For the second straight night, elevated thunderstorms tracked across portions of southeast North Dakota and west central Minnesota. Early in the morning of the 10th, one supercell tracked from western Sargent and Ransom County, North Dakota, northeast to Fargo/Moorhead, and on to the east-northeast toward Bemidji, Minnesota.
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.
For the second straight night, elevated thunderstorms tracked across portions of southeast North Dakota and west central Minnesota. Early in the morning of the 10th, one supercell tracked from western Sargent and Ransom County, North Dakota, northeast to Fargo/Moorhead, and on to the east-northeast toward Bemidji, Minnesota. The storm produced large hail along its entire path.
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 9, 7:55 PM CST, 3 hours 35 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 855 PM CDT MON MAY 9 2011 .DISCUSSION... FORECAST CHALLENGE TONIGHT WILL BE PRECIPITATION CHANCES AND OVERNIGHT LOWS. GENERALLY QUIET WEATHER IS EXPECTED FOR THE REMAINDER OF THE EVENING HOURS. THE BEST CHANCE OF LATE NIGHT...AFTER 06Z...SHOWER AND THUNDERSTORM ACTIVITY SHOULD REMAIN IN WESTERN PORTIONS OF THE FORECAST AREA. SATELLITE AND REGIONAL RADAR TRENDS CURRENTLY SHOW ACTIVITY IN WESTERN SD BEGINNING TO EXPAND TO THE NORTH AND EAST. CURRENTLY...LIGHT SHOWER ACTIVITY PERSISTS IN THE NORTHERN DEVILS LAKE BASIN THIS EVENING. HOWEVER...00Z KBIS SOUNDING SHOWS A CAPPING INVERSION STILL IN PLACE AROUND THE 850 MILLIBAR LEVEL. DYNAMICS OF DEVELOPING NOCTURNAL LOW LEVEL EASTERLY JET WILL NEED TO OVERCOME THIS FIRST BEFORE MORE ENERGETIC SD THUNDERSTORM ACTIVITY SLOWLY SPREADS FARTHER NORTHEAST LATER TONIGHT. OTHERWISE...EXTENSIVE CLOUD COVER SHOULD REMAIN IN PLACE FOR THE REMAINDER OF THE NIGHT. OVERNIGHT LOWS SHOULD BE SIMILAR TO LAST NIGHT. THUS...CURRENT TEMPERATURE GRIDS APPEAR TO BE REASONABLE. NO OTHER SIGNIFICANT CHANGES TO THE PACKAGE. && .AVIATION... WIDESPREAD MVFR CEILINGS ARE EXPECTED TO REMAIN ACROSS THE FORECAST AREA OVERNIGHT. SHOWER AND THUNDERSTORM ACTIVITY ARE STILL POSSIBLE LATER TONIGHT AS CELLS CURRENTLY IN THE WESTERN DAKOTAS ATTEMPT TO MOVE NORTH-NORTHEAST OVERNIGHT. THE AIRPORTS MOST LIKELY TO SEE PRECIPITATION AFTER 06Z ARE ONCE AGAIN GENERALLY ALONG AND SOUTHWEST OF A KDVL-KFAR-KFFM LINE. EASTERLY SURFACE WINDS ARE EXPECTED TO INCREASE ON TUESDAY AS THE LOW PRESSURE CENTER MOVES NORTHWARD. THERE IS A CHANCE OF THUNDERSTORM ACTIVITY...SOME POSSIBLY SEVERE...TUESDAY AFTERNOON. HOWEVER...THIS WILL BE DEPENDENT ON A PROLONGED PERIOD OF SUNSHINE TUESDAY WHICH WOULD ENHANCE LOW LEVEL INSTABILITY ACROSS THE FORECAST AREA. && .HYDROLOGY... MODERATE TO MINOR FLOODING CONTINUES IN THE BASIN OF THE RED RIVER OF THE NORTH...WITH THE EXCEPTION OF WEST FARGO WHICH IS STILL IN MAJOR CATEGORY. THE RIVER LEVEL AT ABERCROMBIE IS THE NEXT ONE TO FALL BELOW MINOR FLOOD STAGE OVERNIGHT. IF THE PRECIPITATION FROM LAST NIGHT DOES NOT REVERSE THE SLOW FALLING TREND TONIGHT...THE MINOR FLOOD STAGE WILL BE DROPPED FOR THIS POINT TUESDAY MORNING. OTHERWISE MOST AREA RIVERS ARE RESPONDING