A line of thunderstorms formed across west central Minnesota, clipping the southern portions of Grant County. Large hail was reported in Hoffman.
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 FGF wrote it up.
A line of thunderstorms formed across west central Minnesota, clipping the southern portions of Grant County. Large hail was reported in Hoffman. Many other areas reported the ground white with pea sized hail.
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 5, 8:19 PM CST, 55 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 919 PM CDT SAT MAY 5 2012 .DISCUSSION... FORECAST CHALLENGE OVERNIGHT WILL BE HEAVY RAIN POTENTIAL IN THE SOUTHERN FORECAST AREA. WIDESPREAD THUNDERSTORM ACTIVITY ACROSS EASTERN SOUTH DAKOTA WILL MOVE NORTHEASTWARD AND SHOULD IMPACT EXTREME SOUTHEASTERN NORTH DAKOTA AND WEST CENTRAL MINNESOTA LATER TONIGHT. PRECIPITABLE WATER VALUES IN THE SOUTHERN AREAS OVERNIGHT SHOULD BE 140-150 PERCENT OF NORMAL FOR EARLY MAY. FORECAST SOUNDING INDICATE A DEEP SATURATED LAYER BY 06Z UP TO AROUND 750 MB. K INDEX VALUES ACROSS THE SOUTHERN AREAS SHOULD CLIMB INTO THE 30-35 RANGE LATE TONIGHT. WATER VAPOR IMAGERY WAS SHOWING A NORTHEASTWARD EXTENSION OF MID LEVEL MOISTURE IN THE SOUTHWESTERLY FLOW ALOFT. VERY SHALLOW DRY LAYER WITH EASTERLY FLOW SHOULD QUICKLY BE OVERWHELMED BY THE CONVECTION. AN AREA OF STRONG 850 MILLIBAR WARM ADVECTION SHOULD CONTINUE TO ENHANCE LOW LEVEL LIFT AND MAINTAIN THUNDERSTORM ACTIVITY THROUGHOUT THE NIGHT. THUS...1 TO 2 INCH AMOUNTS OF RAIN...WITH LOCALLY 3 INCHES ARE POSSIBLE IN AREAS WITH HIGH RAINFALL RATES. TRAINING THUNDERSTORMS ARE POSSIBLE IN WEST CENTRAL MINNESOTA PER NESDIS SPENES MESSAGE. RAINFALL WILL DECREASE AND SHIFT INTO EASTERN MINNESOTA TOWARD SUNRISE WITH THE APPROACHING COLD FRONT FROM CENTRAL NORTH DAKOTA. && .AVIATION... EXPECT CEILINGS TO DROP INTO IFR CATEGORY WITH SHOWER AND THUNDERSTORM ACTIVITY OVERNIGHT. CONDITIONS WILL IMPROVE FROM WEST TO EAST DURING THE DAY ON SUNDAY. SURFACE WINDS WILL SWITCH FROM EAST SOUTHEAST TO WESTERLY DURING THE DAY ON SUNDAY. KDVL MAY GUSTY CONDITIONS IN THE EARLY TO MID AFTERNOON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...FLASH FLOOD WATCH UNTIL 7 AM CDT SUNDAY FOR NDZ053. MN...FLASH FLOOD WATCH UNTIL 7 AM CDT SUNDAY FOR MNZ029>031-040. && BRAMER
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 536 AM CDT SAT MAY 5 2012 MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024- 026>030-038-039-049-052>054-061045- 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-EDDY-NELSON-GRAND FORKS- GRIGGS-STEELE-TRAILL-BARNES-CASS-RANSOM-SARGENT-RICHLAND- WESTERN WALSH- 536 AM CDT SAT MAY 5 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN NORTH DAKOTA...WEST CENTRAL AND NORTHWEST MINNESOTA. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED TODAY. SHOWERS WILL SPREAD OVER THE AREA TONIGHT WITH ISOLATED THUNDERSTORMS POSSIBLE IN THE SOUTHEAST NORTH DAKOTA AND WEST CENTRAL MINNESOTA. NO SEVERE WEATHER IS EXPECTED. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED. DTR
The Minneapolis radar (KMPX), 205 km away, was scanning. The volume nearest the first event began at 03:15 UTC.
1 hail. Local standard time, as filed.
The storm left banks of mainly dime to nickel sized hail covering the ground, although there were also some quarter sized hail in the mix. Heavy rain and moderate to strong winds accompanied the hail.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2012Every state in 2012This day in weather historyWarnings in Minnesota, May 2012
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: 369679.