Moderate to major flooding of the James River, which began in March due to snowmelt and continued through April, continued further through May. Farmland and a few roads remained flooded, but no significant new flooding occurred.
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.
Moderate to major flooding of the James River, which began in March due to snowmelt and continued through April, continued further through May. Farmland and a few roads remained flooded, but no significant new flooding occurred. The river generally fell during the month, but changes continued to be very slow.
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 Apr 30, 8:30 PM CST, 3 hours 30 minutes earlier.
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 930 PM CDT FRI APR 30 2010 .DISCUSSION... LINGERING LGT SHWRS/SPRINKLES HAVE ALMOST DSIPTED AND FCST LOOKS ON TARGET THERE. WILL UPDATE ZONES IN A LTL BIT TO REMOVE THE SHWR/SPRINKLE MENTN. OTRW FCST HAS BEEN GOING WELL...COOLED LOWS SWRN CRNR OF FCST AREA EVER SO SLIGHTLY. KEPT MOCLDY W...MAINLY NW...TO PTCLDY ELSEWHERE. CURRENT BREEZES SHUD HOLD FAIRLY STDY. AN OCNL MINOR PICKUP IN SPEED PSBL BUT MAIN WIND INCREASE WILL BE AFTER DAYBREAK. && .AVIATION... VFR CONDITIONS ANTICIPATED THROUGH 00Z SUNDAY. MAINLY MID LEVEL CIGS ACROSS THE AREA...THOUGH AREAS 3-4KFT CIGS WILL ROTATE THROUGH NWRN HALF OF THE CWA THROUGH 9-10Z. MIXY WEST-SOUTHWEST WINDS WILL FOR SATURDAY WILL RESULT IN NUMEROUS GUSTS AOA 25KTS DEVELOPING SHORTLY AFTER SUNRISE SATURDAY...WITH GUSTS DROPPING OFF BY 00Z SUNDAY. /JH && .PREV DISCUSSION... BEGINNING TO SEE A FEW SHOWERS AND THUNDERSTORMS DEVELOP OVER PORTIONS OF NORTH CENTRAL AND NORTHEASTERN SOUTH DAKOTA THIS AFTERNOON ALONG AN INSTABILITY AXIS SITUATED OVER THAT AREA...AND MAY SEE SOME OF THIS ACTIVITY SCRAPE ACROSS OUR NORTHERN LOCALES INTO THE VERY EARLY EVENING. WITH COLD AIR ALOFT/FREEZING LEVELS AROUND 6000 FT/WEAK ELEVATED CAPE/MIDLEVEL SHEAR MAY SEE SOME SMALL HAIL WITH THESE STORMS. OTHERWISE...EXPECTING THIS ACTIVITY TO WANE AFTER SUNSET. THE UPPER LEVEL LOW CENTERED OVER WESTERN NORTH DAKOTA LATE THIS AFTERNOON WILL SWING TO THE SOUTH AND EAST OVERNIGHT...KEEPING A GOOD BIT OF CLOUD COVER IN OUR NORTH...BUT THINK THAT ANY PRECIPITATION WILL REMAIN TO THE NORTH OF OUR CWA. EVEN WITH CAA...TEMPERATURES TONIGHT WILL NOT DROP OFF TOO DRASTICALLY...GENERALLY IN THE LOWER 40S...WITH WINDS STAYING UP IN RESPONSE TO A TIGHTENING GRADIENT AS SURFACE LOW PRESSURE WINDS UP ALONG THE U.S./CANADIAN BORDER. /JM BRISK WSWLY FLOW SHOULD MIX OUT VERY WELL FOR SAT...WITH WARMEST TEMPS FOR SERN CWA. WSWLY WINDS SHOULD NOT GET TOO OUT OF CONTROL WITH LITTLE COLD ADVECTION APPARENT. ALSO APPEARS CAP ABV 600MB SHOULD PRECLUDE AFTN CONVECTION FOR MOST OF AREA SO WILL LEAVE DRY. FAIRLY MIXY AND MILD FOR SAT NGT ESP EAST OF I29 WHERE GRADIENT LINGERS. FOR SUN SHOULD BE COLD ADVECTION ALOFT ASSCD WITH NRN STREAM SHORT WAVE. PUT IN ISOLD -SHRA ENTIRE AREA IN THE AFTN... WITH MORE FOCUS TO THE SOUTH...BUT COLDER AIR ALOFT TO THE NORTH. COOLER SFC RIDGE MOVES ESE OVER CWA SUN NGT AND MAY BE SOME GOOD RADIATIONAL COOLING. THEN WLY FLOW GRADUALLY BECOMES SLY FM MON THRU EARLY TUE WITH MODIFYING AIR MASS. BEST WARMING FOR MON AFTN SHOULD BE ALONG MISSOURI VALLEY WITH WARM ADVECTION...AND FOR TUES WILL BE SRN AND ERN CWA WITH BEST MIXING ALG AND AHEAD OF CDFNT. 18Z NAM APPEARS TO HAVE A SLOW AND COLD BIAS DURG THIS PERIOD. PUT IN A SLGT CHC TSTMS EAST OF I29 TUES AFTN WITH FOCUS AHEAD OF NRN STREAM SHORT WAVE...BUT ANOTHER WEAK BAROCLINIC ZONE AFFECTS SRN CWA TUES NGT BEHIND CDFNT. MODELS HAVE TYPICAL CONTINUITY ISSUES WITH SHORT WAVES IN THE LONG RANGE...BUT IT APPEARS FROM COMPOSITE OF MODELS THAT THERE IS A CHC OF RAIN MAINLY ALONG AND SOUTH OF I90 FOR THU NGT INTO FRI MRNG. NO SNOWSTORM LIKE THE 00Z ECMWF HAD...BUT IT SHOULD BE COOLER THAN 12Z HPC GUID HIGHS FOR WED THRU FRI./ RYRHOLM && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. WILLIAMS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SIOUX FALLS SD 1130 AM CDT FRI APR 30 2010 SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098- IAZ001>003-012>014-020>022-031-032-NEZ013-014-011200- 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- 1130 AM CDT FRI APR 30 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA... SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS... SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE AREA THIS AFTERNOON. SOME OF THE STRONGER STORMS MAY BE CAPABLE OF PRODUCING HAIL TO THE SIZE OF NICKELS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SOUTHWEST TO WESTERLY WINDS OF 20 TO 35 MPH ARE EXPECTED TO DEVELOP ACROSS THE AREA ON SATURDAY. THESE WINDS WILL SUBSIDE SATURDAY NIGHT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT. && FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT WWW.WEATHER.GOV/SIOUXFALLS. THIS INCLUDES THE GRAPHICAL HAZARDOUS WEATHER OUTLOOK.
The national radar mosaic for the moment the first event began.
6 flood. Local standard time, as filed.
Flooding of the James River continued from March and April through all of May. The river fell very slowly, with some farmland and roads remaining flooded.
Flooding of the James River continued from March and April through all of May. The river fell very slowly, with some farmland and roads remaining flooded.
Flooding of the James River continued from March and April through all of May. The river fell very slowly, with some farmland and roads remaining flooded.
Flooding of the James River continued from March and April through all of May. The river fell very slowly, with some farmland and roads remaining flooded.
Flooding of the James River continued from March and April through all of May. The river fell very slowly, with some farmland and roads remaining flooded.
Flooding of the James River continued from March and April through all of May. The river fell very slowly, with some farmland and roads remaining flooded.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2010Every state in 2010This day in weather historyWarnings in South Dakota, May 2010
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: 236720, 236721, 236722, 236724, 236726, 236727.