textproduct: Bismarck

KEY MESSAGES

- Widespread shower and thunderstorm chances return this weekend, followed by near-daily low to medium chances through the work week.

- Marginal (level 1 out of 5) severe weather threat Saturday afternoon/evening over far southwest North Dakota.

- Marginal severe threat returns again Sunday afternoon/evening over southwest and parts of south central North Dakota.

DISCUSSION

Issued at 348 AM CDT Sat May 30 2026

Current surface analysis places low to the lee of the central Rockies stretching northward towards the Bighorn Mountains, while high remains over Hudson Bay. Upper level analysis places low pushing into the central Rockies, with narrow ridge stretching through the Midwest and over the Manitoba/Ontario border. Southerly flow aloft remains over our area with a variety of weak showers passing over.

For today, upper low lifts northeastward before starting to open up this evening over Wyoming/Montana. With the active pattern, shower chances will spread over much of the area and increase through the day. Instability will also be on the increase, leading to isolated to scattered thunderstorms. Strongest instability of about 500 to 1500 J/Kg remains over southwest North Dakota, though deep layer shear continues to appear rather weak. A marginal threat (level 1 of 5) remains over this area for severe weather. Forecast soundings continue to indicate that strong winds may be the main threat as storms shift into the area late this afternoon into this evening.

Sunday will see trough/low lift through Montana with periods of rain continuing over our area. Thunderstorm chances also continue, with increasing instability. Marginal severe threat also returns for the afternoon and evening hours over southwest nudging into parts of south central North Dakota.

On Monday aforementioned upper trough/low merges with another trough rotating out of the Pacific Northwest. Merged upper low loiters to our west keeping chances for showers and thunderstorms in the forecast before system flushes to the east.

Thereafter a variety of systems move through the area but timing remains in question. Therefore, low chances for precipitation remain in the forecast through the remainder of the week over various parts of the area each day.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1246 AM CDT Sat May 30 2026

Shower probabilities will increase through the night into tomorrow. Showers tonight and even thunderstorms tomorrow afternoon could cause MVFR conditions across the state and visibility reductions. Ceilings will increase by tomorrow afternoon, but there could remain some pockets of MVFR conditions. Southeast winds will continue through the TAF period.

BIS WATCHES/WARNINGS/ADVISORIES

None.