textproduct: Bismarck

KEY MESSAGES

- Dangerous heat this weekend through Monday, with daily maximum temperatures and heat index values in the upper 90s to near 110, and overnight lows in the upper 60s to upper 70s.

- Very little to no chances for showers and thunderstorms through Monday.

- Cooler north mid to late next week, but still hot across southern North Dakota. Daily low to medium shower and thunderstorm chances also return mid to late next week.

DISCUSSION

Issued at 215 AM CDT Sat Jul 11 2026

Upper level ridging continues to build over the northern Plains, setting the stage for dangerous heat developing today and continuing into early next week.

Currently, a surge of warm advection lifting northeast through the forecast area has produced a small area of convection that is racing quickly east through north central ND at this time. Added a small area of pop to cover the remainder of the overnight. Additional convection over eastern Montana continues to struggle as it advances slowly eastward. Anticipate this convection having a hard time making it into ND this morning but will continue to monitor and can add some small pops if needed.

The main forecast issue will be the dangerously hot temperatures. NBM ensemble spreads remain pretty low today through Monday, so confidence remains high in very hot, near record to record high temperatures, especially Sunday and Monday. In addition, record high minimum temperatures are quite possible Sunday night into Monday morning. As mentioned yesterday, there is a minor, but definite drop in the ensemble temperatures, but an increase in the ensemble spread. The drop is more pronounced in the north and we may end up seeing a pretty large range in temperatures from the Canadian Border to the South Dakota border next week. With the cooler temperatures north from the flattening of the upper ridge, we do see low to medium thunderstorm chances enter the forecast Tuesday night and Wednesday across the north. Then more of a broad brush of low pops across the entire forecast area through the remainder of the workweek as uncertainty increases as to whether the ridge pops back up, or remains flattened.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1150 PM CDT Fri Jul 10 2026

VFR conditions are expected at all terminals throughout the 06Z TAF period. Patchy fog could develop near KJMS and surrounding areas late tonight into early Saturday morning, but confidence remains too low to include visibility reductions at this time. Light southeasterly winds overnight will become southerly and increase to around 10-20 kts Saturday afternoon, with some higher gusts possible, winds diminish a little Saturday evening, but remain a little breezy through the evening.

BIS WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning from 1 PM CDT /noon MDT/ this afternoon to 1 AM CDT /midnight MDT/ Tuesday for NDZ001>005-009-010-012- 013-017>020-022-023-025-031>033-035>037-040>044-046>048-050- 051-055>062.