textproduct: Bismarck

KEY MESSAGES

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

- Patchy dense fog possible southwest and south central tonight into Tuesday morning.

- Another system may bring light rain to portions of northwest North Dakota Tuesday into Wednesday.

UPDATE

Issued at 706 PM CDT Mon Oct 26 2026

For early evening update, main change was to speed up the entrance of precipitation from the south, as it has moved in a bit quicker than previously forecast. Otherwise, remainder of forecast continues to be on track.

DISCUSSION

Issued at 127 PM CDT Mon Oct 26 2026

The forecast area sits in between large surface high pressure over south central Canada and surface low pressure over the Southern High Plains. This is advecting moister air into the Northern Plains. Through this afternoon and tonight, high pressure will gradually churn eastward towards Ontario, while surface low pressure deepens and propagates northeastward with associated shortwave aloft lifting through the area. This will result in precipitation currently organized over South Dakota to lift into the state.

Currently, most hi-res models suggest that the heaviest precipitation will remain along and south of I94 east of the Missouri River, and then a little further north as one moves further east across the state. However, historically speaking, models tend to have a hard time resolving large Canadian high pressure systems in that they tend to saturate things too far north. And often times, saturation through the column is difficult under the northern edge of the observed precipitation shield. In other words, even if organized radar echoes make it to I94 and north, they may have a difficult time squeezing out meaningful moisture.

In regard to precipitation types, surface temperatures will likely remain warmer than the NBM due to cloud cover. However, even the NBM90 maintains most temperatures near or below freezing. This would make sense as BUFKIT model forecast soundings suggest that, assuming dry air aloft is able to be overcome, deep saturation should allow for temperatures to wetbulb out below freezing near the ND/SD border. This favors snow development, though duration could be fairly limited. Overall, accumulating snow remains possible mainly south of I94, and mainly on grassy surfaces. NBM ensemble probabilities of measurable snow are in excess of 70 percent for much of the area east river, south of I94, and west of Highway 281. However, the probability of an inch or more is now down to around 30 percent for parts of the same geographic area. Of note, some soundings do show a loss of ice on the backside as precipitation begins pulling off to the east. Depending on whether or not surface temperatures dip below freezing, this could result in brief freezing rain or freezing drizzle.

As any precipitation begins to move off to the east, very low-level stratus and possibly fog will develop in its wake. Depending on how strong near-surface winds are, patchy dense fog could develop, especially over elevated terrain in the southwest. Skies should begin to clear out from west to east on Tuesday with flow aloft becoming more zonal through the middle of the week, and southwesterly towards the end of the workweek. Overall, this should result in a gradual warming trend with temperatures becoming seasonably warm for the latter half of the week with highs mostly in the 40s north to 50s south.

Tuesday afternoon could see light rain mainly in the northwest as weak shortwave energy lifts through the region, while Wednesday could see rain in the southeast. Otherwise and overall, mostly dry conditions should prevail Tuesday through Thursday night. After which, periodic low precipitation chances, mostly in the form of rain, are in the current forecast to finish out the week and into early next week.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 706 PM CDT Mon Oct 26 2026

Widespread precipitation over northern South Dakota nudging into far southern North Dakota will continue to lift north through tonight. This will result in some light rain and snow mainly in the south central and southeast parts of North Dakota. The more widespread impacts in regard to aviation are low-level stratus resulting in LIFR ceilings tonight through Tuesday for most areas along and south of I94, and IFR ceilings for most areas further north. In areas where LIFR ceilings develop, stratus may reach the surface resulting in patchy fog that could become dense at times. The highest confidence in patchy dense fog development is over more elevated terrain in the southwest.

BIS WATCHES/WARNINGS/ADVISORIES

None.