By the afternoon of the 28th, a weak surface low was located over northeast North Dakota with a warm front extending out to the east. Temperatures rose into the mid to upper 70s with dew points in the low 60s.
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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.
By the afternoon of the 28th, a weak surface low was located over northeast North Dakota with a warm front extending out to the east. Temperatures rose into the mid to upper 70s with dew points in the low 60s. Showers and thunderstorms flared up along the Red River Valley into northwest Minnesota, producing large hail and strong wind gusts.
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 28, 8:41 AM CST, 1 hour 19 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 941 AM CDT THU MAY 28 2015 .UPDATE... ISSUED AT 936 AM CDT THU MAY 28 2015 SHOWERS AND ISOLATED THUNDER CONTINUE TO LIFT NE WITH MAIN BAND OVER NE FORECAST AREA. FARTHER SW CELLS MORE ISOLATED. AS WAVE LIFTS INTO CANADA WILL SEE A BREAK BEHIND THE RAIN UNTIL PROBABLY LATER THIS AFTERNOON. ADJUSTED POPS ACCORDINGLY REMAINDER OF THE MORNING AND WILL ADJUST AT FURTHER UPDATES. NO OTHER CHANGES. UPDATE ISSUED AT 701 AM CDT THU MAY 28 2015 FCST ON TRACK WITH AREA OF SHOWERS MOVING THRU THE RRV INTO MINNESOTA. ISOLD TSTM IN FARGO AREA SO ADDED ISOLD T TO GRID IN SRN RRV FOR NEXT COUPLE HOURS. OVERALL 06Z NCEP MODELS AND HRRR/RAP INDICATE ABOUT THE SAME SCENARIO AS EXPECTED WITH THIS BATCH OF PRECIP EXITING AND THEN SOME REDEVELOPMENT AHEAD OF COLD FRONT MID AFTN. EXACTLY WHERE IS IN QUESTION. HRRR HAS BEEN A BIT FARTHER SOUTH THAN SOME OTHER MODELS WITH MORE FARGO VS GRAND FORKS. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 336 AM CDT THU MAY 28 2015 WATER VAPOR SHOWS SHORT WAVE IN CNTRL ND EARLY THIS MORNING WITH A WEAK SFC LOW IN WCNTRL ND. UPPER WAVE AND SFC LOW WILL MOVE NORTHEAST TODAY. SFC LOW WILL STRENGTHEN SOME AS IT MOVES INTO SOUTHEASTERN MANITOBA THIS AFTERNOON. A COLD FRONT SOUTHWEST FROM THE SFC LOW WILL BE NR A HALLOCK MN-MICHIGAN ND-JAMESTOWN LINE NR 21Z. SOME HEATING WILL OCCUR AHD OF THIS FRONT TODAY WITH HIGHS UP NEAR 80. GFS HAS A BIT MORE BULK SHEAR THAN NAM...AND WITH DEW PTS PROGGED BY GFS IN THE LOW 60S MUCAPE IN THE 2000-2200 J/KG RANGE IS POSSIBLE 21Z-00Z PERIOD IN A CORRIDOR ABOUT 50 MILES AHEAD OF FRONT. MORNING SHOWERS WILL GRADUALLY LIFT NORTHEAST EARLY THIS MORNING. THEN REDEVELOPMENT OF T-STORMS IN THE UNSTABLE CORRIDOR FROM FAR NW MN INTO ECNTRL ND. THE STORMS WILL THEN MOVE SOUTHEAST. IF WE INDEED GET SFC HEATING TO NR 80 AND DEW PTS 60-62...THEN I AGREE WITH SPC IN THAT ISOLD SVR STORMS ARE POSSIBLE. NSSL WRF/SPC WRF ARE ALL A TAD SLOWER THAN HRRR/RAP. T-STORM THREAT WILL LAST A BIT LONGER THAN EARLIER THOUGHT AND ONL SLOWLY EXIT FAR SE ND/WCNTRL MN TONIGHT. CLEARING AND COOLER AIR TO WORK INTO DVL BASIN BY 12Z FRI. FRIDAY WILL BE BREEZY AND MUCH COOLER AS HIGH PRESSURE BUILDS SOUTH. