textproduct: Bismarck

KEY MESSAGES

- Widespread dense fog is possible across much of western and central North Dakota overnight through Thanksgiving morning. Areas of fog are then possible again Friday morning.

- There are medium to high chances (60 to 80 percent) for accumulating snowfall Friday and Friday night across portions of western and south central North Dakota.

- Well below average temperatures are favored for this coming weekend and into early next week. Wind chill temperatures as low as 25 below zero will be possible both Saturday night and Sunday night.

DISCUSSION

Issued at 400 AM CST Thu Nov 27 2025

Northwesterly flow can be found across the northern Plains this morning. At the surface, high pressure continues to bleed into northwestern North Dakota this morning out of the southern Canadian Prairies. With the resulting calm winds, and with plenty of snow pack across much of northern and central North Dakota, areas of fog and low stratus lingers across the forecast area. Visibilities across portions of northwestern and south central North Dakota, where winds are weakest, have dropped as low as 1/4 SM. With high clouds pushing in the southwest, fog has struggled to develop outside of shallow valleys. A Dense Fog Advisory remains in effect through the mid morning across portions of northwestern and central North Dakota. Fog is generally anticipated to lift through the late morning, though may linger over portions of the northwest and north central through the early afternoon. Otherwise, isolated flurries are also possible across portion the James River Valley this morning. Low temperatures are broadly in the positive single digits under the stratus deck. Where skies remain somewhat clear, mainly in the southwest and far south central, lows in just below zero are expected. Highs temperatures this afternoon are broadly expected to be from the mid to upper 20s in the far southwest, to the upper teens to lower 20s elsewhere. Areas of fog are again possible across the northwest and central this evening and overnight across northwestern and portions of central North Dakota, though are anticipated to start lifting by the early to mid morning Friday.

Late tonight through early Friday, an upper level low in the Pacific Northwest is expected to merge into the general northwestern Flow over Idaho/western Montana. The resulting shortwave and associated surface low pressure system is expected to induce widespread snowfall across the region Friday afternoon through the weekend. The trajectory of this system is such that the bulk of the this snowfall is expected to fall to the south and east of North Dakota, though wintry precipitation developing along and behind a surface trough/cold front is progged to clip portions of the west and south central Friday afternoon through early Saturday. An interrogation of BUFKIT model soundings across the affected area during this period reveal a somewhat shallow saturated DGZ and unimpressive mid level lapse rates around 6 C/KM. Considering this and the the fairly progressive nature of this system, overall snowfall totals are forecast to be limited compared to some of our neighbors. That being said, there is some decent agreement between ensemble model families at some limited banding potential across portions of the far southwest into the far south central Friday afternoon and evening as weak 700-850mb FG forcing slides along the ND/SD border, becoming briefly aligned with moderate to strong Q vector convergence as it does so. If this scenario comes to pass, some moderate snowfall rates would be anticipated during this period, and thus enhancing the overall snowfall accumulation. As of current forecast cycle, the NBM 5.0 calibrated probability to exceed 2 inches of snowfall through Saturday is from 50 to 80 percent south and west of the Missouri River, and over an area along and south of I94 in south central North Dakota. Notably, this area has sunk further to the south and west over the past few forecast cycles as the NBM catches up with its constituent ensemble families. Similarly, the band of low to medium potential for 4 inches or more of snow has sunk further south, and remain highest of the far southwest into far south central North Dakota. If and where the limited banding potential does set up Friday afternoon and evening, a few locations in this same area could approach or even exceed 6 inches of snow overall, though this potential (10 to 30 percent) may continue to be displaced further south into South Dakota over the next few model runs. We will continue to evaluate this system over the next few model runs.

After highs linger in the upper teens to mid 20s on Friday, a much colder airmass is expected to settle over the region through the weekend, reinforced by near northerly flow aloft. Seasonably cold high temperatures broadly in the teens on Saturday then drop even lower on Sunday, from the mid single digits northwest to lower teens south. With this, overnight low temperatures Saturday night and Sunday night are expected to broadly sink in the single digits below zero. While winds remains relatively light during this period, they will be sufficient to drive wind chills into the teens to lower 20s below zero both nights. The ensemble becomes increasingly discordant beyond this point, though broadly speaking the surge of arctic air is expected to cease as northwesterly flow is reestablished. A weak shortwave sliding around a Hudson Bay Low sometime Tuesday through Wednesday could invite another dusting over snow over portions of the forecast area during this period, though confidence in this remains somewhat shaky due to how shallow this deviation is. Looking even further ahead, climate analogues continue lean toward below normal temperatures through the first week of December.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 400 AM CST Thu Nov 27 2025

Low stratus and fog can be be found across much of western and central North Dakota at the start of the 06Z TAF period. IFR to LIFR ceilings and visibility are expected at all terminals at all terminals through mid to late Thursday morning, with conditions beginning to improve by the early afternoon. Another round of low stratus and fog will be possible across western and portions of central North Dakota late Thursday evening through the end of the TAF period, though confidence remains too low to include at any given terminal with this update. Otherwise, light north to northwest winds tonight through Thursday morning will start to turn south southeasterly Thursday afternoon and evening.

BIS WATCHES/WARNINGS/ADVISORIES

Dense Fog Advisory until 10 AM CST /9 AM MST/ this morning for NDZ001>003-009>011-017>022-034>036-046-047-050.