textproduct: Bismarck

KEY MESSAGES

- Well below average temperatures statewide and dangerous wind chills north and east continue through Sunday morning. - Temperatures warm to above average through the first half of next week, then trend colder late in the workweek.

- A strong low pressure system could bring mixed precipitation and strong winds Wednesday and Thursday.

UPDATE

Issued at 846 AM CST Sat Dec 13 2025

Other than potentially a few flurries, snow has ended in the southwest. Therefore, allowed the Winter Weather Advisory to expire on time. Otherwise, the forecast remains on track.

UPDATE Issued at 556 AM CST Sat Dec 13 2025

For the most part, it looks like most of the accumulating snow has ended over southwest ND. However, webcams indicate snow is still falling and roads are snow covered. Will keep the Winter Weather Advisory going with the expiration time at 8 AM MST. No changes for the ongoing Cold Weather Advisory either. Updated text products will be transmitted shortly.

DISCUSSION

Issued at 400 AM CST Sat Dec 13 2025

Latest WV imagery shows an upper level ridge situated over the eastern Pacific with a closed upper low over southern Ontario. A shortwave trough propagating through the northwest upper flow over the Northern Plains is tracking across southwest ND.

Latest radar loop shows a band of moderate to heavy snow over far southwest ND, along and south of Highway 12 from Baker MT, to Bowman, to Hettinger. This band was dropping slowly south. To the north and east of this, light to at times moderate snow extended as far north as Sidney MT and Watford City, and as far east as Hazen, Bismarck Mandan and Linton. It will be interesting to hear what type of accumulations we end up with over the far southwest where the band of heavier snow has persisted the longest, given that the combination of the time the column to 600 mb was near or in the DGZ and temperatures were in the single digits, could probably support SLR values of 20 to 30 to 1. We'll see.

It's likely that most of the accumulating snow will end by 12Z, even in the far southwest, but with roads still snow covered will leave the winter weather advisory alone until after sunrise. Once light snow ends this morning, we begin a nice stretch of dry weather into early next week.

Farther to the north, our Cold Weather Advisory remains in effect. Current wind chills in the advisory are mostly 25 to 35 below zero. No plans other than continuing the advisory early this morning.

A 1041 MB surface high tracks southeast across the forecast area today, resulting in a cold day today across western and central North Dakota. Highs will range from the single digits below zero north and east, to the single digits above zero southwest.

Tonight, a progressive westerly flow off the Pacific will push the Arctic high off to our southeast. Initially this evening, the forecast area, especially central ND will be in a favorable position for cold temperatures. However, strong warm advection pushes east across the forecast area through the night, with surface temperatures already forecast to be on the rise in western ND this evening, and with temperatures rising over central ND late evening and through the overnight. Overall, it will still be cold with low temperatures generally in the 10 to 20 below range. Wind chills are not expected to be a cold as tonight, but wind chills of 30 to 35 below are forecast along and north of the Highway 2 corridor and also in far eastern portions of the forecast area, including the James River Valley. No plans to update the advisory at this time, but there may be a few tweaks on the day shift.

With the warm advection a southerly return flow will develop over western ND late this evening, and spreading east across the forecast area through the day Sunday. Patchy blowing and drifting snow are possible where there is remaining loose snow. Highs Sunday will range from the 20s over central ND to the 30s west.

Looking ahead to next week, mild temperatures continue through mid-week. NBM ensemble temperature spreads remain pretty low through this timeframe so confidence is high in the mild temperatures. This is due to a strong westerly flow off the Pacific and across the rockies, with westerly chinook winds encroaching into the state. Tuesday looks to be the warmest day of the week with 40 degree readings forecast across the entire forecast area. We cool a little Wednesday behind a clipper that tracks across southern Canada. The next clipper type system comes off the Pacific and tracks along the International Border as it traverses the Rockies. Then as it moves into the plains it drops southeast through the state Wednesday night. Each of these clipper systems will bring some winds. The first should remain mostly dry as we are south of the low, in the warm/dry sector. The second is a stronger wave and will bring a better chance of precipitation with it, a mixed bag of precip on Wednesday, ahead of the low, then snow on the back side of the low Wednesday night into Thursday, as a chunk of Arctic air gets pulled over the state behind the exiting low. If the first system looks a little windy, the second definitely looks windy. It's still a ways out, but with the current chances for precipitation (30 to 60 percent) given by the NBM, the possibility of mixed precipitation given the warm temperatures initially, and the possibility of strong winds and much colder temperatures on the back side of this system, we could see some impactful weather in the Wednesday-Thursday timeframe. The latest ECMWF EFI is not showing anything overly impressive, but there is a signal for stronger winds over western ND Wednesday and eastern ND Thursday.

Temperature wise, we transition from a low ensemble spread early in the work week to a moderately high ensemble spread late in the work week. There is definitely a noticeable drop in temperatures after Wednesday. The extent of the drop is the main question, given the large ensemble spread. With the continuation of a progressive upper flow, whatever does end up happening, probably won't last too long.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 556 AM CST Sat Dec 13 2025

VFR conditions are expected across the forecast area through much of the 12Z TAF period. The exception being MVFR visibilities and an occasional MVFR ceiling in light snow that will continue to taper from north to south over southwest and far south central ND this morning. Once conditions improve here, VFR conditions are expected through the rest of the TAF period. In general, a modest northwest flow today diminishes and shifts southerly from west to east late afternoon through this evening, with southerly winds increasing after midnight.

BIS WATCHES/WARNINGS/ADVISORIES

Cold Weather Advisory until 9 AM CST Sunday for NDZ001>005- 009>013-021>023-025-036-037.