textproduct: Bismarck

KEY MESSAGES

- Snow and freezing rain are expected across much of western and south central North Dakota through this afternoon, with periods of light snow, and patchy fog and freezing drizzle possible north central into the James River Valley.

- Well below average temperatures are expected through the upcoming weekend, with dangerous wind chills this evening through Sunday morning.

- Another round of accumulating snow could impact areas mainly south and west of Lake Sakakawea and the Missouri River Friday afternoon through Saturday morning.

UPDATE

Issued at 1012 AM CST Thu Dec 11 2025

Rain and freezing rain continues to be found mainly in southwestern portions of the state this morning. Meanwhile freezing drizzle and fog have developed in the north, central, and some eastern portions with some mid level drying. Current trends are forecast to continue through this morning. This wintry mix may then continue into this afternoon until an arctic cold front moves through from north to south and brings another round of light accumulating snow. Overall decided to let the current advisory continue as is. Did issue a Special Weather Statement to areas outside of the advisory that are experiencing fog and freezing drizzle this morning. This may need to be reissued for this afternoon, depending how long drizzle and fog lingers. Will monitor for a future update.

UPDATE Issued at 610 AM CST Thu Dec 11 2025

Periods of light rain continue over far southwest North Dakota with mixed precipitation (mainly freezing rain) form the west central into the far south central. North and eat of this area (north central into the JRV) light snow, patchy fog and freezing drizzle were reported. Expect this precipitation trend to continue through the morning and possibly into the early afternoon, before cooler temperatures dropping south from Canada, transition precipitation to all snow with the potential for some patch freezing drizzle. No significant chances were made to the going forecast. Updated text products will be transmitted shortly.

DISCUSSION

Issued at 400 AM CST Thu Dec 11 2025

Currently, satellite and radar show a narrow band of light snow along the Highway 83 corridor, pushing east through central ND. East of this band, the atmosphere has not saturated enough to produce precip at the surface. Behind the band, mainly along and west of the highway 83 corridor, we are saturated enough that we are seeing a mixed bag of snow and light freezing rain/freezing drizzle, until you get into the far southwest, where temperatures have climbed above freezing, and precipitation is rain.

For today, a band of heavier precipitation over northeast Montana will track across western and central ND, with the axis of the precip tracking from mainly west central ND into the far south central. This looks to be the focus for the heaviest accumulations of freezing rain. There are still uncertainties, mostly in precipitation amounts, but the general area seems pretty consistent. The HREF probability of a tenth of an inch or more of freezing rain is indicating medium probabilities (40-60 percent) over southern Grant and Much of Sioux counties, with low probabilities over eastern portions of Stark, Hettinger and Adams counties, as well as western Morton counties. If you look at probabilities of two tenths or more, they drop to less than 10 percent over Grant, Sioux and portions of Hettinger and Adams counties. Our NBM developmental (which is higher than the operational NBM) probabilities of a tenth of an inch or more of freezing rain are lower, generally 30 percent or less over western Grant and Sioux Counties and into far eastern Adams and Hettinger counties. Recent deterministic runs of the HRRR and RAP are similar in the placement and amounts. The NAMNest is also similar in placement, but is a high outlier, and the only CAM that is currently supporting Warning criteria ice accumulations. Outside of this area, but generally south and west of the Missouri River, lesser amounts of freezing rain can be expected, ranging from a light glaze to less than a tenth of an inch, which can still produce high impact hazardous travel. Will continue to monitor for a potential upgrade for a small area as we get closer to the 12-15Z timeframe, but for now will continue with our current Winter Weather Advisory, for light snow and up to two tenths of an inch or freezing rain. The far southwest, including Bowman and Slope counties, and portions of Golden Valley, Billings and Stark and possibly western portions of Hettinger and Adams counties will see mostly rain through this morning as temperatures here have already climbed above freezing.

The remainder of western and central ND, will likely see a mix of light snow/flurries and/or freezing drizzle this morning. Cold air begins to drop southeast into northwest ND this afternoon and continues propagating southeast through tonight. Precipitation this afternoon is expected to transition to either snow, or rain in the far southwest. There looks to be a period of light snow associated with the Arctic front, but until it passes, there could be a mixed bag of snow flurries and freezing drizzle in northern and eastern portions of the forecast areas, outside of the ongoing Winter Weather Advisory.

Later tonight we see the very cold Arctic air enter the state. It is likely that we will need Headlines for Cold air late tonight over northwest ND, and towards Friday morning for portions of central ND along, north and east of Lake Sakakawea and and into the northern James River Valley. The timing of arrival of the coldest air is such that it may be best to let the day shift take another look. It's possible that northern portions of the forecast area may be handled with more of a long term Advisory, through at least a portion of the weekend, but areas farther south would likely not reach this criteria. Being it's a late arrival tonight, it may be best to let the day shift take another look.

In addition to the Dangerous wind chills, patchy blowing and drifting snow is possible, mostly where we are able to see any light snow accumulations today. Otherwise, the warm temperatures and shot of freezing rain earlier this week have put a crust on much of the snow. The north central into the northern JRV would be the areas where some blowable snow still remains.

The next shot of snow from Friday afternoon through Saturday morning looks to remains mainly south and west of Lake Sakakawea and the Missouri River, with a moderate 40-70 percent chance of at least two inches mainly confined to far west central and southwest North Dakota. One thing to note with this snow, Bufkit soundings indicate that the entire column from the surface to around 600 mb is within the DGZ, which could yield some very high snow ratios. This could lead to some over achieving amounts of light fluffy snow.

After this bout of snow it looks like we may dry out through the remainder of the weekend and into early next week. The very cold wind chills will continue through Sunday morning, but look to retreat quickly on Sunday as we see strong ridging build over the region. We'll see if the current NBM temperatures hold, but we the NBM is already depicting highs into the low to mid 40s by Tuesday across much of western and central ND, along and west of the Highway 83 corridor. Generally following an Arctic airmass, the warmup can be slower to arrive than forecast. However, there is good agreement in the pattern shift. NBM ensemble spreads, especially over western ND, are really pretty low, adding confidence in a very noticeable warmup early next week.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 610 AM CST Thu Dec 11 2025

Widespread MVFR to IFR and at times LIFR ceilings and visibilities today across western and central North Dakota today and into this evening in areas of mixed precipitation and fog. The main area of freezing rain extends from west central into far south central ND, with mainly rain in the far southwest and a mix of light snow and patchy fog and freezing drizzle to the north and east of the area of freezing rain. Ceilings and visibilities are expected to slowly improve later this evening into the overnight hours as cold arctic air spills over the area, bringing strong northwest winds.

BIS WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 6 PM CST /5 PM MST/ this evening for NDZ009-010-017>021-031>035-040>046-050.