textproduct: Bismarck

KEY MESSAGES

- Patchy to areas of fog later tonight into Saturday morning.

- Well above average temperatures through the weekend (normal around 50 to 55 degrees).

- Precipitation chances return Sunday night and continue into Monday night/Tuesday. Greatest chances central into eastern North Dakota Monday (~40-60 percent).

- Near average temperatures for at least the first half of the upcoming work week.

UPDATE

Issued at 954 PM CDT Fri Oct 24 2025

Limited updates needed late this evening. High clouds remain across much of the state, however mostly clear to partly cloudy skies are expected tonight. Hi-res models continue to show fog possible tonight into Saturday morning, especially in the James River Valley. Thus maintained fog mention. Overall the forecast remains on track.

UPDATE Issued at 640 PM CDT Fri Oct 24 2025

Forecast overall remains on track. Abundant high clouds are moving in across the west and into some central portions. Hi-res model guidance showing increasing confidence in areas of fog tonight into Saturday morning, mainly in the James River Valley. Have increased fog mention to areas in these higher confidence regions.

DISCUSSION

Issued at 157 PM CDT Fri Oct 24 2025

Current surface analysis places broad high pressure over the midwest into western Ontario, with modest south to southwesterly flow over our area. Upper level analysis places split flow over the western CONUS with a low along the Colorado/New Mexico border and modest ridge over central/eastern Montana. Compact low slides down the face of the ridge over the northern Red River Valley, but its impact on our area is quite limited, only producing some clouds over parts of the James River Valley.

For tonight, upper low scampers along its way to the southeast with aforementioned upper ridge tracking east over our area. This will keep quiet conditions over our area. Only concern at this point it the potential for some fog over eastern/northern portions of our area. Guidance has been quite consistent with advertising its potential so will mention the possibility for patchy fog at this time.

Saturday looks to be a very warm day for this time of year, with highs pushing into the 60s (possibly a few 70s west), which is about 10 to 20 degrees above average. The only pesky part with the day may be the south-southeasterly winds increasing to around 15 to 20 mph over most locations.

Changes come Sunday as upper ridge pushes east and very broad trough to the west slides east, which then starts to close off over the Alberta/Saskatchewan border. Temperatures remain seasonably mild for one more day, but winds will be on the increase (especially over central NoDak/James River Valley) before the cooler air works in. Low to medium (20 to 40 percent) rain shower chances develop overnight Sunday.

Monday will see temperatures closer to normal with low rain shower chances west (~20 to 30 percent), greater chances over central North Dakota into the James River Valley (~40 to 60 percent) as a variety of waves circulate around the gradually eastward tracking aforementioned upper low. Rain shower chances gradually taper over the west overnight Monday, with chances gradually tapering elsewhere from west to east Tuesday.

A momentary quiet period expected for Wednesday before low chances for precipitation return Wednesday night through the end of the work week as some weak waves move through. Temperatures look to to linger near normal, though towards the end of the work week NBM probabilities are showing a little more of a spread.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 640 PM CDT Fri Oct 24 2025

VFR conditions with some high clouds will be found through this evening. Patchy to areas of fog could be found tonight and bring IFR to perhaps LIFR conditions. Confidence was only high enough to place fog mention in the KJMS TAF at this time as the James River Valley currently has the the highest probability of seeing fog. After fog diminishes later Saturday morning, mainly VFR conditions are expected for most sites. A breezy southerly wind may also develop Saturday afternoon.

BIS WATCHES/WARNINGS/ADVISORIES

None.