Tornado Watch number 290 and Severe Thunderstorm Watch number 291 were in effect during this event. Strong afternoon destabilization occurred north and east of an area of low pressure situated over southwest North Dakota May 22nd.
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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 BIS wrote it up.
Tornado Watch number 290 and Severe Thunderstorm Watch number 291 were in effect during this event.
Strong afternoon destabilization occurred north and east of an area of low pressure situated over southwest North Dakota May 22nd. The trigger for thunderstorm development was a strong upper level jet streak advecting northeast across the Rockies and into the Northern Plains. While a strong capping inversion was in place in the low's warm sector, a weaker cap existed over northern North Dakota, where convection first initiated late in the afternoon over the far northwest. Additional strong to severe thunderstorms developed during the evening across the north central and from the south central into the James River Basin. Severe hail, severe thunderstorm winds, and two confirmed EF0 tornadoes occurred during this event.
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 Bismarck, ND wrote its last area forecast discussion before the first event at May 22, 12:58 PM CST, 2 hours 57 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BISMARCK ND 158 PM CDT TUE MAY 22 2012 .SHORT TERM...THIS AFTERNOON THROUGH TONIGHT... MAIN FOCUS IS ON THE SEVERE WEATHER POTENTIAL. LATEST SURFACE ANALYSIS SHOWS A WEST TO EAST WARM FRONT DRAPED OVER CENTRAL NORTH DAKOTA...FROM NEAR TROTTERS TO BEULAH...AND EAST INTO FESSENDEN. HELICITY AND SHEAR INCREASING OVER THE NORTHWEST...WITH LCL HEIGHTS LOWERING THROUGH THE AFTERNOON ALONG AND NORTH OF THE WARM FRONT. SPC HAS INCREASED THE TORNADO THREAT TO 5 PERCENT ACROSS NORTH CENTRAL NORTH DAKOTA THIS AFTERNOON AND EVENING. NAM/GFS SOUNDINGS STILL SUGGEST THAT LARGE HAIL...DAMAGING WINDS...AND HEAVY RAINFALL THE PRIMARY THREATS. SOUNDINGS EXHIBIT LARGE CAPE IN THE HAIL GROWTH ZONE WITH A SOMEWHAT DRY SOUNDING BENEATH 700MB. THUS THINKING IS INITIALLY THAT DAMAGING WINDS AND HAIL WOULD OCCUR FIRST WITH CLOUD BASES LOWERING AND THEN SUPPORTING HEAVY RAINFALL POTENTIAL IN SOME AREAS. PWATS OF 1.48 INCHES WITH A K-INDEX OF 46 AT KBIS BY 00Z WEDNESDAY. THINKING IS WE MAY NEED TO SECTORIZE THE FORECAST AREA INTO TWO AREAS/THREATS LATER THIS AFTERNOON AND EVENING. LARGE HAIL/DAMAGING WINDS/HEAVY RAINFALL/ISOLATED TORNADOES ALONG AND NORTH OF THE WARM FRONT...OVER NORTH CENTRAL NORTH DAKOTA. THE SECOND THREAT WOULD BE SOUTH OF THE WARM FRONT AND AHEAD OF THE COLD FRONT...COVERING SOUTH CENTRAL AND SOUTHEAST NORTH DAKOTA WITH LARGE HAIL/DAMAGING WINDS/HEAVY RAINFALL. THE RAPID REFRESH/HRR MODEL SUGGESTS A LINE OF THUNDERSTORMS FORMING BETWEEN WILLISTON AND MINOT BY MID AFTERNOON...AND THEN QUICKLY FILLING IN SOUTH TO BISMARCK BY 00Z. WILL CONTINUE TO MONITOR AND AWAIT A POTENTIAL WATCH FROM SPC. UPDATES FORTHCOMING...STAY TUNED. .LONG TERM...WEDNESDAY THROUGH TUESDAY... EXPECT COOLER CONDITIONS ON WEDNESDAY WITH ISOLD SHOWERS POSSIBLE OVER THE FAR NORTH IN THE VICINITY OF A COLD FRONT. BY THURSDAY...THIS FRONT IS EXPECTED TO DROP SOUTH THROUGH THE FORECAST AREA...WITH ASSOCIATED SHOWERS AND ISOLATED THUNDERSTORMS. AN EVEN