textproduct: Bismarck

KEY MESSAGES

- Snow will gradually diminish over south central North Dakota and the James River Valley this evening. Gusty north-northwest winds will continue to cause areas of blowing and drifting snow through the evening.

- There are medium chances for light accumulating snowfall Friday and Saturday across parts of the Northern Plains, which may impact travel.

- Well below normal temperatures are favored after Thanksgiving and into early next week. Wind chill temperatures as low as 20 below zero will be possible Sunday night.

UPDATE

Issued at 619 PM CST Tue Nov 25 2025

The Winter Weather Advisory has been cancelled. Conditions have greatly improved outside of the southern James River Valley, where a Winter Storm Warning remains in effect. Still could see patchy blowing and drifting snow through the evening, and roads are likely to remain or become very slick.

The main concern for the short term period is the potential for fog development later tonight. Stratus is beginning to retreat from western North Dakota where a surface ridge is forecast to build in through tonight. This could promote a favorable setup for fog formation with light winds and differential cooling along the edge of the stratus, and surface dewpoint depressions are already near zero. Some models maintain fog, or perhaps very low clouds, through the day tomorrow and then show potential for a widespread dense fog event from northwest to south central North Dakota Wednesday night.

UPDATE Issued at 348 PM CST Tue Nov 25 2025

Canceled the Winter Weather Advisory for the northern tier of counties now that the snow has fully left the area. Blowing snow is not a major concern with how wet it has been.

DISCUSSION

Issued at 245 PM CST Tue Nov 25 2025

Currently the upper level low is maturing and deepening over northeastern South Dakota. There is an obvious dry slot wrapping in over southwest Minnesota, with a warm front moving through southern Minnesota. The surface low is almost in the same spot, so the low pressure system should be stacked at this point and continue to create high snowfall rates and amounts.

Here in western and central North Dakota, the snow has ended across the west and north central. Fog has now formed in the west and north as the wet snow starts to evaporate. In the south central a band of snow has formed in the diffluent flow as the low pulls away. It is currently moving east through Bismarck/Mandan. We had to update the NBM forecast to account for this since it had no snow there anymore. Snow is also starting to let up in the southeast. We have not received any recent reports, but it looks like the upgrade to a warning has worked out. Overall winds underperformed since the surface low was further south into South Dakota than forecasted. Still, blowing snow is possible through this evening, especially in the southeast. High pressure has formed in Montana under northwest flow and will push into the state overnight. With this, overnight lows will be in the single digits to teens.

The rest of this week will be much colder, about 10 degrees below average highs (mid 30s). Strong northwest flow will dominate. Friday another system looks to impact the Northern Plains. A shortwave will dig through Montana, producing a Northern Rockies low. Confidence is increasing in this event as it has been in the models for a few days now. With this a few inches are possible but it should not be as much as the current storm. Timing as of now looks like Friday early afternoon through Saturday evening. This low will wrap even colder air down from Canada, cooling our highs down to the teens. Low temperatures will likely be in the negatives with wind chills even lower. We will continue to closely monitor this, especially with the holiday weekend travel.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 619 PM CST Tue Nov 25 2025

MVFR to IFR ceilings are forecast to slowly retreat eastward through the forecast period. Think that KJMS will maintain an MVFR ceiling through Wednesday afternoon. Parts of western North Dakota could see fog and or very low stratus develop along the back edge of the retreat MVFR/IFR cloud deck later tonight into Wednesday morning. Northwest winds will gradually diminish through tonight, becoming light and variable across the western half of the state on Wednesday.

BIS WATCHES/WARNINGS/ADVISORIES

Winter Storm Warning until midnight CST tonight for NDZ048-051.