textproduct: Twin Cities

KEY MESSAGES

- Dangerous heat wave continues this week. This is a long duration and cumulative threat due to daily highs in the 90s, heat indices approaching 100 degrees, and little relief overnight.

- An Air Quality Alert remains in place for much of northern through east central Minnesota into western Wisconsin through Thursday due to an expected plume of heavy smoke moving south along frontal boundary.

- No precipitation expected until Friday at the earliest, and mainly for western Wisconsin with low chances at that.

DISCUSSION

Issued at 304 AM CDT Wed Jul 15 2026

The forecast continues to run very similar from previous days for the WFO MPX coverage area with highs in the lower 90s (potentially as high as 95 in the TC metro counties) and a nearly cloudless sky. This is due to surface high pressure remaining anchored over the mid-upper Mississippi River Valley and the apex of 500mb high pressure ridging (again reaching 600dam per the 15/00z MPX RAOB) sitting over the region. Surface analysis does show the west-to-east quasi-stationary frontal boundary sitting over ND into northern MN into the Great Lakes, with actual showers/t-storms dotted along it for northern MN. This wouldn't necessarily be a bad thing to receive precipitation for northern MN due to the wildfires, however the additional lightning hazard with dry antecedent conditions up north could spawn additional wildfires, which is now going to be a hazard for our portion of MN and WI. With upper level flow dragging the wildfire smoke southeastward into our coverage area, and even the slogging southward progression of the aforementioned front aiding in bringing smoke our way, air quality will be impacted thus the issuance of the Air Quality Alert for much of our central-eastern portions of our coverage area. There continues to be some wobbling in the placement of the front, particularly how far south it may come, which would determine how far south the smoke will ultimately reach. While there is high confidence on precipitation remaining away from our coverage area through Thursday, and even Friday for most of the coverage area (only western WI has small chances for precipitation), the coverage and depth of smoke becomes a serious wild card for what happens with temperatures, and thus the intensity of heat impacts. There was some thought to extending the heat headlines out through Friday with highs still in the mid 90s and a small uptick on dewpoints due to the expectation that the front will lift back north on Friday. However, with such uncertainty to how the smoke will impact the area today and tomorrow, have held off any adjustments to the heat headlines at this time and will allow time to monitor observations both at the surface and aloft.

Still, the ongoing precautionary message remains: Regardless of if there is a headline out for a given county or of what type, the hazards of and precautions for excessive heat and air quality need to be recognized and accounted for. As noted in previous discussions, continue to practice Heat Safety, but now accounting for air quality as well: Stay hydrated, check on the elderly, immunocompromised, and those without A/C, check the backseat of the car, and limit time outdoors.

While Friday may produce a weak few isolated showers/t-storms over western WI in association with weak isentropic lift due to the nearby front, the area will still be dominated by the broad upper level ridge. However, the ridge will retreat westward late Friday into the weekend, and then collapse going into early next week. This will not yet result in a widespread airmass change, thus highs will still reach the upper 80s to lower 90s over the weekend with no precipitation expected. The modest pattern change looks to come Monday onward as a large H5 low looks to drop southward from northern Hudson Bay, allowing for a more western ridge/eastern trough pattern for the CONUS early-to-mid next week. This will result in highs falling back to the lower 80s while also having small increases in precipitation chances as weak mid-level disturbances round the fringes of the upper level low. This wouldn't be enough to bring soaking rains or mitigation for drought conditions, but it could produce some showers/t-storms here and there. Nevertheless, the break from day after day of the elevated heat would certainly be welcome going into late July.

AVIATION /12Z TAFS THROUGH 18Z THURSDAY/

Issued at 636 AM CDT Wed Jul 15 2026

Areas of MVFR/IFR dense fog will continue to mix out over the next couple of hours. Hence added tempo groups for any near-term vsby impacts. Winds forecasted to be light and variable through the period. Main concern remain the impact of wildfire smoke that will be advecting in from the northeast this afternoon. Smoke guidance continues to keep greater visibility impacts north and east of our sites however models have supported MVFR for vsby for STC, RNH, EAU and MSP. AXN could see smoke as well but given the site's proximity to the smoke axis, decided to keep in VFR for now. MKT and RWF continue to appear smoke free per latest guidance. Smoke will linger into the next period however expect VFR vsby to return by late evening. Another shot at MVFR/IFR fog will be possible tomorrow morning.

KMSP...Maintained mentions of MVFR 5SM visibility for wildfire smoke mainly between 22 and 05z timeframe. Smoke will likely linger into the next period however anticipate VFR 6SM or more returning closer to midnight.

/OUTLOOK FOR KMSP/ THU PM...MVFR vis w/FU. Wind SW 10-15 kts. FRI...VFR. Wind SW 10-15kts. SAT...VFR. Wind N 10-15kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...Extreme Heat Warning until 9 PM CDT Thursday for Anoka-Benton- Blue Earth-Brown-Carver-Chippewa-Chisago-Dakota-Douglas- Goodhue-Hennepin-Isanti-Kanabec-Kandiyohi-Lac Qui Parle- Le Sueur-McLeod-Meeker-Mille Lacs-Morrison-Nicollet-Pope- Ramsey-Redwood-Renville-Rice-Scott-Sherburne-Sibley- Stearns-Stevens-Swift-Todd-Washington-Watonwan-Wright- Yellow Medicine. Heat Advisory until 9 PM CDT Thursday for Faribault-Freeborn- Martin-Steele-Waseca. WI...Extreme Heat Warning until 9 PM CDT Thursday for Barron- Chippewa-Dunn-Eau Claire-Pepin-Pierce-Polk-Rusk-St. Croix.