textproduct: Bismarck

KEY MESSAGES

- Hot and smoky conditions continue through at least the middle of the week, with highs around 90 to 100.

- Medium to high chances (40 to 70 percent) for showers and thunderstorms Wednesday afternoon through Thursday. Some storms could be severe, especially in the west half of the state Wednesday afternoon and evening.

- Slightly cooler Thursday and Friday, but hot conditions could return for the weekend.

UPDATE

Issued at 157 AM CDT Wed Jul 29 2026

A Heat Advisory has been issued for counties that surround the Missouri River and along the I-94 corridor west of the river for Wednesday afternoon and early evening. High temperatures and maximum heat index values are forecast around 100 degrees. The only change to the near-term forecast was to add patchy fog to north central North Dakota, where some lower visibility has already been observed, along with light winds, a clear sky, and near-zero dewpoint depressions.

UPDATE Issued at 1041 PM CDT Tue Jul 28 2026

Thunderstorms remain in South Dakota as quiet weather continues across the region. No updates are needed at this time.

UPDATE Issued at 609 PM CDT Tue Jul 28 2026

Storms continues across the southeastern Montana and northwestern South Dakota. Some of these storms could move into the southwest this evening. Quiet weather continues across the state.

DISCUSSION

Issued at 132 PM CDT Tue Jul 28 2026

Currently, scattered showers and isolated thunderstorms continue to propagate east from eastern MT into western ND. Instability is limited here and CIN continues to increase over western ND this afternoon, so the threat for thunderstorms remains low here. Over eastern ND, instability is much more concerning with 2500 J/Kg of MLCape situated over the northern James River Valley with little capping and convective temperatures in the low to mid 90s (current temps around 90). Forecast HRRR soundings indicate a marginally severe potential should convection develop. A limiting factor is building upper heights and the lack of forcing for ascent this afternoon, combined with a general drying of the lower boundary layer. Cams have been back and forth as whether or not to develop convection here today. Currently, a couple of the CAMS are showing at least an attempt at convection, while a majority remain dry. If we would see convection from the Turtle Mountains into the James River Valley a stronger to marginally severe storm can not be ruled out. For most, this afternoon and tonight will be dry.

Wednesday will be another hot day across western and central ND. Afternoon high temperatures range mostly from the mid 90s to near 103, with the hottest temperatures over the west central and southwest. Heat Advisory criteria may be met, generally in areas south and west of the Missouri River. However, the areal extent of advisory criteria heat indices is low. There are also some concerns regarding cloud cover from convection, limiting temperatures if it develops earlier in the day. In addition, the southwest portion of the state will probably see some of the lower dewpoint in the area Wednesday afternoon, limiting heat indices to below the actual air temperatures. Will let later shifts monitor for possible highlights tomorrow.

Another concern Wednesday will be the threat for severe storms. SPC has upgraded pretty much the western half of the state to a slight chance (level 2 out of 5) for severe storms. In general, it looks like storms will develop over eastern Montana Wednesday afternoon and move into western ND through early evening. Damaging winds will be possible given the inverted V soundings. Large hail will also be possible given the steep lapse rates and increasing winds aloft. We will message the same hazards as the previous forecast, golfball sized hail and 70 mph winds. Storm mode looks to be more linear north with bulk shear vectors more parallel to the surface trough, while they are more perpendicular south, indicating more of a supercell threat. With a surface low over eastern Montana and strong surface heating, there could be a window of opportunity for a tornado early on, in the northwest where LCL heights will be more favorable. Cams are pretty consistent in convection not holding together as it moves into a less favorable environment over central ND. This then muddles the picture for potential convection on Thursday. There is currently a marginal risk for severe storms across most of the forecast area on Thursday. We will keep messaging general for Thursday at this time as a lot will depend on how things evolve tomorrow. Bulk shear definitely looks to be weaker and Cape also looks like it may be lower with more cloud cover remaining over a good portion of the forecast area.

Thursday and Friday will be cooler (relatively) with highs in the mid 80s to lower 90s Thursday, and mid 80s to mid 90s Friday. We then warm back up over the weekend with some 100 degree readings possible once again Saturday and especially Sunday. Heat headlines may once again be in play. Fire weather concerns may also be heightened by Sunday as grasses continue to cure and we see stronger southerly winds develop Sunday afternoon. Another cooldown does look to be in store for at least the beginning of next week.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 157 AM CDT Wed Jul 29 2026

Smoke from distant wildfires will likely persist through the forecast period. MVFR visibility cannot be ruled out from time to time, but VFR conditions should mostly prevail. Scattered showers and thunderstorms are forecast to develop in western North Dakota by Wednesday evening and spread eastward into the overnight hours. A few storms could be severe with damaging wind gusts. Winds are otherwise expected to be southerly around 10-15 kts on Wednesday.

BIS WATCHES/WARNINGS/ADVISORIES

Heat Advisory from noon CDT /11 AM MDT/ today to 8 PM CDT /7 PM MDT/ this evening for NDZ009-010-017>020-031>033-035-041- 042-046-057>062.