textproduct: Bismarck

KEY MESSAGES

- Showers west and north central this morning, then scattered showers and thunderstorms statewide this afternoon.

- Near to below average temperatures favored through early next week, with highs mostly in the 60s and 70s and lows mostly in the 40s.

- Breezy northwest winds expected today through the weekend.

DISCUSSION

Issued at 410 AM CDT Thu Jun 11 2026

Early morning upper air analysis shows mean troughing from the Canadian prairie provinces through the Northern Plains, with several embedded shortwaves and closed low circulations. One of the shortwaves is paired with a surface cold front, which is bringing widespread light to at times moderate rainfall across northwest and north central North Dakota early this morning. The rain is expected to continue pivoting southeastward through mid morning, reaching much of southwest but little of south central North Dakota before the synoptic scale forcing rapidly wanes. But from early to mid afternoon, scattered to numerous showers and isolated to scattered thunderstorms are forecast to develop across much of the state under the cyclonic flow regime. SBCAPE could approach 1000 J/kg, but mid level lapse rates are only forecast around 6 C/km with effective bulk shear no greater than around 20 kts. Severe storms are therefore not expected, but some small hail could occur given the cooler air mass with seasonably low freezing levels. Gusty winds are also possible with thunderstorms, but may not greatly exceed the already gusty background winds that are forecast out the northwest around 20-30 mph with gusts to 35-45 mph. Below normal high temperatures in the mid 60s to mid 70s are expected this afternoon. Shower and thunderstorm activity should mostly dissipate with the loss of diurnal heating this evening, but a few stray showers could linger into the overnight hours. Lows tonight will mainly be in the mid 40s to lower 50s.

Northwest cyclonic flow aloft will continue over the Northern Plains on Friday as several shortwaves rotate around a closed upper low over northeast Manitoba and northwest Ontario. Most CAMs are simulating isolated to widely scattered showers and thunderstorms focused along a baroclinic zone from west central to southeast North Dakota Friday afternoon and early evening, along with weaker diurnally driven shower activity across the north. Similar mid level lapse rates and slightly weaker CAPE are forecast for Friday compared to today. Effective bulk shear could be stronger, but model soundings show mid to upper level capping resulting in much lower equilibrium levels for surface- based parcels. This yields a similar threat ceiling for any thunderstorms on Friday as that for today, with small hail and gusty winds possible but severe weather not anticipated. A slightly enhanced geographic contrast in high temperatures is forecast on Friday, ranging from the mid and upper 60s far north to around 80 in the southern James River Valley. Breezy northwest winds also remain in the forecast for Friday.

The cyclonic flow regime continues through the weekend as a closed upper low sits over Ontario. Deterministic guidance suggests another shortwave trough swinging through the Northern Plains on Saturday. This would in theory be a prime setup for another round of afternoon showers, but model soundings show a capping inversion on top of a shallow boundary layer. No change to the wind forecast on Saturday, but it does look to be the coolest day with highs only in the 60s. The NBM also shows Saturday night to be the coolest night, with lows in the 40s. Far western North Dakota may be in close enough proximity to a Montana surface high pressure to provide a favorable radiational cooling set up that could allow temperatures to fall into the upper 30s in low-lying, sheltered areas. A slight warm up with a continuation of dry and breezy conditions is in the forecast for Sunday.

Ensemble guidance maintains a northwest flow pattern through at least the middle of next week, but mean troughing shifts more over the eastern CONUS while a ridge tries to build over the west. The NBM maintains a 20 to 30 percent chance of showers and thunderstorms on Monday, followed by similar chances on Wednesday with what looks to be a clipper-type system. This favored pattern allows for a slight warm up early to mid next week, but still with near to below normal temperatures and breezy northwest winds prevailing.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 410 AM CDT Thu Jun 11 2026

Light rain with MVFR ceilings will continue spreading into western and north central North Dakota early this morning. The rain may taper off before reaching south central North Dakota, but a period of MVFR ceilings is still anticipated at KBIS. KJMS has a lower probability of MVFR ceilings later this morning. Scattered showers and thunderstorms are expected to develop across much of western and central North Dakota this afternoon, diminishing by mid evening. Brief heavy downpours from showers and storms could reduce visibility to MVFR or IFR levels. Winds are forecast to become northwest around 15-25 kts this afternoon, with gusts to 25-35 kts.

BIS WATCHES/WARNINGS/ADVISORIES

None.