A strong low pressure system moving across the Northern Plains brought a prolonged period of strong winds to west and central North Dakota from the evening of the 19th through the afternoon of the 20th. The first round of the stronger winds impacted southwest North Dakota during the evening of the 19th along the initial pressure rises behind a cold front.
Every event with a place to put it; 28 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 BIS wrote it up.
A strong low pressure system moving across the Northern Plains brought a prolonged period of strong winds to west and central North Dakota from the evening of the 19th through the afternoon of the 20th. The first round of the stronger winds impacted southwest North Dakota during the evening of the 19th along the initial pressure rises behind a cold front. The second round of the stronger winds lasted through the morning hours and into the early afternoon of the 20th.
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 Sep 19, 2:24 PM CST, 4 hours 6 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BISMARCK ND 324 PM CDT MON SEP 19 2011 .SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT... THE MAIN FORECAST CONCERN FOR THE PERIOD WILL BE THE WINDS ACROSS WESTERN AND CENTRAL NORTH DAKOTA TONIGHT AND TUESDAY. OF SECONDARY CONCERN WILL BE THE PRECIPITATION CHANCES ASSOCIATED WITH THE STORM SYSTEM EXPECTED TO AFFECT THE AREA TONIGHT AND TUESDAY. WATER VAPOR IMAGERY SHOWED A SHORTWAVE TROUGH DIGGING ACROSS SOUTHERN ALBERTA AND INTO WESTERN MONTANA THIS AFTERNOON. ITS ATTENDANT FRONT WAS ROUGHLY LOCATED ALONG A LINE FROM MALTA TO LEWISTOWN TO HELENA MONTANA. THIS FRONT SHOULD SWEEP INTO WESTERN NORTH DAKOTA AFTER SUNSET. THE INITIAL ISALLOBARIC PUSH (4-6 MB PER 3 HOUR PRESSURE RISES) SHOULD ALLOW WINDS TO INCREASE RAPIDLY TO AROUND 40 MPH OVER THE WESTERN PORTIONS OF THE STATE...ESPECIALLY ACROSS SOUTHWESTERN NORTH DAKOTA BETWEEN 01Z- 02Z. AFTER THE INITIAL SURGE...THE SHORTWAVE WILL ENTER WESTERN NORTH DAKOTA BY 06Z AND GENERATE A SIGNIFICANT INCREASE IN PRECIPITATION CHANCES. POPS ARE BASICALLY STRATIFIED FROM CATEGORICAL NORTH...LIKELY CENTRAL...AND CHANCE SOUTH. LITTLE IF ANY THUNDERSTORM ACTIVITY IS EXPECTED. MAINLY LIGHT TO MODERATE SHOWER ACTIVITY IS EXPECTED. RAINFALL AMOUNTS SHOULD BE THE HIGHEST OVER BOTTINEAU AND ROLETTE COUNTIES WITH 1 INCH STORM TOTALS POSSIBLE. THE SHORTWAVE WILL THEN BECOME CLOSED OFF OVER EASTERN NORTH DAKOTA BY 12Z TUESDAY. AS IT DOES...THE STRONG PRESSURE GRADIENT COMBINED WITH THE STRONG SUBSIDENCE ON THE BACK SIDE OF THE LOW SHOULD ALLOW THE HIGHER WINDS ALOFT TO MIX TO THE SURFACE...GENERATING WIND GUSTS UP TO 60 MPH...ESPECIALLY IN THE HIGHER TERRAIN. AS A RESULT...UPGRADED THE HIGH WIND WATCH TO A HIGH WIND WARNING. THE WARNING WILL BE VALID OVER THE WEST FROM 00Z-18Z TUESDAY...AND OVER THE CENTRAL AND EASTERN CWA FROM 06Z- 24Z TUESDAY AS THE VERTICALLY STACKED LOW SLOWLY MEANDERS INTO MINNESOTA. AS THE LOW CONTINUES TO SHIFT EAST...PRECIPITATION CHANCES WILL DECREASE FROM WEST TO EAST TUESDAY THROUGH TUESDAY NIGHT. WINDS WILL ALSO DECREASE SIGNIFICANTLY OVERNIGHT WITH GOOD RADIATIONAL COOLING EXPECTED WEST. AS A RESULT...INTRODUCED PATCHY FOG IN THE FORECAST WEST FOR 09Z-13Z WEDNESDAY. && .LONG TERM...WEDNESDAY