An area of thunderstorms stretching from far southeast Montana towards southwest South Dakota developed ahead of an upper level trough, which moved to the northeast towards North Dakota. As the storms pushed into North Dakota, they encountered an atmosphere of elevated instability and strong deep layer shear.
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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.
An area of thunderstorms stretching from far southeast Montana towards southwest South Dakota developed ahead of an upper level trough, which moved to the northeast towards North Dakota. As the storms pushed into North Dakota, they encountered an atmosphere of elevated instability and strong deep layer shear. Strong and damaging wind gusts quickly became the key threat with these storms as they progressed to the northeast, though a few storms did produce large hail, with the largest hail being half-dollar size in McLean County. Multiple events of wind gusts over 70 mph occurred. The strongest wind gust estimated at 100 mph occurred in far northwest Kidder County, where neighboring farmsteads sustained heavy damage with a destroyed mobile home and grain bin, a severely damaged shop building, and multiple large trees either uprooted or snapped.
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 4, 4:36 PM CST, 1 hour 4 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Bismarck ND 536 PM CDT Mon Sep 4 2023 .UPDATE... Issued at 532 PM CDT Mon Sep 4 2023 Severe thunderstorm watch has been issued for parts of far southwest and south central North Dakota, as well as much of the James River Valley through this evening. The main threat continues to be very strong thunderstorm winds, with peak gusts ranging from 70 to 90 mph, with the best chance of occurrence from Mobridge, SD northeast through Jamestown, associated with a line of storms moving into a more favorable environment and as a potent mid level low swings east across the Dakotas. && .SHORT TERM...(This Evening through Tuesday) Issued at 215 PM CDT Mon Sep 4 2023 Current surface analysis places low over Manitoba with a trough extending southward through the northern plains, while a cold front stretches to the southwest of the low, just nudging into extreme northwest North Dakota into eastern Montana. Ahead of the front, temperatures have warmed mainly into the 80s and lower 90s, while behind the front wildfire smoke is notably dropping visibilities, with temperatures in the 50s and 60s. Upper level analysis places staunch trough with a slightly negative tilt stretching through central Montana into western Wyoming. A variety of notable short waves swinging around the trough are sliding up southwest flow which stretches through our area. A few rain showers behind the aforementioned cold front are trying to work their way towards northwest North Dakota, but the start of the main show that will be affecting us is a line of storms stretching from far southeast Montana through northeast Wyoming into far southwest South Dakota. For late this afternoon into tonight, aforementioned area of storms to the southwest will continue its approach. Latest timing of the storms bring them to the far southwest North Dakota border around 23Z (5 PM MDT), for which most CAMs have been pretty consistent with through the day. As the storms lift towards our area, they will encounter an environment with CAPE values of 1000-2000 J/Kg and about 40 to 50 kts of deep layer shear, all plenty for severe potential and large hail, particularly if we get a few stray storms developing ahead of the main line. What continues to catch our eye, though, is the potential for strong damaging wind gusts. Forecast parameters for wind potential continue to be on par with what was previously discussed early this morning with 0-3KM shear values in the 25 to 35 kt range, and DCAPE values of 1000+ J/kg. So, much of southwest and central North Dakota are in play for severe weather this evening, but the corridor of greatest concern continues to be south central North Dakota into portions of southwest where the greatest severe parameters are lining up. Therefore, will continue to message potential for 70 mph gusts with an isolated 80 mph possible. Severe threat wanes and exits by around 06Z, but showers and tamer thunderstorms continue though the overnight into Tuesday before gradually diminishing and departing the area. As for rainfall amounts, NBM probabilities continue to click up, with now a 50 to 80 percent chance of seeing an inch of rainfall tonight through Tuesday over much of southwest and south central North Dakota, The greatest values are around Bismarck stretching towards Glen Ullin, Hettinger, and Fort Yates, where, when looking at potential for 2 inches, a 30 to 50 percent chance exists. Now, on to a separate concern, smoke. Behind the advancing cold front which is now pushing into far northwest North Dakota, visibility has notably dropped off along with air quality as the next batch of wildfire smoke makes its way into the area. Therefore, have brought smoke into the area in line with latest HRRR near surface smoke guidance. There is still some question as to how the smoke will interact with the anticipated rainfall, but earlier this summer we had an event where notable smoke lingered around while thunderstorms were occurring. Continued having smoke in the area through Tuesday/Tuesday night. .LONG TERM...(Wednesday through Monday) Issued at 215 PM CDT Mon Sep 4 2023 Near to below average temperatures are expected through this time period. Occasional shower/storm chances develop over the area from time to time, but based on latest parameters concern for severe is low. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon) Issued at 215 PM CDT Mon Sep 4 2023 Thunderstorms will move into western North Dakota late this afternoon, spreading east this evening. A few of these storms may become severe with large hail and strong wind gusts. Localized MVFR to IFR visibilities will be possible under any of the heavier showers or storms. IFR to MVFR ceilings will also move into the southwest and south central late in the period as a steadier rain settles in. In addition, areas of smoke will move into northwest North Dakota this afternoon, spreading southeast as we go into tonight and Tuesday. This may drop visibility to MVFR and IFR levels. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && UPDATE...NH SHORT TERM...JJS LONG TERM...JJS AVIATION...JJS