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 355 AM CDT THU MAY 28 2015 FOR FRIDAY NIGHT LIGHTEST WINDS IN NORTH CENTRAL ND-DVL BASIN. STILL IDEA PRESENT OF SOME SCT FROST DVL BASIN-LANGDON-COOPERSTOWN AREA NEAR DAWN SATURDAY WITH LOWS 32-34 DEGREES. SATURDAY WILL SEE SUNSHINE BUT STILL COOL WITH HIGHS AROUND 60. INCREASING HIGH CLOUDS SAT AFTN-NIGHT AHD OF NEXT SHORT WAVE. FOR SUNDAY THROUGH WEDNESDAY... HIGH AMPLITUDE LONG WAVE RIDGE TROUGH WAS LOCATED OVER NORTHERN NORTH AMERICA. LONG WAVE PATTERN DE-AMPLIFIES A BIT OVER NORTHERN CANADA THROUGH THE PERIOD. A MORE ZONAL FLOW IS ACROSS THE STATES THROUGH THE PERIOD. THE ECMWF AND GFS WERE IN GOOD AGREEMENT AT 84 HOURS. HOWEVER THE GFS BECOMES FASTER SOLUTION THAN THE ECMWF BY THE END OF THE PERIOD. BOTH THE GFS AND THE ECMWF WERE SLOWER AND FARTHER NORTH OVER THE LAST COUPLE RUNS. WILL PREFER THE ECMWF. LITTLE CHANGE TO HIGH TEMPS ON SUN. TEMPS INCREASED A DEGREE OR TWO FOR MON AND DECREASED ONE TO THREE DEGREES FOR TUE AND WED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 701 AM CDT THU MAY 28 2015 ISOLD THUNDERSTORM NEAR FARGO WILL EXIT BY 13Z. OTHERWISE EXITING THE NRN VALLEY AND NW MN THIS MORNING. A BREAK EXPECTED...WITH VFR CIGS (HIGH BASED CU AND AC). THEN QUESTION IS TSTM DEVELOPMENT AHEAD OF FRONT AND LOCATION. KEPT VCTS IDEA IN MOST TAFS MID TO LATE AFTN. AFTER EARLY THIS MORNING WINDS WILL BE SOUTHEAST 10 TO 25 KTS THEN TURNING WEST AND NORTH-NORTHWEST BEHIND THE FRONT TONIGHT. SOME RISK OF BRIEF MVFR CIGS BEHIND FRONT BUT KEPT IN VFR CAT FOR NOW. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && UPDATE...VOELKER SHORT TERM...RIDDLE LONG TERM...HOPPES/RIDDLE AVIATION...RIDDLE
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND FORKS ND 725 AM CDT THU MAY 28 2015 MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024- 026>030-038-039-049-052>054-291230- 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- 725 AM CDT THU MAY 28 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN NORTH DAKOTA...WEST CENTRAL AND NORTHWEST MINNESOTA. .DAY ONE...TODAY AND TONIGHT THERE IS A RISK OF ISOLATED SEVERE STORMS MID TO LATE AFTERNOON AHEAD OF A COLD FRONT DROPPING SOUTHEAST. THE BEST CHANCE AREA IS FROM HALLOCK THROUGH GRAND FORKS AND FARGO TO LISBON FOR DEVELOPMENT BETWEEN 3 AND 5 PM. THE THUNDERSTORMS WILL THEN MOVE SOUTHEAST. COVERAGE OF ANY SEVERE WEATHER WILL BE ISOLATED. THE MAIN RISK IS LARGE HAIL AND WINDS TO 60 MPH. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. TEMPERATURES AROUND DAWN SATURDAY WILL BE IN THE 30S WITH A RISK OF FROST IN NORTHEASTERN NORTH DAKOTA AND THE NORTHWESTERN MINNESOTA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED. DTR
The Fargo/Grand Forks radar (KMVX), 132 km away, was scanning. The volume nearest the first event began at 15:58 UTC.
2 flash flood, 2 hail, 1 tornado. Local standard time, as filed.
Three to four inches of rain fell in a short duration, flooding ditches, fields, and farm access roads across portions of Westend and Homestead townships.
The tornado tracked for about two miles across southern Acton Township. Several medium to large cottonwood trees twelve to eighteen inches in diameter were snapped near the ground and numerous tree branches and limbs were broken off in shelterbelts along the path. Peak winds were estimated at 85 mph.
Three to four inches of rain fell in a short duration, flooding ditches, fields, and farm access roads across portions of eastern Sandoun Township.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Dakota in 2015Every state in 2015This day in weather historyThe tornado archive for North Dakota, 2015Warnings in North Dakota, May 2015
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: 568878, 571045, 568874, 568875, 571044.