THROUGH NEXT MONDAY... AFTER THE PASSAGE OF THE STORM SYSTEM IN THE SHORT TERM FORECAST PERIOD...BROAD UPPER LEVEL RIDGING OVER THE ROCKIES WILL RESULT IN ANOTHER EXTENDED DRY PERIOD ACROSS WEST AND CENTRAL NORTH DAKOTA MID WEEK THROUGH NEXT WEEKEND...ALONG WITH TEMPERATURES MODERATING TO WELL ABOVE NORMAL VALUES BY THE END OF THE WORK WEEK AND INTO THE WEEKEND. && .AVIATION... STRONG AREA OF LOW PRESSURE WILL PUSH ACROSS NORTH DAKOTA TONIGHT INTO TOMORROW. INCREASING CLOUDS FROM WEST TO EAST ALONG WITH INCREASING CHANCES FOR PRECIPITATION CAN BE EXPECTED THROUGH THE TAF PERIOD. OVERALL...EXPECT VFR CONDITIONS TO PERSIST THROUGH MUCH OF THIS EVENING. LATER TONIGHT...LOW LEVEL CIGS ARE FORECAST TO INCREASE IN AERIAL COVERAGE ON THE BACKSIDE OF THE LOW...MAINLY REMAINING ABOVE IFR. VERY STRONG WINDS WILL DEVELOP ON THE BACKSIDE OF THE LOW TONIGHT AS WELL...GUSTING TO OVER 50KTS AT TIMES THROUGH 18-21Z TUES. ALSO IN THE NEAR TERM THROUGH 06Z...SCT TSRA ARE EXPECTED WITH STRONG WINDS THE MAIN THREAT. && .FIRE WEATHER... AS DESCRIBED IN THE SHORT TERM FORECAST DISCUSSION...STRONG NORTHWEST WINDS SUSTAINED UP TO 40 MPH WITH GUSTS UP TO NEAR 60 MPH ARE EXPECTED TO DEVELOP ON THE BACKSIDE OF A STRONG SURFACE LOW LATER TONIGHT AND INTO TUESDAY. THE GREATEST FIRE WEATHER CONCERN WILL BE ACROSS THE DRY FAR SOUTHWEST WHERE PERCENT GREEN VALUES ARE THE LOWEST AND SOME PARTIAL CLEARING THROUGH TUESDAY DAYTIME SHOULD ALLOW AFTERNOON RELATIVE HUMIDITY VALUES TO FALL TO NEAR 30 PERCENT. THE STRONG WINDS COUPLED WITH CURING FUELS WILL LEAD TO VERY HIGH FIRE DANGERS DESPITE RELATIVE HUMIDITIES ABOVE CRITICAL VALUES. WILL CONTINUE WITH THE FIRE WEATHER WATCH FOR FAR SOUTHWEST NORTH DAKOTA ON TUESDAY AND REASSESS FORECAST PARAMETERS LATER TONIGHT/EARLY TUESDAY MORNING FOR A POSSIBLE UPGRADE TO A RED FLAG WARNING. && .BIS WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 1 AM CDT /MIDNIGHT MDT/ TO 7 PM CDT /6 PM MDT/ TUESDAY FOR NDZ002>005-010>013-019>023-025-034>037-042- 045>048-050-051. HIGH WIND WARNING FROM 7 PM CDT /6 PM MDT/ THIS EVENING TO 1 PM CDT /NOON MDT/ TUESDAY FOR NDZ017-018-031>033-040-041-043-044. FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON FOR NDZ040-043. && TM...SHORT TERM NH...LONG TERM/AVIATION/FIRE WEATHER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BISMARCK ND 328 PM CDT MON SEP 19 2011 NDZ001>005-009>013-017>023-025-031>037-040>048-050-051-202030- 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- 328 PM CDT MON SEP 19 2011 /228 PM MDT MON SEP 19 2011/ 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...TONIGHT A HIGH WIND WARNING IS IN EFFECT FOR MOST OF WESTERN AND CENTRAL NORTH DAKOTA. PLEASE VISIT WWW.WEATHER.GOV/BIS FOR MORE DETAILS. WIDESPREAD RAIN SHOWERS WITH ISOLATED EMBEDDED THUNDERSTORMS WILL DEVELOP TONIGHT. HOWEVER...NO ORGANIZED SEVERE WEATHER IS ANTICIPATED. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY A HIGH WIND WARNING IS IN EFFECT FOR MOST OF WESTERN AND CENTRAL NORTH DAKOTA TUESDAY. PLEASE VISIT WWW.WEATHER.GOV/BIS FOR MORE DETAILS. THE COMBINATION OF VERY STRONG NORTHWEST WINDS AND VERY DRY VEGETATION WILL YIELD VERY HIGH FIRE DANGER ACROSS THE FAR SOUTHWEST ON TUESDAY...AND A FIRE WEATHER WATCH IS IN EFFECT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED. TM
