textproduct: Bismarck

KEY MESSAGES

- Much cooler this weekend, before slowly warming next week.

- High chances (60-90%) for rain Sunday night through Monday.

- Windy weekend, continuing into early next week.

UPDATE

Issued at 1259 AM CDT Sat Sep 12 2026

For late night update, only change was to add some low shower chances along the South Dakota border given radar returns are picking up a bit. With that said, any possible accumulation would be minimal at best.

UPDATE Issued at 925 PM CDT Fri Sep 11 2026

Water vapor imagery shows zonal flow across the Northern Plains with varying cloud thickness and height. There are lower and thicker cloud decks creeping into the southwest corner of the state. Radar has started to pick these clouds up. This can bring a stray and very brief shower, but confidence is low (less than 5-10%) if any rain reaches the ground.

UPDATE Issued at 558 PM CDT Fri Sep 11 2026

Current MRMS shows a band of light rain showers moving across the north central portion of the state. Minot Airport has recorded a Trace so far. Showers will continue to move east and slowly dissipate in the next 2-3 hours. Winds have already peaked in speed for the day and they will also start to wind down for the remainder of the evening.

Main forecast is on track.

DISCUSSION

Issued at 125 PM CDT Fri Sep 11 2026

The Northern Plains are mostly dominated by zonal flow, with a small shortwave embedded over Montana currently. A large upper level low system sits near Vancouver. At the surface the previous cold front has now made it all the way through North Dakota, so temperatures across western and central North Dakota are only in the mid 60s to lower 70s. A surface low pressure sits in east central South Dakota, with a pressure gradient affecting the eastern half of North Dakota, where winds are gusting around 20 mph. That upper level shortwave has created a narrow band of rain showers laid across eastern Montana, on an eastern track. The NBM has very little PoPs for these showers in North Dakota, so we had to manually add those in. These showers should track across northern North Dakota and slowly dissipate this evening.

As this zonal flow continues into the weekend, the below normal cooler temperatures will too. Tonight expect lows in the 40s again, then highs Saturday in the low to mid 60s. This trend will continue for Sunday as well. Saturday will be windy across the eastern half of the state as the surface low slides into western Minnesota, producing a strong pressure gradient across North Dakota. Northwest winds 15 to 30 mph are forecast.

Heading into Sunday and Monday that upper level low will slide into Montana, creating strong southwest flow over the Northern Rockies. This will create a surface low pressure that moves into the Dakotas, producing widespread rain Sunday night through Monday. With this surface pressure, another strong pressure gradient will occur. Sunday winds will be the strongest across the southwest where southeast winds 25 to 40 mph are forecast. Monday will be slightly windier with a frontal passage. Current NBM forecast winds across the west are 30 to 50mph, lower east. We will keep an eye on this for a possible Wind Advisory or Warning. The backside of this system will allow slightly warmer 850mb temperatures to come back north, warming our temperatures back into the mid 70s by the end of next week along with low chances for rain.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1259 AM CDT Sat Sep 12 2026

Isolated rain showers will be possible along the South Dakota border this morning, but any visibility restriction is expected to be minimal. Otherwise, VFR conditions are expected to prevail.

BIS WATCHES/WARNINGS/ADVISORIES

None.