textproduct: Bismarck

KEY MESSAGES

- Near to above normal temperatures are favored through the middle of next week.

- Low chances for light rain and drizzle tonight through Sunday, then high chances for rain Sunday night through Monday night.

UPDATE

Issued at 525 AM CDT Fri Oct 30 2026

A Dense Fog Advisory has been issued for Bowman, Adams, and Slope Counties where widespread fog has been thick and persistent. Will stick with a Special Weather Statement in northwest and north central North Dakota where dense fog is not as widespread and has been observed to be variable outside of Divide and Burke Counties.

DISCUSSION

Issued at 417 AM CDT Fri Oct 30 2026

An upper level ridge axis extends from the Northern High Plains to the Gulf Coast early this morning while a closed upper low spins off the Pacific Northwest coast. A surface ridge axis is analyzed from Alberta to Wisconsin, cutting through the northern Red River Valley. This places western and central North Dakota under a mostly benign weather pattern, with the only impactful phenomenon being areas of dense fog that appear to be driven by radiation processes near the Canadian border in northwest and north central North Dakota, and by advection and orographic processes in the southwest corner of the state. The general expectation is that fog in the far north will dissipate either after sunrise or if low clouds move over, while fog in the southwest is more likely to lift into a low stratus deck. The daytime hours today will feature more clouds than sun, with high temperatures forecast to reach the mid 40s to mid 50s.

Mid level shortwave energy will begin to eject from the base of a western CONUS trough by tonight as underlying low level southeasterly flow maintains a broad warm air and moisture advection regime over the Northern Plains. High-resolution models show favorable conditions for thick stratus with periods of drizzle developing in southwest North Dakota tonight and gradually spreading north and eastward through Saturday afternoon. Should this occur, the NBM high temperature forecast on Saturday of lower 50s to lower 60s would likely be 5 to 10 degrees too warm, even with dewpoints rising into the mid 40s to mid 50s. A more well-defined mid level shortwave could bring light rain showers (as opposed to just drizzle) through the region Saturday night, but there is some uncertainty in the trajectory of the strongest forcing for ascent.

An overcast is likely to prevail over much of the forecast area through Sunday, with drizzle remaining possible as well. A continuation of warm air and moisture advection should lead to warmer high temperatures on Sunday, though again perhaps not quite as warm as the mid 50s to mid 60s advertised by the NBM. A deep western CONUS trough will begin to translate into the Plains Sunday night, inducing lee cyclogenesis that is favored to produce a Colorado low. Strong QG forcing over the Northern Plains brings high chances for rain (70 to 95 percent) across the forecast area Sunday night through Monday evening. Temperatures will remain warm enough for precipitation to only fall as rain (Sunday night lows in the upper 30s to upper 40s), and there may actually be enough MUCAPE to support a couple of elevated thunderstorms Sunday night into Monday morning. There has been a notable shift in ensemble data to both much higher QPF amounts/probabilities and the areal footprint thereof. The QPF gradient now increases from northwest to southeast, with medium chances for exceeding half an inch of rain and low chances for exceeding 1 inch. There is still uncertainty on the timing of the departure of the system, but recent ensemble guidance is trending toward lighter rain lasting into Tuesday, at least for the eastern half of the state.

The synoptic pattern for mid to late next week looks to be highly-amplified, but could feature predominant ridging over the central CONUS. This keeps the forecast dry after Tuesday, with seasonable temperatures of highs in the mid 40s to mid 50s and lows in the lower 20s to lower 30s.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 417 AM CDT Fri Oct 30 2026

Dense fog is possible across parts of western and central North Dakota this morning, but is unlikely to impact any TAF sites. There is a low chance that MVFR/IFR ceilings could move over KDIK this morning. VFR conditions are generally otherwise expected through this afternoon, although some pockets of MVFR ceilings cannot be ruled out. MVFR ceilings are then forecast to become more common later this evening through tonight. Expect easterly winds through the forecast period, with speeds around 5-10 kts this morning increasing to 10-15 kts this afternoon.

BIS WATCHES/WARNINGS/ADVISORIES

Dense Fog Advisory until 10 AM MDT this morning for NDZ040-043- 044.