A rapid warm up developed in early March after significant snowfall at the end of February and the beginning of March. The warm up resulted in a rapid snowmelt which was enough to cause minor to moderate flooding on the Big Sioux, Little Sioux, and Floyd Rivers.
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.
A rapid warm up developed in early March after significant snowfall at the end of February and the beginning of March. The warm up resulted in a rapid snowmelt which was enough to cause minor to moderate flooding on the Big Sioux, Little Sioux, and Floyd Rivers. There was a small area of major flooding on the lower Big Sioux River. Lowlands along the rivers were flooded, but no significant damage to farmland, homes, or other property was reported. No significant rain fell during the flooding period, and the flooding subsided during the middle part of March.
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 Mar 11, 2:40 PM CST, 4 hours 20 minutes earlier.
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 340 PM CDT SUN MAR 11 2007 .DISCUSSION... ANOTHER WARM DAY WILL LEAD INTO A MILD NIGHT WITH LOW TEMPERATURES 10 TO 15 ABOVE NORMAL. AS ADVERTISED...TOMORROW WILL CERTAINLY BE THE WARMEST DAY OF THE WEEK...AS TEMPERATURES IN SNOW FREE AREAS WILL RUN 20 TO 30 DEGREES ABOVE NORMAL...WHICH WILL BE CLOSE TO RECORD VALUES IN SOME PLACES. AREAS WITH DEEP SNOW COVER INTO SW MN AND NW IA WILL LIKELY NOT MAKE IT PAST THE MID 50S ASSUMING ISOTHERMAL TEMPERATURES FROM 950 MB. WILL LIKELY BE SOME CIRRUS AROUND...BUT HAVE A FEELING THE THICKNESS AND AMOUNT OF CIRRUS IS OVERDONE BY THE GFS SO WENT CLOSE TO FULL MIXING IN SNOW FREE AREAS. WITH THE UNSEASONABLE WARM TEMPERATURES WILL BE AN INCREASED FIRE DANGER THREAT...MAINLY INTO THE SW CWA WHERE TEMPERATURES WILL REACH INTO THE MID 70S AND BREEZY CONDITIONS. FROPA STILL SCHEDULED FOR MON NIGHT...MODELS DISAGREE WITH THE DEGREE OF COOLING...WITH THE NAM MUCH COLDER THAN THE GFS...WHICH WOULD MEAN COOLER TEMPERATURES THAN GOING FORECAST INDICATES. EITHER WAY...A WELL MIXED ATMOSPHERE SHOULD KEEP TEMPERATURES MONDAY NIGHT ABOVE GUIDANCE VALUES. LEFT POPS IN THE NORTH TUE NIGHT INTO WED MORNING AS GFS HAS BEEN CONSISTENT WITH PASSAGE OF SW. ANY PRECIPITATION SHOULD BE ALL RAIN BASED ON GFS TEMPERATURES ALOFT. STRONG UPPER LEVEL WAVE DIGS THROUGH THE UPPER MIDWEST INTO THE GREAT LAKES LATE IN THE WEEK. THIS BREAKS DOWN ZONAL FLOW PATTERN AND ALLOWS FOR MORE AMPLIFIED PATTERN IN THE UPPER LEVELS...WITH NORTHWEST FLOW DOMINATING OVER OUR REGION. GFS QUITE A BIT STRONGER WITH THE TROUGH DIGGING OVER THE EASTERN CONUS THAN OTHER GLOBAL MODELS...ESPECIALLY THE 11/12Z GFS RUN. MAIN EFFECT OF THIS APPEARS TO BE THAT 12Z GFS IS MORE AGGRESSIVE WITH THE COOLING AFTER THE WAVE PASSES THURSDAY/FRIDAY THAN 00Z GFS/ECMWF/CANADIAN SHOW. WITH 12Z RUN BEING AN OUTLIER REGARDING STRENGTH OF THIS TROUGH...WILL KEEP TEMPS NEAR/JUST ABOVE WARMER 00Z GFS GUIDANCE. AS FOR PRECIP CHANCES...WILL MAINTAIN SLIGHT CHANCE IN THE NORTHEAST CWA THURSDAY AS THE WAVE PASSES TO OUR NORTHEAST. WILL KEEP FORECAST DRY BEYOND THAT...WITH MODELS ONLY SHOWING VERY WEAK RIPPLES MOVING QUICKLY THROUGH THE NORTHWEST FLOW ALOFT...AND HIGH PRESSURE THE DOMINANT SURFACE FEATURE OVER THE NORTHERN PLAINS. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && LIEBL/JH
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SIOUX FALLS SD 0524 AM CDT SUN MAR 11 2007 SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098- IAZ001>003-012>014-020>022-031-032-NEZ013-014-121200- 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- 0524 AM CDT SUN MAR 11 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA... SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA. .DAY ONE...TODAY AND TONIGHT FLOODING... MILD TEMPERATURES ARE RAPIDLY MELTING THE SNOW PACK ACROSS THE AREA. RUNOFF FROM THIS MELTING SNOW IS CURRENTLY PRODUCING MINOR TO MODERATE LOW LAND FLOODING ALONG PORTIONS OF THE LOWER JAMES AND LOWER VERMILLION RIVERS. MANY OTHER STREAMS AND RIVERS ACROSS SOUTHEAST SOUTH DAKOTA WILL CONTINUE TO RISE OVER THE NEXT COUPLE OF DAYS...AS SNOW CONTINUES TO MELT QUICKLY. GENERALLY...ONLY MINOR TO MODERATE LOW LAND FLOODING IS EXPECTED. INCREASED RIVER FLOWS CAN ALSO BE EXPECTED INTO SOUTHWEST MINNESOTA AND NORTHWEST IOWA BY EARLY THIS WEEK...WITH RAPID SNOW MELT AND DAYTIME TEMPERATURES MUCH ABOVE NORMAL. