In the early morning hours of the 6th, a warm front was located over eastern South Dakota. By sunrise, the warm front had surged north and was located over south central Nouth Dakota.
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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 FGF wrote it up.
In the early morning hours of the 6th, a warm front was located over eastern South Dakota. By sunrise, the warm front had surged north and was located over south central Nouth Dakota. A strong surge of moisture and wind occurred just above the surface layer (and along the warm front), fueling a long line of thunderstorms from eastern North Dakota all the way south into northern Texas. Showers and thunderstorms moved into the Ransom and Sargent county areas on the evening of the 5th and continued over the area until around sunrise on the 6th. Rain had also occurred over these two counties the night of the 5th, giving a 2 day total of 4 to 6 inches of rain.
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 Grand Forks, ND wrote its last area forecast discussion before the first event at May 6, 3:30 AM CST, 2 hours 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 430 AM CDT SUN MAY 6 2007 .SHORT TERM... HIGH AMPLITUDE FLOW WILL TRANSITION TO A SPLIT FLOW OVER NORTH AMERICA WITH NORTHERN STREAM ACROSS SOUTHERN CANADA AND SOUTHERN STREAM AROUND DESERT SOUTHWEST LOW. UPPER LEVEL LOW OVER OVER THE ROCKIES FORECAST TO LIFT INTO SOUTHWEST MB THIS AFTERNOON AND HUDSON BAY BY MON AFTERNOON. MAIN UPPER LOW WILL REMAIN OVER THE DESERT SOUTHWEST. WATER VAPOR LOOP INDICATED SHORT WAVES OVER WESTERN ND AND WESTER SD MOVING NORTH. 700 HPA THETA-E BULLSEYE CENTERED NEAR GFK MOVES INTO SOUTHERN MB BY 12Z. THEREAFTER 700 THETA-E RIDGE BECOMES ESTABLISHED OVER THE MN SIDE OF THE RED RIVER. LOW LEVEL CIRCULATION OVER SOUTHWEST ND MOVES INTO SOUTHWEST MB THIS AFTERNOON WITH A TROUGH EXTENDING INTO WESTERN NEB. CIRCULATION OPENS UP TONIGHT AND BECOMES AN OPEN WAVE AND SHIFTS THETA E RIDGE TO THE EAST BY MID DAY MON. MESOSCALE ANALYSIS SHOWS BEST SURFACE WARM ADVECTION OVER NORTHEASTERN SD. SURFACE MIXING RATIO AXIS EXTENDS FROM WESTERN IA/EASTERN NEB INTO WESTERN ND. SURFACE RIDGE OVER ONT CONTINUES TO DRIVE DRY DRIER AIR INTO MN ARROWHEAD AND WI. .LONG TERM... NO CHANGES. && AVIATION... CIGS LOWER FROM EAST TO WEST ACROSS THE FORECAST AREA. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...FLASH FLOOD WARNING THROUGH SUNDAY MORNING FOR NDZ049-052. MN...NONE. && HOPPES
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND FORKS ND 236 PM CDT SAT MAY 5 2007 MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024- 026>030-038-039-049-052>054-061945- WEST POLK-NORMAN-CLAY-KITTSON-ROSEAU-LAKE OF THE WOODS- WEST MARSHALL-EAST MARSHALL-NORTH BELTRAMI-PENNINGTON-RED LAKE- EAST POLK-NORTH CLEARWATER-SOUTH BELTRAMI-MAHNOMEN- SOUTH CLEARWATER-HUBBARD-WEST BECKER-EAST BECKER-WILKIN- WEST OTTER TAIL-EAST OTTER TAIL-WADENA-GRANT-TOWNER-CAVALIER- PEMBINA-BENSON-RAMSEY-EASTERN WALSH COUNTY-EDDY-NELSON- GRAND FORKS-GRIGGS-STEELE-TRAILL-BARNES-CASS-RANSOM-SARGENT- RICHLAND-WESTERN WALSH COUNTY- 236 PM CDT SAT MAY 5 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN NORTH DAKOTA...WEST CENTRAL AND NORTHWEST MINNESOTA. .DAY ONE...TONIGHT SIGNIFICANT RAINFALL IS POSSIBLE TONIGHT AND SUNDAY IN THE SOUTHERN RED RIVER VALLEY BASIN. THIS ADDITIONAL RAINFALL MAY CAUSE FLOODING IN THIS AREA. THERE IS ALSO A CHANCE FOR AN ISOLATED SEVERE THUNDERSTORM CONTAINING LARGE HAIL IN SOUTHEAST NORTH DAKOTA. STRONG WINDS ARE ALSO .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH SATURDAY THUNDERSTORM ARE POSSIBLE ON SUNDAY...AND ADDITIONAL HEAVY RAIN FALL WILL INCREASE THE THREAT FOR FLOODING IN THE SOUTHERN RED RIVER VALLEY. THE SLOW MOVING WEATHER SYSTEM WILL MOVE AWAY FROM THE REGION ON MONDAY...AND PROVIDE IMPROVING WEATHER CONDITIONS BY TUESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED FOR HEAVY RAIN REPORTS AND ISOLATED SEVERE WEATHER TONIGHT AND SUNDAY. DK
The Aberdeen radar (KABR), 115 km away, was scanning. The volume nearest the first event began at 11:50 UTC.
2 flash flood. Local standard time, as filed.
Many roads in Elliott township and along the Dead Colt Creek south of Lisbon were flooded by the heavy rain.
Many township roads were flooded along the Wild Rice River between Brampton and Rutland.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Dakota in 2007Every state in 2007This day in weather historyWarnings in North Dakota, May 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: 35532, 35533.