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KEY MESSAGES

- Lows from 5 to 15 below with wind chills as low as 20 to 30 below this morning.

- Low chance for light, non-accumulating wintry precipitation late this evening and overnight mainly north central into the northern James River Valley.

- Warmer to start the workweek, with a large spread in temperatures from northeast to southwest for the mid to late week.

- A clipper system will bring low to medium chances for snow to mainly northwest and central North Dakota Tuesday night into Wednesday.

UPDATE

Issued at 635 AM CST Mon Dec 29 2025

Quick update to trim the western extent of the Cold Weather Advisory, mainly where wind chills have risen above criteria due to winds greatly diminishing and where overriding mid level clouds have helped moderate air temperatures.

UPDATE Issued at 545 AM CST Mon Dec 29 2025

Quiet weather is found across the forecast area at this time. Wind chills across north central North Dakota into the northern James River Valley are are as low as 25 to 30 below zero at this time, though will continue improve through the mid morning. With this update, have blended in the latest satellite and model trends into the cloud cover. Otherwise, the forecast remains on track at this time.

DISCUSSION

Issued at 330 AM CST Mon Dec 29 2025

Flow over the northern Plains is turning increasingly northwesterly this morning. With high pressure building in at the surface over the forecast area, clearing skies and slowly diminishing winds are expected through the early morning. With this, lows this morning are from around 15 below across the International Border, up to around 5 below in the southern James River Valley. Winds chills this morning across the north central into the northern James River Valley are similarly cold, as low as 30 below zero across this area. A Cold Weather Advisory is thus in effect through the mid morning, when sunrise and weakening winds will help warm things up. It's looking likely that an even earlier cancellation will be possible depending on how quickly the winds diminish between now and then. Dry conditions are then expected through the afternoon today, though cloud cover will increase from northwest to southeast during this period.

A transient northern stream wave will pass through the southern Canadian Prairies this afternoon and evening, with an associated clipper system expected to drag a warm front across the region during this period. Highs are thus forecast to be warmer today, from the lower to mid teens in the James River Valley up through the Turtle Mountains area, to the lower 30s in the southwest. With modest low to mid level WAA thus moving from west to east across the forecast area this evening and overnight, portions of the north will have low chances for precpitation. An interrogation of BUFKIT model soundings during this period reveals that the column will struggle to fully saturate at times throughout this period, which is anticipated to harshly limit the amount of precpitation that actually reaches the ground. That being said, the ongoing WAA could allow a shallow 900-850mb warm nose to develop within the saturated column, which could allow for brief periods of light freezing rain behind the front. Ahead of the front, light snow would be anticipated. Our current expectations is that accumulations of ice or snow would be very limited to non- existent. Otherwise, with the warm front passing through the region, a non diurnal temperature trend is expected, briefly cooling afternoon sunrise today through the early evening, before warming overnight through Tuesday afternoon. With this, low temperatures tonight are forecast from the mid to upper single digits in the James River Valley up through the Turtle Mountains area, to the lower 20s in the southwest.

Mainly dry conditions are then expected late Tuesday morning through Tuesday afternoon, before a backdoor cold front crosses the International Border south through the forecast area Tuesday evening and overnight through Wednesday. With this being a relatively quick moving front, a fairly tight baroclinic zone is expected to develop across the forecast area. With this better forcing, and with a much more saturated airmass over the northern Plains, medium to high chances (40 to 70 percent) for precipitation somewhere in North Dakota. Where exactly this precpitation develops is going to be very dependent on where the aforementioned baroclinic sets up. The ensemble remains fairly discordant on its placement at this time, evident with a 15+ degree 25-75th temperatures spread on Day 3, though cluster analysis reveals two scenarios. A slight majority cluster (approximately 55 percent of model members) favors the axis of precpitation to be a draped from Minot down through Jamestown, while the minority cluster (45 percent membership) is displaced further to the east, from the Turtle Mountains area down through Fargo. In either scenario, snow accumulation is expected to be fairly light due to the fast-moving nature of this system, with the NBM calibrated probability of more than 2 inches of snowfall only from 20 to 50 percent. That being said, there is some potential for higher amounts due to banded snow during this period, as global models are advertising decent lapse rates and moderate 925-850mb FG during this period. Where these potential snow bands setup remains similarly up in the air at this time, so we'll continue to evaluate this system as we head into the early week.

Uncertainty continues to build beyond this point as the ensemble struggles to resolve the relative strengthen and placement of a Hudson Bay low through the end of the weekend. Overall, a northwesterly flow pattern over the forecast area seems to be favored at this time which, while no strong signal is currently evident, could allow for periods of light precpitation. Cluster analysis reveals that the majority of model members (80 percent) favor near to slightly above normal temperatures through this weekend, though a strong NE to SW gradient can be anticipated. Looking ahead, this falls well in line with the latest CPC days 6-10 climate outlook for the first week of January, which highlights North Dakota as slightly favored for above normal temperatures, and for above normal precpitation across the north. Notably, a cooler solution also exists with below normal highs, though this is a underdispersed cluster of mainly GEPs sub members.

BIS WATCHES/WARNINGS/ADVISORIES

Cold Weather Advisory until 9 AM CST this morning for NDZ003>005-011>013-022-023-025-036-037.

BIS WATCHES/WARNINGS/ADVISORIES

Cold Weather Advisory until 9 AM CST this morning for NDZ005- 013-023-025-037.