A frontal boundary moved into extreme northwest Minnesota by the early afternoon of July 22nd, helping to initiate a few thunderstorms just to the north of the Pembina/St. Vincent area.
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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.
A frontal boundary moved into extreme northwest Minnesota by the early afternoon of July 22nd, helping to initiate a few thunderstorms just to the north of the Pembina/St. Vincent area. These storms tracked to the east over the next several hours and affected portions of the Lake of the Woods and Baudette areas with large hail. There was then a break of several hours before more thunderstorms fired up along the same boundary, which by late afternoon extended from the Lake of the Woods to Hillsboro, North Dakota, to near Mobridge, South Dakota. These thunderstorms also tracked to the east while additional storms flared up across portions of west central Minnesota. These storms predominantly produced large hail, but isolated strong winds also occurred.
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 Jul 22, 9:16 AM CST, 2 hours 29 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 1016 AM CDT SUN JUL 22 2012 .DISCUSSION... HAD SOME CONVECTION FIRE UP JUST NORTH OF THE PEMBINA/ST. VINCENT AREA WHICH IS SLOWLY DRIFTING TO THE EAST. THIS MAY CLIP PORTIONS OF NORTHEAST ROSEAU OR NORTHERN LAKE OF THE WOODS COUNTIES IN THE NEXT COUPLE OF HOURS BEFORE IT MOVES EAST OF THE AREA. WENT AHEAD AND ADDED SOME ISOLATED THUNDER CHANCES FOR THESE AREAS TO COVER THIS POTENTIAL. OTHERWISE LOTS OF SUN ACROSS THE AREA AND WITH GUIDANCE SHOWING THE HEAT CONTINUING ALSO BUMPED UP HIGHS ACROSS SOUTHEAST ND JUST A BIT. AS FAR AS SEVERE POTENTIAL THIS AFTERNOON THERE ARE STILL QUESTIONS. SEVERAL OF THE NEW 12Z MODELS HAVE COME IN LOOKING MUCH DRIER NOW. SFC FRONT/TROUGH HAS NOW PUSHED INTO THE RED RIVER VALLEY. WINDS ARE STILL PRETTY WEAK ALONG THIS BOUNDARY SO IT IS NOT PROVIDING MUCH CONVERGENCE. NOT MUCH COOLING BEHIND IT EITHER SO IT MAY BE MORE OF A TROUGH LINE AND IS THEREFORE NOT LIKELY TO BE A STRONG FOCUSING MECHANISM FOR SEVERE WEATHER. HOWEVER WITH HIGHS IN THE LOW 90S AND DEW POINTS AROUND 70F THERE IS A LOT OF CAPE. THE BEST SOURCE OF LIFT IS THE SHORT WAVE APPROACHING THE MANITOBA LAKES REGION. DOWN TOWARD THE ND/SD BORDER MID LEVEL TEMPS MAY CAP ANY CONVECTION. SO STILL A LOT OF UNCERTAINTY BUT COVERAGE WOULD PROBABLY BE ISOLATED AT BEST. DO NOT REALLY EXPECT MUCH TO GET GOING UNTIL MID TO LATE AFTERNOON IF AT ALL AND LAST INTO EARLY EVENING. THERE IS NO LOW LEVEL JET TO KEEP THINGS GOING AFTER THE LOSS OF HEATING. && .AVIATION... VFR CONDITIONS WILL CONTINUE THROUGHOUT THE PERIOD. LIGHT SOUTHERLY WINDS WILL PICK UP AND SHIFT TO THE NORTHWEST AS A FRONT COMES THROUGH. THERE COULD BE SOME CONVECTIVE ACTIVITY NEAR THE FRONT DURING THE 21 TO 03Z TIME FRAME...MAINLY NEAR KBJI OR KFAR. HOWEVER...THERE IS SOME QUESTION AS TO HOW WIDESPREAD SO WILL KEEP MENTION OUT OF THE TAFS FOR NOW. && .PREV DISCUSSION... /ISSUED 259 AM CDT SUN JUL 22 2012/ SHORT TERM... MAIN CONCERN FOR THE SHORT TERM CONTINUES TO BE CONVECTIVE CHANCES. WV LOOP SHOWS A FAIRLY VIGOROUS SHORTWAVE MOVING THROUGH SASKATCHEWAN...AND MODELS ARE ALL IN FAIRLY DECENT AGREEMENT ON TAKING THE FEATURE ACROSS MANITOBA TODAY AND INTO ONTARIO. THIS SHOULD HELP PUSH ANOTHER SFC TROUGH AND WEAK FRONTAL BOUNDARY INTO THE CWA THROUGHOUT THE DAY. WINDS SHIFTING TO THE SOUTH AHEAD OF THE FRONT SHOULD HELP DEW POINTS RETURN TO THE 60S AND WITH TEMPS GETTING BACK TO THE UPPER 80S TO LOW 90S...CAPE VALUES OF 2000-3000 J/KG WILL BE POSSIBLE AS THE BOUNDARY COMES THROUGH. THERE IS THE QUESTION OF THE CAP AND MODELS ALL HOLD OFF ON DEVELOPMENT ALONG THE FRONT UNTIL LATE AFTERNOON/EVENING. MADE A FEW MINOR TWEAKS TO GOING POPS...BUT OVERALL KEPT THE TREND OF 20-30 PERCENT ALONG THE BOUNDARY FOR THE AFTERNOON AND EVENING HOURS. BULK SHEAR VALUES ARE NOT PARTICULARLY IMPRESSIVE OVER THE SOUTHERN CWA...BUT GET UP TO AROUND 45 KTS OR SO NEAR LAKE OF THE WOODS...SO THE NORTHEASTERN COUNTIES WILL HAVE THE BEST CHANCE OF