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BISMARCK ND 716 PM CDT MON SEP 19 2011 NDZ017-200115- MCKENZIE- 616 PM MDT MON SEP 19 2011 ...SPECIAL WEATHER STATEMENT... AT 612 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER EAST CENTRAL RICHLAND COUNTY MONTANA... MOVING EAST AT 50 MPH. WINDS UP TO 50 MPH...OCCASIONAL CLOUD TO GROUND LIGHTNING...ARE POSSIBLE WITH THIS STORM. * THE THUNDERSTORM WILL BE NEAR... THEODORE ROOSEVELT NATIONAL PARK NORTH BY 700 PM MDT... GUSTY WINDS MAY CAUSE SMALL BRANCHES TO BE BLOWN DOWN...AND LOOSE OBJECTS TO BLOW AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED. ABELING
The national radar mosaic for the moment the first event began.
31 high wind. Local standard time, as filed.
Measured wind gust from the Beach Automated Weather Observing System site.
Measured sustained winds from the Fryburg Road Weather Information System (RWIS) site.
Measured wind gust from the Hettinger Automated Surface Observing System site.
Estimated wind gusts near 60 mph occurred across Hettinger County.
Estimated wind gusts near 60 mph occurred across Slope County.
Estimated wind gusts near 60 mph occurred across Bowman County.
Measured sustained winds from the Grassy Butte Road Weather Information System (RWIS) site.
Estimated sustained winds near 40 mph occurred across Dunn County.
Estimated wind gusts near 60 mph occurred across Burke County.
Sustained winds of 42 mph were measured at the Remote Automated Weather Station at Tatanka Prairie.
Estimated sustained winds up to 40 mph occurred across Grant County.
Estimated sustained winds up to 40 mph occurred across Morton County.
Estimated sustained winds up to 40 mph occurred across Oliver County.
Estimated sustained winds up to 40 mph occurred across Mercer County.
Estimated sustained winds up to 40 mph occurred across McLean County.
Estimated sustained winds up to 40 mph occurred across Burleigh County.
Estimated sustained winds up to 40 mph occurred across Emmons County.
Estimated sustained winds up to 40 mph occurred across Kidder County.
Measured sustained winds from the Denhoff Road Weather Information System (RWIS) site.
Estimated sustained winds up to 40 mph occurred across McHenry County.
Estimated sustained winds up to 40 mph occurred across Rolette County.
Estimated sustained winds up to 40 mph occurred across Pierce County.
Estimated sustained winds up to 40 mph occurred across Wells County.
Estimated sustained winds up to 40 mph occurred across Logan County.
Measured sustained winds from the Wishek Road Weather Information System (RWIS) site.
Estimated sustained winds up to 40 mph occurred across Dickey County.
Estimated sustained winds up to 40 mph occurred across LaMoure County.
Measured sustained winds from the Medina Road Weather Information System (RWIS) site.
Estimated sustained winds up to 40 mph occurred across Foster County.
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, September 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: 335918, 335916, 335911, 335912, 335913, 335914, 335917, 335919, 335921, 335922, 335924, 338745, 338747, 338749, 338750, 338752, 338753, 338754, 338755, 338756, 338757, 338758, 338759, 338760, 338761, 338762, 338763, 338764, 338765, 338768, 338770.