textproduct: Bismarck

KEY MESSAGES

- Near average temperatures through Wednesday, then a gradual warming trend to above average through the holiday weekend. - Mostly dry through Wednesday, with more widespread chances of thunderstorms returning Thursday through the holiday weekend.

- Isolated to scattered severe thunderstorms are possible Thursday and Friday.

UPDATE

Issued at 1047 PM CDT Tue Jun 30 2026

Isolated showers across northwest and north central North Dakota have all but dissipated as expected. The cyclonic flow could maintain a stray shower from northeast Montana into northwest North Dakota beyond midnight, but dry weather is expected to prevail. Farther south, 00Z guidance is showing increased potential for a band of scattered showers developing along an axis of mid level frontogenesis across southwest and south central North Dakota late tonight into Wednesday morning. A 15 to 20 percent chance of rain has been introduced to the forecast to account for this.

UPDATE Issued at 714 PM CDT Tue Jun 30 2026

The Wind Advisory was cancelled early. Scattered showers and an occasional thunderstorm persist across northern North Dakota early this evening. These should dissipate with the loss of diurnal heating. No major forecast adjustments are needed for this update.

DISCUSSION

Issued at 140 PM CDT Tue Jun 30 2026

Currently an upper level low sits in Southern Manitoba, Canada while a large upper high is over the Southeast. Another upper low looks like its developing off the central Rockies. At the surface the cyclonic flow continues as the surface low also sits in southern Manitoba. The pressure gradient force today is causing winds to gust around 35mph currently. With a surface trough moving through at the same time, forecast wind gusts this afternoon are up to 45mph. Tonight when the diurnal mixing ends, winds will also relax. In this cyclonic flow, isolated to scattered showers and maybe a thunderstorm are possible across the north. Currently they have popped off in northeast Montana and far northwestern North Dakota.

Wednesday will be another quiet weather day as zonal flow sets up over the state, while the upper low moves northeast. There will be slightly breezy winds as the pressure gradient force lingers in the north. Thursday afternoon the active southwest flow returns along with the thunderstorm chances. This southwest flow will also bring above normal temperatures in the upper 80s to lower 90s through this weekend. Daily severe thunderstorms chances are likely Thursday through Saturday as well. On Thursday the SPC has the state in a marginal (level 1) risk. The machine learning model from CSU also has a level 1 risk for tornadoes and wind, and a level 2 risk for hail. The tornado threat is possible as the surface low will be moving through Thursday evening, adding low level spin. For Friday there is no outlook yet from SPC, but the machine learning model again hits the state for severe storms. Looks like the area (as of now) with the greatest risk is along and south of Highway 200.

Through the holiday weekend the strong southwest flow will flatten back to near zonal flow by Saturday morning. However there looks to be diffluence in the flow over the state, so don't rule out any potential of severe storms. Highs over the Fourth weekend will be hot, with highs reaching into the lower 90s. The current rain forecast through Saturday is about 30 percent, mainly in the afternoon and evening from surface heating popping storms off. This weekend is not a rain out, but keep an eye on the sky and the forecasts.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 1047 PM CDT Tue Jun 30 2026

Scattered showers and perhaps a few thunderstorms could develop across southern parts of the state late tonight into Wednesday morning, and again late Wednesday afternoon into the early evening. The probability of impacts to aviation is low, and VFR conditions are likely to prevail through the forecast period. Light westerly winds overnight will become west-northwest around 10-15 kts on Wednesday.

BIS WATCHES/WARNINGS/ADVISORIES

None.