDAY...ALLOWING FOR A BREAK SUN NIGHT WITH WK RIDGING. FOR THE MOMENT...ONLY ENOUGH CONFIDENCE FOR LOW END POPS...BUT SETUP WITH POTENTIAL INVERTED TROUGH WITH PCPN DEVELOPING WITHIN WAA AHEAD WOULD EVENTUALLY FAVOR HIGHER POPS THAN CURRENTLY WILLING TO RISK. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && UPDATE...97/RYRHOLM CHAPMAN/MJF
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</html>The national radar mosaic for the moment the first event began.
1 flood. Local standard time, as filed.
Minor flooding along the Big Sioux River resulted from the melting of snow. Some farmland and a few county roads were partially flooded.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2009Every state in 2009This day in weather historyWarnings in South Dakota, February 2009
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 156183.