textproduct: Bismarck

KEY MESSAGES

- Periods of light snow southwest this morning with some light accumulations in grassy areas far southwest.

- Medium to high chances for rain and snow southwest, south central and eastern North Dakota late this afternoon through tonight. Light snow accumulations are possible.

- Another system may bring low to medium chances for light rain and snow to northern portions of North Dakota Tuesday into Wednesday.

UPDATE

Issued at 629 AM CDT Mon Oct 26 2026

Made some minor adjustments to pops based on latest radar, and added some patchy fog in the south tonight into Tuesday morning. Otherwise no significant changes for the early morning update.

DISCUSSION

Issued at 157 AM CDT Mon Oct 26 2026

Currently, strong surface high pressure is centered over southern Canada, with low pressure well south in Central Rockies and Central Plains. In the upper levels, a weak upper level circulation was lifting north from northern Wyoming into southeast Montana. Isentropic ascent from the Central Plains into the Mondak region, combined with the forcing of the upper level low, is resulting in light snow over southwest ND. It's hard to tell on area webcams, but it looks like any accumulations are light and remaining in grassy areas.

For today. Expect the light snow over southwest ND to continue to work northward. Some guidance suggests that the activity may lift as far north as the Watford City area and possibly Williston. Any snow will be very light, especially north of the I-94 corridor. Current snowfall early this morning will transition to a mix, or all rain as daytime temperatures rise. By this afternoon, the isentropic upglide extends from northwest ND into the south central so don't expect much of any precip east of the Missouri River, except for south of the I-94 corridor, and moreso along the SD border. Any precip here today will be negligible as well.

Tonight a second, stronger upper level low, currently over the central High Plains, will lift into the Northern Plains. This will bring rain and snow to much of South Dakota, but over North Dakota, the trend continues to be lighter qpf over south central into eastern ND. Currently the NBM is highlighting the far south central and southeast ND as areas where we could see a quarter inch of qpf. The upper low continues to trend farther south and is more of an open wave. We may still see some light snow accumulations tonight over the south central and into the James River valley, but impacts look to be minimal.

Another upper low, currently just off the Pacific Northwest coast, will track quickly east across the Rockies, and into eastern Montana on Tuesday. A pretty compact upper low lifts from northeast Montana into southern Saskatchewan Tuesday afternoon into Tuesday evening. With a quick shot of warm advection ahead of the low within an area of steep lapse rates and decent synoptic scale lift, we could see a band of rain/snow showers lift through the northwest portion of the state Tuesday afternoon. With the current track of the system, a band of heavier precipitation would likely track to the west of the area.

Later in the week another upper low develops off the Pacific Northwest coast. there is decent agreement in the deterministic models that we see some warmer temperatures late in the workweek and into the weekend, downstream of this low. A hit or miss shower can't be ruled out, but by and large, dry conditions are anticipated in the Thursday-Friday timeframe. By the time we get to the weekend, the uncertainty ramps up quite a bit regarding the evolution of the Pacific Northwest upper low. A cluster analysis does yield some clarification for the weekend into early next week. Of the possible solutions, the most unlikely outcome looks to be a progressive trough quickly moving through. The favored solution is a slower developing upper trough, but whether we see more northern stream trough, or a southern stream trough, remains to be seen.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 629 AM CDT Mon Oct 26 2026

MVFR and occasional IFR ceilings will remain mainly over southwest and far south central North Dakota today, with areas of light snow and fog. VFR ceilings expected elsewhere. Tonight, MVFR to IFR ceilings will lift northward to the I-94 corridor by around 06Z, then north to the northern TAF sites if KXWA and KMOT by the end of the TAF period. Periods of rain and snow will be mainly confined to south central ND, along and south of the I-94 corridor. Areas of fog are possible in southwest and south central ND this evening and overnight. Expect an easterly surface flow through the TAF period, generally 5 to 15 kts this morning, then 10 to 20 kts this afternoon and tonight.

BIS WATCHES/WARNINGS/ADVISORIES

None.