COOLER AIRMASS BEHIND THE BOUNDARY WILL KEEP AFTERNOON HIGHS IN THE 50S AND 60S. RELATIVELY COOL CONDITIONS WILL CONTINUE THROUGH THE WEEKEND. SHOWERS AND STORMS WILL BECOME MORE WIDESPREAD BY LATE FRIDAY INTO SUNDAY AS SOUTHWEST FLOW ALOFT DEVELOPS AND EVENTUALLY A SURFACE BOUNDARY PUSHES NORTH INTO THE REGION. HAVE MAINTAINED PERIODS OF HIGH CHANCE TO LIKELY POPS. && .AVIATION...22/18Z ISSUANCE... FOLLOWED NAM FOR CONVECTIVE TRENDS THIS AFTERNOON AND TONIGHT. HAVE FRAMED A TWO HOUR TEMPO WINDOW FOR HIGHEST THREAT OF STRONG STORMS...BEGINNING AS EARLY AS 21Z AT KISN...AND TRANSITIONING EASTWARD...BEGINNING AT 01Z AT KJMS. STRONG WINDS AND LARGE HAIL WILL BE POSSIBLE...BUT WITH UNCERTAINTY AS TO THE EVENTUAL LOCATION OF STRONG/SEVERE STORMS...WILL NOT HIGHLIGHT IN TAFS AT THIS TIME AND COVER WITH UPDATES THROUGH THE AFTERNOON/EVENING. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...KS AVIATION...RK
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BISMARCK ND 450 PM CDT TUE MAY 22 2012 NDZ001>005-009>013-017>023-025-031>037-040>048-050-051-232200- DIVIDE-BURKE-RENVILLE-BOTTINEAU-ROLETTE-WILLIAMS-MOUNTRAIL-WARD- MCHENRY-PIERCE-MCKENZIE-DUNN-MERCER-OLIVER-MCLEAN-SHERIDAN-WELLS- FOSTER-GOLDEN VALLEY-BILLINGS-STARK-MORTON-BURLEIGH-KIDDER- STUTSMAN-SLOPE-HETTINGER-GRANT-BOWMAN-ADAMS-SIOUX-EMMONS-LOGAN- LA MOURE-MCINTOSH-DICKEY- 450 PM CDT TUE MAY 22 2012 /350 PM MDT TUE MAY 22 2012/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL NORTH DAKOTA...NORTHWEST NORTH DAKOTA...SOUTH CENTRAL NORTH DAKOTA...SOUTHEAST NORTH DAKOTA AND SOUTHWEST NORTH DAKOTA. .DAY ONE...REST OF THIS AFTERNOON AND TONIGHT STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON INTO TUESDAY EVENING FROM NORTHWEST NORTH DAKOTA...INCLUDING DIVIDE AND WILLIAMS COUNTIES THROUGH NORTH CENTRAL...CENTRAL AND EASTERN PORTIONS OF THE STATE. THE THREAT FOR SEVERE THUNDERSTORMS WILL BE LOW ACROSS SOUTHWESTERN NORTH DAKOTA. THE MAIN SEVERE WEATHER THREATS ARE LARGE HAIL...STRONG WIND GUSTS GREATER THAN 60 MPH AND ISOLATED TORNADOES. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... PLEASE RELAY REPORTS OF SEVERE WEATHER OR STORM DAMAGE TO THE NATIONAL WEATHER SERVICE IN BISMARCK AT 701-223-4582. JNS
The national radar mosaic for the moment the first event began.
18 hail, 4 thunderstorm wind, 2 tornado. Local standard time, as filed.
This storm report stated that tree branches up to six inches in diameter were broken off by the strong winds.
This tornado touched down in the open country of Divide County, along the international border. There were no reports of damage associated with this tornado.
Professional storm chasers reported this brief tornado. There were no reports of damage so the tornado is rated EF0.
The hail resulted in damage to vehicles.
The hail damaged a car.
The trained spotter reported no damage.
Large hail accompanied the strong winds.
The strong winds broke small tree branches.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Dakota in 2012Every state in 2012This day in weather historyThe tornado archive for North Dakota, 2012Warnings in North Dakota, 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: 376928, 378032, 381206, 376904, 376905, 376906, 376907, 376908, 376909, 376911, 376910, 376912, 376913, 376914, 376915, 376925, 376916, 376926, 376927, 376918, 376917, 376919, 376920, 376921.