textproduct: Bismarck

KEY MESSAGES

- There is a 10 to 30 percent chance for a mix of light freezing rain and snow along and and north of a line from Minot to Jamestown through the mid morning. - Warmer today, then a large spread in temperatures from northeast (colder) to southwest (warmer) mid to late week.

- Medium to high chances for snow mainly across central and eastern North Dakota Tuesday night into Wednesday.

UPDATE

Issued at 600 AM CST Tue Dec 30 2025

Areas of weak and pockets of moderate reflectivity linger over north central North Dakota into the northern James River Valley. These radar signatures have diminished rapidly over the past two hours conditions above the 850mb layer have dried out significantly. That being said, another push of moisture is moving in across the north central at this time. Evidence for precipitation reaching the ground is mainly restricted to this area, and much of this has fallen as a wintry mix of freezing rain and snow due to the erosion of the 950 to 850 mb warm nose aloft. QPF reports from automated weather stations have broadly been from a trace to 0.01" along a line from Minot down through Jamestown. In the Turtle Mountains Area, slightly higher amounts up to 0.05" were observed. Here, analysis reveals a short lived band of enhanced precpitation developed where moderate FG forcing and Q-G convergence overlapped. All remaining precpitation is expected to move east out of the forecast area by the mid morning. With this update, have made some slight adjustments to PoPs to account for a slightly slower erosion of its western flank, and have blended in the latest satellite and model trends into the sky cover. Otherwise, the forecast remains on track at this time.

DISCUSSION

Issued at 345 AM CST Tue Dec 30 2025

Northwesterly flow is found over the northern Plains this morning. A shortwave and associate surface low system has developed over the southern Canadian Prairies, and is expected to cut across northeastern North Dakota on its way to the Great Lakes through the day today. A warm front and trailing surface trough associated with this low pressure system is currently passing from west to east this morning. With the ongoing WAA, scattered precpitation has developed across northwestern and central North Dakota. A somewhat shallow 950 to 850 mb nose is evident on BUFKIT model soundings across this area as the WAA continues, which will allow for periods of light freezing rain mixed with snow through the mid morning, mainly behind the aforementioned warm front. With drier air wrapping around the low at the 850mb layer, and the relatively quick moving nature of this system, the period during which precpitation falls is fairly brief, and thus overall accumulations are expected to remain light. That being said, there is an axis of low to medium chances for a glaze of ice from the Turtle Mountains area to Fargo through the mid morning. The best potential for such remains over the Turtle Mountain area, as the residence time of precpitation is highest here. We have opted to issue an SPS across much of northwestern and portions of central North Dakota due to the very light nature of these accumulations. Otherwise, low temperatures are expected to range from the mid single digits across the James River Valley north through the Turtle Mountains area, up to the upper teens in the southwest.

Mainly dry conditions are then expected through this afternoon, though CAMs continue to hint at limited banded precpitation potential across eastern North Dakota at this time. Depending on where this actually develops, portions of the James River Valley could see a brief period of light rain this afternoon, though confidence in this is very low. Otherwise, for today, breezy northwest winds sustained up to 25 MPH and gusting as high as 35 MPH are expected this afternoon as cold front and thus moderate CAA digs in from the north this afternoon and evening. A 40kt 850mb jet will be lingering across the east at this time, though the timing is such that fully mixing these winds down seems unlikely. High temperatures this afternoon are forecast around freezing in the Turtle Mountains area, up to the upper 30s and lower 40s in the southwest.

With the cold front passing through the region this afternoon through tonight, a fairly stark NW-SW orientated baroclinic zone is expected to set up somewhere across the state. A clipper system is then progged to develop along this baroclinic, promoting medium to high chances (40 to 80 percent) for precpitation early tonight through Wednesday morning. While much of this is anticipated to fall as accumulating snow, brief periods of a wintry mix of light freezing rain and snow is possible along the southwestern edge of the baroclinic zone. No ice accumulation is currently anticipated. Overall snow accumulations remain in line with the past few forecast cycles, with the axis of highest amounts found in the Turtle Mountains area down to Fargo. Broadly speaking, less than an inch expected in the northwest and south central, and an inch or two north central into the northern James River Valley. Two things to keep in mind with these amounts are 1) The axis of highest accumulation is highly dependent on the location of the baroclinic zone which, while confidence is increasing in a slightly more eastern placement, can still chance and 2) there has been a pervasive banded snow signal for the past few days as moderate to high FG forcing and decent lapse rates are expected. Locally higher amounts of snow should be anticipated where ever these bands set up, and there remains a good amount of disagreement between individual ensemble and HREF members as to where this would be. The majority of members (approximately 67%) favor this to be along the aforementioned axis of highest snowfall from the Turtle Mountains down through Fargo, though a minority cluster (approximately 33%) also exists and instead favors this banded snow setting up from a line from Minot down through Jamestown.

Looking ahead Wednesday through the end of the workweek, cyclonic flow is expected to develop over the forecast area as a Hudson Bay Low retrogrades into place. A strong temperatures gradient lingers through Wednesday the backside of the cold front, with highs from around zero in the Turtle Mountains are up to the mid 30s in the southwest and lows from 10 below north central to the lower 20s above southwest overnight. Longer term models continue to be somewhat discordant during this period as they struggle to resolve its interaction with the remnants of the clipper. The majority of ensemble members (approximately 75%) continue to favor near to slightly above normal temperatures through the weekend as the two lows merge and deepens over the bay. Notably, a minority cluster (approximately 25% membership) instead favors much cooler temperatures through this period as these lows orbit and displace each other through the weekend. Otherwise, there is no strong signal for precpitation through Saturday though the odd shortwave transient shortwave traversing the cyclonic flow could allow for low to medium chances for light precpitation basically any day. By Sunday into early next week, the ensemble becomes even more discordant as the the displacement of the Hudson Bay Low could allow for the breakdown of the cyclonic flow pattern. When and how the synoptic flow evolves during this timeframe remains uncertain, though a pattern shift some time during this period seems like a decent bet.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 600 AM CST Tue Dec 30 2025

VFR ceilings and visibility are found at all terminals to begin the 12Z TAF period. Isolated pockets of a wintry mix of freezing rain and snow can be found over portions of north central North Dakota into the northern James River Valley this morning, though confidence is too low to include mentions of such at any given TAF site at this time. All precpitation is expected to diminish and move off to the east through the mid morning. This afternoon through this evening, MVFR to IFR ceilings will drop south out of Canada into the northern and south central North Dakota. Tonight, accumulating snowfall is expected to come out of this stratus deck, with the highest confidence over the Turtle Mountains. Around a trace to 1 inch of snow is broadly expected, though there is some potential for locally heavier amounts where banded snow does develop. With this update, have added PROB30 groups for light SN at KMOT and KJMS. Confidence remains too low to include mentions of such at any other terminal. Snow is expected to diminish and move off to the east through Wednesday morning and the end of the TAF period.

Gusty northwest winds are expected this morning as a low level jet develops, with the strongest found over south central North Dakota. Sustained speeds up to 25 knots and gusts up to 35 knots are expected. With this jet, wind shear is expected at KXWA, KMOT, KBIS, and KJMS through the mid morning. Winds are expected to diminish through the late afternoon and evening, turning westerly through the evening and early overnight, then northeasterly as a cold fron passes through the forecast area early Wednesday morning through the end of the TAF period.

BIS WATCHES/WARNINGS/ADVISORIES

None.