Area Forecast Discussion

KEY MESSAGES

- Western wildfire smoke may impact visibility across the Missouri valley and points west tonight through Monday.

- Less intense heat but temperatures still 5 to 15 degrees above normal through at least mid-week.

UPDATE

Issued at 856 PM CDT Sun Jul 26 2026

The Extreme Heat Warning will expire at the top of the hour. Temperatures have been falling this evening, with most locations seeing heat indices falling below 100. Expect that to continue through the evening, especially as slightly drier air moves in behind the trough tonight, which is bringing more near surface smoke into the area for tomorrow.

UPDATE Issued at 629 PM CDT Sun Jul 26 2026

Updated for 00Z Aviation Discussion below.

Only minor tweaks to the going forecast for this evening, largely to address the smoke moving into the area from ND and then the limited storm potential in Hand County. First for the smoke, been seeing visibilities down to 4-5 miles and even some ceilings around 3.5-4.5kft in western ND and expect that has already started to move into north central SD based on satellite. Like the day shift, felt like the HRRR Smoke output had a good handle on the area of thickest smoke and utilized that for the evening update and into Monday. This increased the coverage of the smoke in north central SD this evening, then settled back into generally patchy smoke through Monday across the rest of the area. As for the thunder potential, haven't seen too much vertical development along the CU field in southeastern Hand and southwest to Chamberlain. Did add a very low end slight chance (15%) to that area earlier this evening, but with limited forcing (only weak boundaries in that area), didn't want to go much higher than that. So far, that seems to be a good call and would expect the CU field to gradually diminish with time as peak heating is lost. If something gets going, the environment is favorable for severe threat (MLCAPEs over 4k J/kg, limited CIN, and effective shear of 35-40kts). But would likely be very short lived in our CWA if storms developed with the storm motions having storms slide southeast around 20kts.

DISCUSSION

Issued at 149 PM CDT Sun Jul 26 2026

Mid-level disturbance has pretty much cleared the CWA, with cloud cover and showers exiting to the south and east. Plenty of sunshine across the CWA this afternoon as temperatures rise through the upper 80s and 90s. Still several more degrees to go before the end of the day, all the while dewpoints remain high for many areas. Quite a few locations are already seeing heat indices from 105 to 110 early this afternoon. No plans to change headlines and will let things expire at 02Z this evening. Still appears there isn't a need to extend it at this time as temps/dewpoints on Monday are coming in a tad lower than what we saw this weekend. This keeps forecast apparent T's below 100 across much of the CWA.

Also watching convection chances this afternoon. CAMs continue to show limited potential over the CWA, but will be keeping an eye on any developing cumulus within the weak surface trough later this afternoon. If there is any initiation, it would be within this trough as it eventually sets up over southeast SD.

Will need to monitor smoke trends overnight as HRRR-smoke product shows increasing concentration of smoke aloft and at the surface tonight through the day Monday. Satellite imagery shows quite a bit of smoke aloft across western ND and MT, even some of this making it to the surface as witnessed by a handful of obs from 5-9SM. Followed trends of increasing surface smoke concentration in the HRRR to add patchy smoke wording to portions of the CWA tonight through the day Monday.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 629 PM CDT Sun Jul 26 2026

Terminals KABR,KATY,KPIR,KMBG

Smoke is the primary concern for much of the forecast, as it moves into the area from the northwest tonight. Have it the worst at KMBG, as upstream obs in ND have shown visibility down to 4-5SM and even some ceilings at 3.5-4.5kft. So hit on that potential into this evening, but with the loss of light scattering heading into nighttime hours, we may not see as reduced of visibilities. For the rest of the area, tracked the smoke based on the HRRR smoke output and included 6SM later tonight or tomorrow morning and through the rest of the day tomorrow. There is the potential for storms moving into the area from western SD tomorrow evening, but should be beyond the forecast period.

ABR WATCHES / WARNINGS / ADVISORIES

SD...None. MN...None.