textproduct: Bismarck

KEY MESSAGES

- Temperatures will remain hot through the middle of the week, with highs mostly around 90 to 100.

- An isolated strong to severe thunderstorm could enter far southwest North Dakota Monday afternoon and early evening.

- Precipitation chances are low until Wednesday evening through Thursday when there is a 30 to 60 percent chance of showers and thunderstorms across much of the state.

UPDATE

Issued at 124 AM CDT Mon Jul 27 2026

No major forecast changes are needed for this update. Visibility reductions from smoke have marginally improved since the evening, but are still in the 6 to 10 mile range on a widespread basis.

UPDATE Issued at 922 PM CDT Sun Jul 26 2026

A weak cold frontal boundary has passed through all but the far southern James River Valley of ND, with the main impacts being a wind shift to the northwest and much drier air in its wake. However, temperatures themselves are only marginally cooler behind than ahead of the front. Nevertheless, with drier air in place, heat indices have rapidly dropped in most locations. Therefore, the Heat Advisory has been allowed to expire on time.

UPDATE Issued at 642 PM CDT Sun Jul 26 2026

Smoke propagation continues further southeast than models have predicted, therefore went ahead and expanded patchy smoke mentions across the remainder of the forecast area. Based on upstream observations, smoke is likely to stick around most of the area through at least Monday morning. Otherwise, dry and hot conditions continue across the state early this evening.

DISCUSSION

Issued at 328 PM CDT Sun Jul 26 2026

Very hot and smoky weather continues. Public report from Williston indicated smoky conditions with the smell of smoke in the air. The latest visibility observation from Williston has dropped to 4SM. Latest satellite imagery shows smoke rolling in from Montana. There is a rather sharp cutoff just north of the International border, with much less smoke in Canada. Upper level winds are keeping most of the smoke confined to the Continental U.S and there is a definite thickening of the smoke along the International Border. It remains smoky as you go south, but smoke concentration is less. Have expanded the smoke to include much of western and central ND.

The Heat Advisory remains in effect through 9 PM CDT this evening. There were considerations of expanding this through tomorrow in the southwest but in the end we decided to hold off on this. Forecast lows tonight are generally in the low to mid 60s, while last night lows were in the upper 60s to lower 70s. Although not cool by any stretch of the imagination, the lower temperatures will limit the overnight heat impacts. There are some differences in forecast highs tomorrow, and in the end, felt there was too much uncertainty to continue the Advisory. We still may need to issue something overnight for the far southwest and/or south central, but will hold off for now. Forecast highs Monday are generally in the 90s. A few 80s may be found in the far north, and a few readings of 100 to 103 are possible in the southwest and south central, generally along and south of the I-94 corridor.

The NBM has been carrying a low chance (around 20 percent) probability for thunderstorms tomorrow, generally in the southwest and south central. Highs are around 100 degrees and there will likely be some capping issues, but there could be some moderate instability during the max heating of the day within an area where shortwave energy is propagating through the upper level ridge. Better probabilities remain south of the forecast area, but given the heat, and for consistency will maintain these pops.

The remainder of the workweek looks to be not quite as hot as this weekend, but we still remain 10 to 15 degrees above normal (normal is in the lower 80s) in most areas. With the hot temperatures and impulses propagating through the mean upper ridge, generally low pops (20 to 30%) are anticipated through the week. A more vigorous wave does move through the mean flow in the Wednesday night through Thursday timeframe. Currently the NBM is depicting a broadbrush area of 30 to 60 percent pops. We will see if these pops remain that high, but the large uncertainty in timing and placement does necessitate the broadbrush nature of the pops at this time.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 124 AM CDT Mon Jul 27 2026

Smoke from distant wildfires is expected to remain thick aloft through the forecast period. Surface visibility restrictions from the smoke are less certain, but MVFR could return to parts of the region on Monday. Aside from the smoke, VFR conditions are expected through the forecast period. A few showers and thunderstorms are possible in southwest North Dakota during the day Monday, with virga possible to the north and east. Some gusty winds could be associated with showers or storms. Otherwise, winds should remain around 10 kts or less with varying directions.

BIS WATCHES/WARNINGS/ADVISORIES

None.