ABOUT AS FORECAST. THE CURRENT FORECASTS CONTAIN 24 HOURS OF FORECAST PRECIPITATION...SO ADDITIONAL RAINFALL WILL HAVE TO BE FACTORED INTO LATER FORECASTS. THE MOST LIKELY SCENARIO IS A SLOWING IN THE RATE OF FALL OR MINOR RISES...ALL DEPENDENT ON WHERE THE HEAVIEST RAINS OCCUR. STAY TUNED TO LATER RIVER PREDICTIONS. AREAL FLOOD WARNINGS CONTINUE ALONG THE MAINSTEM RED NORTH OF OSLO TO CANADA...IN CASS COUNTY FROM KINDRED TO HARWOOD...IN PEMBINA COUNTY DOWNSTREAM OF WALHALLA THROUGH NECHE INTO PEMBINA. A FLOOD ADVISORY HAS REPLACED THE AREAL FLOOD WARNING IN THE DEVILS LAKE BASIN AS OVERLAND RUNOFF HAS SUBSIDED. SEE SPECIFIC FLOOD STATEMENTS FOR MORE DETAILS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && BRAMER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND FORKS ND 450 AM CDT MON MAY 9 2011 MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024- 026>030-038-039-049-052>054-101200- 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- 450 AM CDT MON MAY 9 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN NORTH DAKOTA...WEST CENTRAL AND NORTHWEST MINNESOTA. .DAY ONE...TODAY AND TONIGHT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR. THERE IS A SLIGHT CHANCE FOR SEVERE THUNDERSTORMS ACROSS A PORTION OF SOUTHEAST NORTH DAKOTA...MAINLY DURING THE EVENING HOURS. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN THREAT. WIDESPREAD SPRING SNOW MELT AREAL AND RIVERINE FLOODING CONTINUES ALONG THE RED RIVER AND ITS TRIBUTARIES. REFER TO THE LATEST FLOOD WARNINGS AND STATEMENTS FOR DETAILED INFORMATION ON SPECIFIC LOCATIONS. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE TUESDAY INTO TUESDAY NIGHT. THERE IS A SLIGHT CHANCE FOR SEVERE THUNDERSTORMS ACROSS MUCH OF THE REGION FOR TUESDAY AFTERNOON INTO THE EVENING HOURS. THE SITUATION IS STILL UNCERTAIN...BUT LARGE HAIL...DAMAGING WINDS...LOCALLY HEAVY RAINFALL...AND A TORNADO OR TWO WOULD BE POSSIBLE. WIDESPREAD SPRING SNOW MELT AREAL AND RIVERINE FLOODING CONTINUES ALONG THE RED RIVER AND ITS TRIBUTARIES. REFER TO THE LATEST FLOOD WARNINGS AND STATEMENTS FOR DETAILED INFORMATION ON SPECIFIC LOCATIONS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED ON TUESDAY. TG
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
738 PM CDT MON MAY 09 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0220 AM HAIL 2 NW NORCROSS 45.89N 96.23W
05/09/2011 E1.00 INCH GRANT MN PUBLIC
DRIFTS OF HAIL SEVERAL INCHES DEEP IN YARD.
&&
BRAMERThe Aberdeen radar (KABR), 82 km away, was scanning. The volume nearest the first event began at 05:29 UTC.
3 hail, 1 thunderstorm wind. Local standard time, as filed.
A basketball hoop set was blown down along with several large tree branches. A trampoline was blown onto a tractor nearly a hundred feet away.
Pea to penny sized hail fell.
Pea to quarter sized hail fell off and on for about 10 minutes.
The large hail broke windows on a car.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Dakota in 2011Every state in 2011This day in weather historyWarnings in North Dakota, May 2011
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: 317467, 317468, 317469, 290127.