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 has been issued for the the the northern /eastern two thirds of Minnesota and most of Wisconsin through late week 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 1250 PM CDT Tue Jul 14 2026

Another afternoon with not a cloud in the sky across southern Minnesota and western Wisconsin. Midday temperatures remain in the upper 80s and will soon climb into the 90s for the 4th day in a row (at MSP). To breach the top ten longest stretch for highs in the 90s at MSP, we would need at least 9 days of highs in the 90s. It is possible we see highs in the 90s through Sunday, but uncertainty has been introduced with the addition of smoke from wildfires into the equation. All things remain true about ridge placement and the weak surface front to the north contributing to heat and humidity through the end of the workweek. This includes limited overnight relief and a compounding heat stress. The addition of smoke will complicate, likely limit, forecast high temperatures Wednesday through Friday. An Air Quality Alert has been issued for all MPX counties in Wisconsin and most counties north of the Minnesota River Valley in Minnesota as a result of the incoming smoke. The smoke will arrive behind a stationary front Wednesday morning for most, quickly plummeting air quality as it does. There is some uncertainty with how far south the boundary will stall, but hi- res models depict a secondary southerly push on Thursday. Combining the extended heat and humidity with unhealthy air quality will only act to exacerbate health impacts Wednesday through Friday this week. The ridge will keep any chance for precipitation well away from the area. This means that along with the heat will come a gradual exacerbation of drought conditions, but no alarm bells are going off yet. One relatively positive outcome from the smoke is that it will limit highs for Friday, likely reducing the need for an expansion or extension of heat headlines as we previously mentioned.

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 the 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.

WEEKEND INTO EARLY NEXT WEEK...The arrival of the weekend will signal the end of the most intense heat and a trend towards a slightly cooler pattern by early next week. Forecast guidance depicts lowering heights with the passage of an initial wave over Lake Superior on Saturday. Despite the lowering heights, the antecedent warm mid-level air mass will still yield highs in the upper 80s to lower 90s per the latest NBM (The caveat here is the potential for a wildfire smoke scenario to linger longer than currently forecast, which could end up lowering weekend high temperatures a tad). A stronger secondary shortwave is progged to track from south central Canada into the Great Lakes Sunday into Monday and will bring notably cooler temperatures into the Upper Midwest by the middle of next week (highs in the low to mid 80s). The approach of the shortwave will also signal an increase in slight chance to chance PoPs across eastern MN/western WI Sunday PM/Monday. Still a long way to go, but conceptually the retreating ridge and southern track of the shortwave would support the ~40-50 percent of GEFS/EPS members that feature measurable precipitation (up to a few tenths) during this timeframe. A classic large scale longwave ridge- trough pattern sets up for second half of next week, with a ~590s dm ridge over the Four Corners region/south central CONUS and deeper troughing over the Great Lakes. Initially, this pattern places northwesterly flow across the Upper Midwest and guidance tends to be on the drier side. Eventually flattening of the upper-flow around the ridge may bring a more active track across the Plains, but confidence in long range forecast evolution is low at this time.

AVIATION /00Z TAFS THROUGH 06Z THURSDAY/

Issued at 620 PM CDT Tue Jul 14 2026

The main component of the TAF will be the introduction to lowering visibility and impacts due to wildfire smoke arriving from north to south after 12z. Due to confidence, kept the lowest visibility to 6sm for now, however some sites might get lower, mainly AXN/STC. Winds will be relatively light and variable throughout, allowing the smoke to linger towards the end of the period.

KMSP...High resolution guidance keeps the worst of the smoke north of Hennepin County, making it as far south as Anoka/Washington counties. We will need to monitor this trend in future TAFs to see how low visiblity may get.

/OUTLOOK FOR KMSP/ THU...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.