textproduct: Bismarck

KEY MESSAGES

- Snow will fall across most of western and central North Dakota tonight through Tuesday afternoon. The highest snow amounts are forecast to be along a line from Crosby to Garrison to Jamestown, where 4 to 9 inches of snow are possible.

- Strong northwest winds, with gusts around 45 mph, are forecast late tonight through Tuesday. Snow combined with the strong winds will cause areas of blowing and drifting snow.

- There remains increased confidence in a very cold and possibly snowy pattern after Thanksgiving, which could lead to additional travel concerns for the end of the holiday weekend.

UPDATE

Issued at 129 AM CST Tue Nov 25 2025

There were no major modifications to the forecast with this update. See updated Aviation Discussion below.

Strong mid level S/WV moving into the western Dakotas early this morning, and will continue east-southeast and closing off over South Dakota later this morning. Area of sfc low pressure across central SD, with an inverted trough extending back northwest across south central into western North Dakota. Strong cold frontal boundary continues to advance southward in the wake of the trough, and will changeover and lingering rain to all snow over the next few hours.

UPDATE Issued at 1016 PM CST Mon Nov 24 2025

At 10 PM CST, a deepening surface low was analyzed over west central North Dakota, just downstream of the mid level trough. Precipitation has become much more widespread across the western half of the state this evening, as anticipated. The rain/snow transition line is generally located along Highway 200 from around Grassy Butte to Washburn, and continues to advance southward. 00Z high-resolution guidance continues to paint a swath of +6" from around Crosby to Garrison to Wahpeton, which is a slight shift south over central and eastern North Dakota. But these amounts may be slightly overdone when considering initial melting on contact (until snowfall rates sufficiently increase) and compaction. The latest NBM mean snowfall also now shows a 6-8 inch swath from around Sheridan to LaMoure Counties. This may be the area most likely for a potential upgrade to a Winter Storm Warning in future updates.

UPDATE Issued at 726 PM CST Mon Nov 24 2025

As of 7 PM CST, snow was falling across northwest North Dakota as far east as New Town and as far south as Killdeer, but not yet over all of McKenzie County. Areas from around Crosby to Williston have been observing snow for around 2 to 3 hours. Recent webcam imagery from that part of the state implies moderate to heavy snow at times, and there is now accumulation on roadways.

The major forecast challenge for tonight will be whether any parts of the state require an upgrade to a Winter Storm Warning. The signal for mesoscale banding is not that prevalent, with just a transient area of 850 mb frontogenesis projected by the RAP from northwest to central North Dakota later this evening. The intense synoptic scale lift combined with a deep layer of steep mid level lapse rates, including through the dendritic growth zone, may be sufficient to produce a swath of +6 inches on its own. But there are still several factors contributing uncertainty to forecast snow amounts. One is how quickly rain will change over to snow. Recent rapid-refresh guidance is a little too slow on this transition compared to what is being observed, which could drive snow totals higher. The progressive nature of this system has been discussed as a deterring factor for higher end amounts, but recent CAMs have been consistent in painting and oblong precipitation shield whose major axis is closely aligned with the system's trajectory. There is also still uncertainty in the location of highest amounts, with recent rapid-refresh guidance taking another slight shift to the south and bringing the highest amounts through Bismarck. Because of this uncertainty, we remain comfortable with a high- end Winter Weather Advisory for now. But observed and modeled trends will need to be monitored closely through the night.

DISCUSSION

Issued at 240 PM CST Mon Nov 24 2025

Currently the state is under zonal flow, and switching to southwest flow. A shortwave trough is starting to dig through Montana, this will be our snow producer later. Another low pressure area sits in the Central Plains. At the surface higher pressure is being forced out of the northern part of the state, with pressure falling elsewhere. There is currently a surface trough located in western North Dakota, moving east. With it is a light rain/snow/ice pellet mix.

A Winter Weather Advisory has been issued for almost all of the state, except the far northeast, this evening through Tuesday night. With the 12z and 15z models, there has been a slight southern shift in the northwest to southeastern track. This combined with the strong winds, led to the decision to go CWA wide Advisory. In this northwest to southeast track, there is a potential for up to 9 inches of snow, otherwise its a wide path of 4 to 6 inches. The NBM might have too high of snow totals and probabilities, but the chance of at least 4 inches is 50 to 80 percent in that track. For greater than 6 it drops to around 50 percent, but again the NBM might be too aggressive, but so is every other model. We are leaning more on the lower end of those probabilities because the system seems very progressive over the Dakotas. Once it gets to Minnesota, the upper low looks to wrap up and deepen which will slow down and produce more snow. When and if we see the snow band setup, and we are confident in a swath of at least 6 inches, when we will upgrade those counties to a Warning.

This is mostly a synoptic driven system with an open shortwave deepening and wrapping up to the east of the Dakotas. Across all models the Q vectors are very strongly negative across the northwest, central, and southeastern portions of the state. The models differ where the vectors turn positive again, where this happens, the snow totals will drop significantly (in the positive values). Some models have that line near the Missouri River, others have further into the southwest. Lapse rates with this system are very healthy with values around 8 degrees C per km. The surface low should be coupled with the 700mb low, both moving through southwest and south central North Dakota. There will also be some Frontogenesis forcing with this system too. There is some model disagreement in the location of it, but the consensus seems to be around the Missouri River or south. This mostly lines up with the swath of higher snow totals.

The pressure gradient force on the backside of the low is going to be very strong. Creating strong northwest winds kicking up tonight through Tuesday. The pressure bubble is also very strong, but we are actually on the northern end of it. The majority of the strong pressure bubble will stay in South Dakota. For this reason we do not have any wind headlines out yet, just in South Dakota. If winds start to increase to a High Wind Warning level (likely in the southwest), then that will be issued too. Overall it will for sure snow across most of North Dakota, we are just less confident in amounts and exact location for the highest amounts at this time.

After this system fully moves out Wednesday, temperatures will be well below average in the 20s for highs. Low temperatures will be in the single digits above zero this week and below zero this weekend. Another front and weak wave could impact the Northern Plains this coming weekend, but there is a lot of uncertainty with timing and location.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 129 AM CST Tue Nov 25 2025

Winter weather disturbance will bring widespread aviation impacts through the 06Z period. Snow will continue to expand over all terminals early this morning, before it is expected to end from west to east later this Tuesday morning and afternoon. IFR to LIFR visibility can be expected with the falling snow. Ceilings are also expected to lower to MVFR/IFR levels through tonight, with improvement from the west Tuesday afternoon. Winds will become north to northwest and strengthen this morning and into the day Tuesday, with sustained speeds around 20-25 kts and gusts as high as 35 kts. Winds will then taper off through Tuesday afternoon and evening.

BIS WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until midnight CST /11 PM MST/ tonight for NDZ001>003-009>013-017>023-025-031>037-040>048-050-051. Winter Weather Advisory until noon CST today for NDZ004-005.