Hazardous Weather Outlook National Weather Service Bismarck ND 212 PM CDT Mon Sep 4 2023 NDZ001-002-009-051915- Divide-Burke-Williams- 212 PM CDT Mon Sep 4 2023 This Hazardous Weather Outlook is for portions of northwest North Dakota. .DAY ONE...This Afternoon and Tonight Thunderstorms are possible. Severe weather is not expected. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. NDZ003>005-010>013-017-018-031-032-051915- Renville-Bottineau-Rolette-Mountrail-Ward-McHenry-Pierce-McKenzie- Dunn-Golden Valley-Billings- 212 PM CDT Mon Sep 4 2023 /112 PM MDT Mon Sep 4 2023/ This Hazardous Weather Outlook is for portions of north central North Dakota, northwest North Dakota, and southwest North Dakota. .DAY ONE...This Afternoon and Tonight Thunderstorms are possible this morning. Severe weather is not expected. Isolated severe storms are possible late this afternoon and into the evening. The primary threats will be one inch diameter hail and wind gusts to 60 mph. In addition, some storms could contain heavy rainfall tonight into Tuesday morning. This could lead to some localized flooding concerns. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed this afternoon and evening. Please report any severe weather, which includes flooding, to the National Weather Service in Bismarck. NDZ019>023-025-033>037-040>048-050-051-051915- Mercer-Oliver-McLean-Sheridan-Wells-Foster-Stark-Morton-Burleigh- Kidder-Stutsman-Slope-Hettinger-Grant-Bowman-Adams-Sioux-Emmons- Logan-La Moure-McIntosh-Dickey- 212 PM CDT Mon Sep 4 2023 /112 PM MDT Mon Sep 4 2023/ This Hazardous Weather Outlook is for portions of south central North Dakota, southeast North Dakota, and southwest North Dakota. .DAY ONE...This Afternoon and Tonight Scattered severe storms are possible late this afternoon and into the evening. The primary threat will be one-inch diameter hail and damaging winds to 70 mph. An isolated storm or two may produce wind gusts of 80 mph. Also, a few of the initial thunderstorms could produce ping pong ball size hail. In addition, some storms could contain heavy rainfall tonight into Tuesday morning. This could lead to some localized flooding concerns. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed this afternoon and evening. Please report any severe weather, which includes flooding, to the National Weather Service in Bismarck.
Special Weather Statement
National Weather Service Bismarck ND
605 PM CDT Mon Sep 4 2023
NDZ018-019-033-034-042330-
Stark ND-Mercer ND-Morton ND-Dunn ND-
605 PM CDT Mon Sep 4 2023
...A STRONG THUNDERSTORM WILL IMPACT PORTIONS OF SOUTHEASTERN DUNN,
NORTHWESTERN MORTON, EASTERN STARK AND SOUTHWESTERN MERCER COUNTIES
THROUGH 630 PM CDT/530 PM MDT/...
At 605 PM CDT/505 PM MDT/, strong thunderstorms are located over
Richardton, or 22 miles east of Dickinson, moving northeast at 35
mph.
HAZARD...Wind gusts to 50 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
This storm will remain over mainly rural areas of southeastern Dunn,
northwestern Morton, eastern Stark and southwestern Mercer Counties.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Severe Thunderstorm Watch remains in effect until 1100 PM CDT/1000
PM MDT/ for south central North Dakota.
&&
LAT...LON 4685 10268 4736 10217 4728 10171 4724 10174
4724 10177 4721 10176 4665 10220
TIME...MOT...LOC 2305Z 208DEG 31KT 4689 10230
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH
MDJThe Bismarck radar (KBIS), 98 km away, was scanning. The volume nearest the first event began at 23:38 UTC.
20 thunderstorm wind, 3 hail. Local standard time, as filed.
Thunderstorm wind gusts were estimated by a trained spotter.
Thunderstorm wind gusts were estimated by a trained spotter.
Thunderstorm wind gusts were estimated by the public.
Wind gusts were estimated by a trained spotter.
A power line was blown down.
Several trees blew down at Cross Ranch State Park, and many other branches were blown down. Upon inspection of the trees that blew down, some rot was noted.
Thunderstorm wind gusts were estimated by a trained spotter.
Several tree branches, along with a few trees, were knocked down in and around the Bismarck area. Two vehicles were totaled as a tree fell on them at Skyway Park Village.
A small Park Model mobile, which was on blocks and anchored down, was completely destroyed, with the undercarriage separating from the unit, though the deck remained in its spot with a grill still on it. A 55 gallon barrel of steel scrap was blown over and rolled. Multiple three foot diameter cottonwood trees were damaged, with some uprooted and a few older ones snapped. About one-quarter mile to the east of this location a grain bin was blown across a road, and a shop wall was blown out. Windbreak panels were toppled, with one tossed and flipped over. All damage was blown toward the north and east, the direction the storm was moving.
Thunderstorm wind gusts were estimated by a trained spotter.
A large evergreen tree blew over.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Dakota in 2023Every state in 2023This day in weather historyWarnings in North Dakota, September 2023
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: 1139307, 1139305, 1139310, 1139311, 1139314, 1139315, 1139306, 1139309, 1139312, 1139313, 1139316, 1139317, 1139319, 1139320, 1139321, 1139324, 1139326, 1139340, 1141334, 1139359, 1141303, 1139361, 1139362.