textproduct: Bismarck

KEY MESSAGES

- Low chances (20-30%) for thunderstorms southwest this afternoon into early this evening. A strong to marginally severe storm can not be ruled out, but widespread severe storms are not anticipated.

- Low to medium chances (20-40%) for showers and isolated thunderstorms tonight. Severe storms are not expected.

- Near daily low to medium chances (20-50%) for hit and miss showers and thunderstorms through the work week. - Near normal temperatures are expected today and through the upcoming work week.

UPDATE

Issued at 634 PM CDT Sun Aug 16 2026

A line of showers and storms continue to move through far southwest and south central North Dakota near the South Dakota border, with some additional showers over the far northwest near the Saskatchewan border, affiliated with a gradually approaching short wave. For early evening update, have adjusted precipitation chances accordingly, advancing the possible time of arrival ahead a bit.

DISCUSSION

Issued at 226 PM CDT Sun Aug 16 2026

Surface high pressure remains overhead across central half of the state this afternoon. Quasi-zonal flow continues across the northern plains as an upper level wave moves across eastern Montana producing showers. This wave has a low chance of initiation of strong to severe storms this afternoon in the south west as there is decent effective shear around 30 to 35 kts and MLCAPE around 1000 j/kg in eastern Montana moving into western North Dakota. There is some modest cap storms will have to overcome into order to be strong to severe. Increasing clouds coverage downstream may help to keep the cap from eroding this afternoon. The CAMS keep storms isolated to scattered across the southern half of the state with 20 to 40 percent of showers and thunderstorms this evening and tonight. A front will progress with wave pushing east of the area by tomorrow morning.

Temperature this afternoon are forecast to warm into the 80s. While overnight lows are forecast to drop down into the 50s.

Monday, temperatures will continue to warm into the 80s as an upper level ridge out west continues to strengthen. There is another low chance of strong to severe storms in the southeastern half of the state extending into the very southern edge of the James River Valley Monday afternoon. The front will be likely east of the county warning area keeping convection east of us. The aforementioned front will bring slightly cool temperatures Tuesday afternoon. Another wave could move through the region Tuesday bringing forth low to medium chances of rain across the state. Low chances for precipitation will continue on through the week tapering off by the weekend. An upper level ridge is forecast to build over the region which will lead to warmer weather. This ridge could push temperatures back into the upper 80s to lower 90s next weekend.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 634 PM CDT Sun Aug 16 2026

Isolated to scattered thunderstorms will be possible overnight, possibly lingering into the morning over parts of central North Dakota and the James River Valley. Otherwise, VFR conditions are expected.

BIS WATCHES/WARNINGS/ADVISORIES

None.