textproduct: Bismarck

KEY MESSAGES

- Dry weather and near to above normal temperatures are expected through the work week, possibly lasting into Saturday.

- Much colder temperatures with medium chances for precipitation arrive for the second half of the weekend into early next week.

UPDATE

Issued at 1152 AM CDT Tue Oct 6 2026

Current forecast remains on track. No updates needed at this time.

UPDATE Issued at 929 AM CDT Tue Oct 6 2026

A few high clouds streaming by this morning, otherwise quiet weather is in store today. Made a few adjustments to sky cover based on latest satellite imagery, otherwise no changes needed to the going forecast.

UPDATE Issued at 643 AM CDT Tue Oct 6 2026

The early morning forecast remains in good shape. Current conditions and trends were blended in for this update. Despite some higher clouds, early morning temperatures have fallen as low as the mid 30s on an isolated basis across low-lying areas of western North Dakota.

DISCUSSION

Issued at 357 AM CDT Tue Oct 6 2026

A northwest upper flow pattern is forecast to persist over the Northern Plains today through Thursday. A progressive shortwave moving through Manitoba and Ontario will push a cooler air mass into the state from north to south later today through tonight. High temperatures today are forecast to range from the upper 60s north to upper 70s south. Surface high pressure building off the Northern Rockies behind a warm front exiting the Red River Valley this morning will produce northwest winds around 15 to 20 mph this afternoon, strongest in the far southwest where RH as low as 20 percent could yield near-critical fire weather conditions. Surface winds relax tonight as the high pressure continues to build eastward, but mid to high clouds may prevent overnight temperatures from tanking to near-freezing. CAMs show that a band of lower to mid level frontogenesis may produce some light rain showers from north central into northeast North Dakota late tonight into Wednesday morning, but a dry low level layer of air will likely prevent measurable precipitation at the surface.

Wednesday will be cooler, but still seasonable with highs in the lower 60s to lower 70s. A secondary push of cooler and drier air will reorient the surface ridge axis from central Alberta to southwest North Dakota, resulting in a breezy afternoon for the eastern half of the state. The broad surface ridge then focuses more squarely over the region Wednesday night, but mid to high clouds could once again prevent temperatures from falling below freezing. It is likely to be cooler Wednesday night than tonight though, with lows mostly in the mid 30s to lower 40s. Thursday looks to be less breezy with a similar high temperature forecast in the lower 60s to lower 70s as the broad surface ridge lingers over the region.

A potent trough digging into British Columbia and the Pacific Northwest on Friday will force low amplitude ridging over the Northern Plains, quickly transitioning to southwest flow aloft as the longwave trough continues deepening along the Pacific coast. Ensemble guidance is in good agreement on the phasing of synoptic scale features through Friday night, when the heart of the low level thermal ridge is forecast to pass through the region. Warm air advection commences in time to bring Friday's high temperature forecast near 80 in far southwest North Dakota, with 70s favored for most other parts of the forecast area. There is high confidence that a much colder air mass will enter the region sometime over the weekend, but the timing of the cold frontal passage through central North Dakota ranges from as early as during the day Saturday (heavily favored by the GEFS) to as late as during the day Sunday (an ensemble cluster with 37 percent of the total membership). This lends to large spreads in the NBM high temperature distribution on Saturday, with the 50th percentile maintaining around 60 degrees northwest to near 80 southeast. That drastically changes on Sunday, when there is smaller ensemble spread and higher confidence in daytime maximum temperatures only in the 40s west and north to 50s south central and southeast. High temperatures similar to these remain in the forecast through Monday, with only a slight warming trend thereafter. There will also be a potential for widespread sub- freezing temperatures both Sunday and Monday nights.

The NBM increases precipitation chances to around 30 to 60 percent across much of the area from late Saturday through Sunday and into Monday. This lines up well with raw global ensemble QPF probabilities. Both sets of guidance favor light QPF, with only low to medium chances for exceeding 0.25" over any given 24-hour period. This corresponds well to the evident uncertainty in the evolution of the western CONUS trough and what downstream forcing mechanisms could line up to produce appreciable precipitation. A couple ensemble clusters do hint at a northern stream shortwave cutting off from the western trough, and this outcome is likely the most contributive to the aforementioned 30 to 60 percent PoPs Sunday into Monday. NBM low temperatures in the lower to mid 30s Sunday night has allowed a rain/snow mix to enter the forecast, and that actually corresponds well to low NBM probabilities for measurable snow that are no greater than 20 percent in the southwest, and no greater than 10 percent elsewhere.

Two ensemble clusters constituting 60 percent of the total membership keep the base of the longwave trough over the Desert Southwest through Tuesday, and a singular cluster with 40 percent membership favors the trough kicking into the Northern and Central Plains around mid week, akin to the 00Z deterministic GFS and ECMWF. This outcome could produce a system with a higher precipitation ceiling, but only for some parts of the region and with very high probabilities for only rain as a precipitation type.

BIS WATCHES/WARNINGS/ADVISORIES

None.