textproduct: Bismarck

KEY MESSAGES

- Low to medium chances (20 to 40 percent) for thunderstorms through tonight. An isolated severe storm is possible, mainly in the south.

- Showers and thunderstorms could return again Tuesday through Tuesday nigh. Isolated to scattered severe storms are possible, especially in the south.

- Near average temperatures through Tuesday, with a cooling trend then expected through the end of the work week.

UPDATE

Issued at 1001 PM CDT Mon Aug 10 2026

A 300 mb jet is kicking off more convection across the west south of Dickinson. There is still plenty of MLCAPE and shear to sustain strong to severe storm, however CIN has increased and could hinder storm development. No updates are needed at this time.

UPDATE Issued at 602 PM CDT Mon Aug 10 2026

A 300 mb jet streak continues to lift convection north I-94. However, instability continues to decrease across the state. There is a cumulus field forming in the southwest near the surface wind field which is converging over Bowman county. This is where most of the instability is with ample shear, but the boundary storms are firing around continues to push southward out of the state. So if storms do fire they will likely dive southeast into south Dakota. CIN will also increase as temperatures decrease which could hinder convection. No major updates are needed at this time as the forecast remains on track.

DISCUSSION

Issued at 242 PM CDT Mon Aug 10 2026

Stalled frontal boundary remains across the south, while a plume of low level moisture extends from central to northeastern portions. Overall abundant instability will be found across the southern half of the state this evening, possibly becoming uncapped, at least briefly. Shear will also remain high tonight as a decent jet remains aloft. The limiting factor will be the lift mechanism for tonight. Surface boundary combined with a weak upper level wave could be enough to produce at least some isolated thunderstorms. Although the better lift and moisture may be to our south tonight. SPC has maintained a Marginal Risk for most of southern ND through tonight to account for this isolated conditional severe weather threat. Otherwise look for lows in the 50s tonight. Increased low level moisture combined with some light winds could bring some fog tonight, especially in the southwest. More showers and thunderstorms could return on Tuesday as this boundary lingers. Inverted surface trough moves more into western ND Tuesday afternoon. Meanwhile high amounts of instability and shear also look to be found. Instability may even be uncapped by mid afternoon Tuesday. CAMs consistently showing storms firing ahead of the surface trough as a result and moving from west to east Tuesday afternoon and evening. Shear and instability will be high enough for golf ball sized hail and wind gusts up to 70 mph. Depending how the shear vector sets up, multi cluster to supercell storm mode is possible. If supercell storm mode materializes then perhaps some larger hail is possible. Tornado threat both tonight through Tuesday night also looks low as LCLs are high and hodographs are not quite curved enough. Overall SPC has a Day 2 Marginal to Slight Risk for Tuesday to account for a potentially more widespread severe weather threat. Biggest uncertainty being if the surface trough provides enough lift for thunderstorm initiation. Otherwise look for near normal temperatures in the 80s on Tuesday. Lows Tuesday night will be in the 50s. Light winds and high humidity values could also see patchy fog return Tuesday night.

Wednesday through Friday, cooler temperatures look to move into the area along with near daily chances for showers and thunderstorms especially across the west and south. CSU-MLP showing some low chances for isolated severe weather on Wednesday, as shear remains high yet expect lower instability. After Wednesday CSU-MLP not showing much for severe weather chances this week. Today's models continue to show a more robust wave and surface low moving through sometime Thursday through Friday. Increased southerly flow ahead of this wave could also bring increased PWAT values and perhaps QPF. NBM even showing a 30 to 60 percent chance of at least an inch of liquid in a 24 hour period Thursday night through Friday across much of western and some of central ND during this time period. Isolated shower and thunderstorm chances then look to linger into the weekend, although depending on track of a surface high this could further lower these chances. Temperatures may increase slightly yet still remain below normal.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 602 PM CDT Mon Aug 10 2026

VFR conditions will continue across the region this evening and most of tonight. There is a possibility for fog forming along the North and South Dakota border tonight. Winds will shift to northeast tonight and back to southerly by tomorrow morning. Thunderstorms are possible tomorrow afternoon and may be a storm or two tonight, however confidence is low on timing and location of storms.

BIS WATCHES/WARNINGS/ADVISORIES

None.