textproduct: Bismarck

KEY MESSAGES

- Light snow combined with strong northwest winds will produce widespread blowing snow this morning and afternoon, with near- whiteout conditions at times in rural areas.

- A long duration of bitterly cold temperatures with dangerous to life-threatening wind chills is anticipated Thursday through the weekend.

DISCUSSION

Issued at 410 AM CST Wed Jan 21 2026

A clipper system with mid to surface trough axis across Manitoba early this morning will progress southeast through the day. At 4 AM CST, the cold front attendant to the clipper was beginning to enter northwest North Dakota. The front will quickly blast southeastward across the state this morning. Strong pressure rises and cold air advection are likely to mix 40-50 kt winds to the surface with the initial surge of colder air, with 30-40 kt gusts persisting through the afternoon in the well-mixed post frontal air mass with a tight surface pressure gradient. Most areas will see their daily maximum temperatures in the lower teens northeast to mid 20s southwest early this morning. By midday, expect most locations around 10 to 15 degrees with near-steady or falling temperatures through the afternoon.

The clipper will bring periods of mostly light snow across much of the state this morning. Closer to the cold front though, there is potential for pockets of moderate snowfall which has already been observed from southwest Saskatchewan to northeast Montana (quarter mile visibility at Swift Current and Plentywood) and can be seen on radar throughout that area. Several ingredients for snow squalls are forecast to be present across western and central North Dakota through the morning, but not convinced everything will line up perfectly to produce a warning criteria event. Nevertheless, the strong northwest winds will easily blow around any snow that has fallen within the last 24-36 hours. The worst visibility is expected to be associated with falling snow this morning (even in the absence of a true snow squall event), with near-whiteout conditions possible at times in rural areas. Our blowing snow model continues to support a widespread advisory event, with a gradual improvement in conditions through the afternoon. There is potential though for streams of snow showers and/or blowing snow associated with horizontal convective rolls this afternoon, diminishing from west to east by early evening. Total snow accumulations for today are forecast around one half to 2 inches.

No changes have been made to headlines for today, which include the Wind Advisory for the 4 southwest counties and a Winter Weather Advisory elsewhere. There could very well be a handful of gusts around 60 mph with the frontal passage across western North Dakota this morning, but model soundings strongly suggest gusts of that magnitude are only possible for an hour or two at any given location. Even though the 4 southwest counties are not under a Winter Weather Advisory, there is still potential for a period of impactful winter weather this morning, just of a shorter duration compared to elsewhere.

Our attention then turns to a well-advertised long-duration Arctic outbreak that is expected to produce dangerous to life- threatening conditions. The Arctic air mass is forecast to filter into the region this evening through Thursday. Sub-zero surface temperatures are forecast to spread from far north central North Dakota late this evening to the south and west through tonight. By late Thursday morning, temperatures are forecast to settle around zero southwest to as cold as 20 below near the Turtle Mountains and remain near those values through the day. The most extreme cold is then expected Thursday night through Friday, with low temperatures falling into the 20s and 30s below zero and highs on Friday limited to around 10 to 20 below for all but the far southwest. Climatological ensemble tools strongly support anomalously cold temperatures, even by January standards. The deterministic NBM continues to exhibit a warm bias compared to the full distribution that we believe to be a holdover from the milder Pacific air from earlier this month. We have therefore decreased both low temperatures Thursday night and high temperatures on Friday closer to the 50th percentile. This solution fits our expectations of a 1050-1055 mb surface high sliding into southern Saskatchewan Thursday night, with a ridge axis extending through western North Dakota where temperatures could easily bottom out in the 30s below zero.

Thursday will be breezy as the Arctic air moves in, with northwest winds around 15 to 25 mph. The rest of the forecast through the weekend contains lighter winds, but it won't take much to produce dangerous to life-threatening wind chills at the extremely cold forecast temperatures. Wind chills will begin falling to hazardous levels as early as late tonight across the north, with 30s to 40s below quickly spreading south through the day Thursday. There continues to be high confidence in Thursday night through Friday morning being the most dangerous period, with minimum wind chills forecast around 45 to 55 below zero, coldest across the north and into the James River Valley. The inherited Extreme Cold Watch for all areas north and east of the Missouri River remains in effect early Thursday morning through Sunday morning. We have also placed all areas to the south and west of the river in an Extreme Cold Watch for Thursday evening through Friday morning.

The low and high temperature forecasts, along with minimum wind chills, show only incremental improvement through the weekend. Heading into next week, there is high confidence in a northwest flow pattern but uncertainty whether western and central North Dakota will be closer to Arctic air, milder Pacific air, or along the baroclinic zone dividing the two. Cluster analysis focused over the Monday/Tuesday time frame shows around a 65 percent chance for temperatures returning closer to normal and a 35 percent chance for Arctic air persisting (though not as intense as late this week). The anticipated prevailing of northwest flow aloft could promote a few weak clipper passages this weekend through the middle of next week, but forecast uncertainty is too high to highlight any snow or wind potential at this time.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 410 AM CST Wed Jan 21 2026

Clipper storm system will move through the region today, bringing another surge of light accumulating snow through this morning. Strong northwest winds will also accompany this clipper, with gusts up to around 40 knots after 12Z west and after 15Z elsewhere. Falling and blowing snow can be expected at all terminals, with visibility reduced to IFR-LIFR, and at times approaching airport minimums, especially this morning. Conditions will improve this afternoon and evening as falling snow ends and winds start to slowly subside.

BIS WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 6 PM CST /5 PM MST/ this evening for NDZ001>005-009>013-017>023-025-031>037-042-045>048-050-051. Extreme Cold Watch from Thursday morning through Sunday morning for NDZ001>005-009>013-021>023-025-035>037-046>048-050- 051. Extreme Cold Watch from Thursday evening through Friday morning for NDZ017>020-031>034-040>045. Wind Advisory until 5 PM MST this afternoon for NDZ040-041-043- 044.