SEEING SOMETHING SEVERE. THERE SHOULD BE SOME DECENT COLD AIR ADVECTION TONIGHT BEHIND THE DEPARTING BOUNDARY. A FEW SHOWERS MAY LINGER IN THE FAR SOUTH LATE TONIGHT BUT OVERALL THINK THAT TONIGHT AND TOMORROW SHOULD BE PRETTY QUIET WITH HIGH PRESSURE BUILDING IN. MONDAY SHOULD BE FAIRLY SIMILAR TO SATURDAY WITH HIGHS IN THE 80S AND LOWER DEWPOINTS BEHIND THE FRONTAL BOUNDARY. EASTERLY WINDS WILL BEGIN TO PICK UP MONDAY NIGHT AS SFC TROUGH DEVELOPS ALONG THE MT BORDER. SOME STRAY CONVECTIVE ACTIVITY MAKING IT INTO THE FAR SOUTHERN OR WESTERN CWA IS NOT OUT OF THE QUESTION MONDAY NIGHT OR TUESDAY...SO KEPT LOW POPS GOING IN THOSE AREAS. A BETTER CHANCE WILL ARRIVE TUESDAY NIGHT AS A WEAK SHORTWAVE COMES OVER THE TOP OF THE UPPER RIDGE INTO THE NORTHERN PLAINS...WITH AN EVEN STRONGER UPPER LOW OVER SASKATCHEWAN. CONTINUED TO KEEP HIGH CHANCE POPS GOING AS A DECENT SFC TROUGH MOVES OUT INTO THE CWA. LONG TERM (WEDNESDAY-SATURDAY)... THE MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE PRECIP CHANCES MAINLY DURING THE WED/THU TIMEFRAME. THE 00Z GFS AND ECMWF ARE IN FAIRLY GOOD AGREEMENT EARLY IN THE PERIOD WITH THE PROGRESSION OF A FAIRLY STRONG SHORTWAVE TROUGH SOUTHEAST ACROSS THE CANADIAN PRAIRIES...WITH THE GEM SLOWER. THE GFS/ECMWF START TO BRING THE SFC TROUGH/COLD FRONT ACROSS THE AREA ON WED...WITH SOME SHOWERS/STORMS EXPECTED. THE LOW-LEVEL JET/WARM ADVECTION WILL BE FOCUSED MORE ACROSS EASTERN MN...SO STILL UNCERTAINTY ON WHERE THE PRECIP WILL BE FOCUSED. IF THE SLOWER GEM SOLUTION VERIFIED...THE COLD FRONT WOULD NOT PUSH THROUGH UNTIL THUR. KEPT THE HIGHEST POPS ACROSS THE NORTHERN AND EASTERN PARTS OF THE FORECAST AREA WED NIGHT INTO THU...CLOSER TO THE BETTER FORCING ASSOCIATED WITH THE UPPER LOW...ALTHOUGH QUITE A BIT OF UNCERTAINTY EXISTS DUE TO MODEL DIFFERENCES DURING THESE PERIODS. DEPENDING ON CLOUD COVER AND PRECIP...TEMPS SHOULD CONTINUE TO BE AT OR A BIT ABOVE NORMAL FOR WED AND THU. COOLER AND DRIER AIR SHOULD PUSH IN BEHIND THE SYSTEM LATER THU AND FRI...WITH HIGH PRESSURE BUILDING IN. TEMPS ON FRI MAY REMAIN IN THE 70S TO LOW 80S...WITH A BIT OF RECOVERY FOR SATURDAY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && GODON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND FORKS ND 556 AM CDT SUN JUL 22 2012 MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024- 026>030-038-039-049-052>054-231100- 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- 556 AM CDT SUN JUL 22 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN NORTH DAKOTA...WEST CENTRAL AND NORTHWEST MINNESOTA. .DAY ONE...TODAY AND TONIGHT THERE IS A CHANCE FOR SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING. THE BEST CHANCES FOR STRONG TO SEVERE STORMS WILL BE EAST OF A PARK RAPIDS TO FLAG ISLAND LINE WITH WEAKER STORMS PRODUCING MAINLY LIGHTNING AND BRIEF DOWNPOURS FURTHER SOUTH AND WEST. THE STRONG TO SEVERE STORMS OVER THE LAKE OF THE WOODS TO ITASCA STATE PARK REGION COULD PRODUCE LARGE HAIL AND DAMAGING WINDS. STORMS WILL MOVE OFF TO THE SOUTH AND EAST OVERNIGHT AS A COLD FRONT PUSHES THROUGH THE AREA. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY THERE WILL BE ADDITIONAL CHANCES FOR THUNDERSTORMS TUESDAY NIGHT THROUGH FRIDAY. AT THIS TIME EXACTLY HOW STRONG STORMS WILL BECOME IS UNCERTAIN...SO STAY TUNED FOR FURTHER UPDATES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED EAST OF A PARK RAPIDS TO FLAG ISLAND LINE THIS AFTERNOON AND EVENING. JR
The national radar mosaic for the moment the first event began.
7 hail, 1 thunderstorm wind. Local standard time, as filed.
Large hail was observed over open water on the Lake of the Woods, just west of Garden Island.
The hail fell at the Sportsman's Lodge.
The hail fell at the Lake of the Woods campground.
Several large trees were either snapped or uprooted along the north shore of Lake Ida. The trees varied in size from one to 2.5 feet in diameter.
The time was estimated from radar.
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, July 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: 385783, 385779, 385778, 385780, 385784, 385782, 385781, 385785.