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY WITH THE SNOW COVER GONE FOR THE PAST SEVERAL DAYS...THE GRASSLAND FIRE DANGER INDEX IS REACHING THE EXTREME CATEGORY IN GREGORY COUNTY...AND VERY HIGH IN BRULE AND CHARLES MIX COUNTIES FOR MONDAY. MUCH ABOVE NORMAL TEMPERATURES ARE EXPECTED...WITH MONDAY AFTERNOON HIGHS RANGING FROM ABOUT 70 TO 75. RELATIVE HUMIDITY VALUES WILL FALL TO 20 TO 30 PERCENT...AND SOUTHWEST WINDS WILL AVERAGE 15 TO 20 MPH. .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.
The national radar mosaic for the moment the first event began.
8 flood. Local standard time, as filed.
Warm temperatures caused a rapid snowmelt which caused the Little Sioux River to rise above flood stage for several days. The flooding vwas light to moderate, and no significant damage was reported. The river crested at 3.8 feet above flood stage at Milford on March 15th.|
Warm temperatures caused a rapid snowmelt which caused the Big Sioux River to rise above flood stage for several days. The flooding varied from minor to major with lowlands near the river flooded. The amount of damage was not known but was not suspected to be large. The river crested at 7.7 feet above flood stage at Hawarden on March 16th. The snowmelt also caused the Rock River to flood. It crested at 1.5 feet above flood stage at Rock Valley on March 15th. The snowmelt also caused the Floyd River to flood. It crested at 5 feet above flood stage at Alton on March 13th.|
Warm temperatures caused a rapid snowmelt which caused the Little Sioux River to rise above flood stage for several days. The flooding vwas light to moderate, and no significant damage was reported. The river crested at 6 feet above flood stage at Spencer on March 15th.|
Warm temperatures caused a rapid snowmelt which caused the Little Sioux River to rise above flood stage for several days. The flooding vwas light to moderate, and no significant damage was reported. The river crested at 3.5 feet above flood stage on March 21st.
Warm temperatures caused a rapid snowmelt which caused the Little Sioux River to rise above flood stage for several days. The flooding vwas light to moderate, and no significant damage was reported. The river crested at 3.3 feet above flood stage at Linn Grove on March 16th.|
Warm temperatures caused a rapid snowmelt which caused the Little Sioux River to rise above flood stage for several days, where the river crosses the extreme southeast corner of the county. The flooding vwas light to moderate, and no significant damage was reported.
Warm temperatures caused a rapid snowmelt which caused the Big Sioux River to rise above flood stage for several days. The flooding was minor to moderate with no significant damage reported. The snowmelt also caused the Rock River to flood. It crested at 6.3 feet above flood stage at Rock Rapids on March 15th.|
Warm temperatures caused a rapid snowmelt which caused the Big Sioux River to rise above flood stage for several days. The flooding varied from minor to major with lowlands near the river flooded. The amount of damage was not known but was not suspected to be large. The river crested at 5.8 feet above flood stage at Akron in the late evening of March 16th. The snowmelt also caused the Floyd River to flood. It crested at less than half a foor above flood stage on March 14th, but the flooding was a little more upstream where the Floyd River crossed the northern edge of the county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2007Every state in 2007This day in weather historyWarnings in Iowa, March 2007
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 2026-09-24. Each event’s entry at NCEI: 23505, 23494, 23506, 23509, 23507, 23508, 23490, 23497.