textproduct: Twin Cities

KEY MESSAGES

- Wildfire smoke will improve, but could return behind the frontal passage later today (highest chance for more smoke is in WI).

- One more day of dangerous heat today until a cold front helps to cool us down.

- Isolated showers and storms possible along the front this evening.

DISCUSSION

Issued at 241 AM CDT Fri Jul 17 2026

The main feature driving our weather impacts over the next day will be the front across the Dakotas. Ahead of this front will be mainly southerly flow which will have two impacts, one good and one bad. The good impact is that it will transport the smoke away from us as the fire sources are to the north of us. The bad will be that this WAA will keep today quite hot. For this reason the Extreme Heat Warning for the Twin Cities metro continues and a Heat Advisory was issued across much of Minnesota. This is tied more to WBGT values rather than the heat index. WBGT takes other fields like wind, cloud cover, and sun angle into account past the simpler temperature and humidity used in heat index. WBGT values are forecast to be in the 85 to 88 range which suggests that heat stress can occur with work in the sun after 30 minutes. So if you are a sensitive population (old, young, or sick) avoiding work outside is best and if you are not a sensitive population make sure to take frequent breaks in a cool place and drink plenty of water. This will all change as the cold front advances to the southeast today. The SPC has given a marginal risk for strong to severe storms today as an unstable environment with marginal shear will be present ahead of this front from east central MN into west central WI. Farther north and west the environment will have less time to destabilize ahead of the frontal passage. This looks to be a isolated wind and hail threat with shear profiles not favorable for tornados. Behind that cold front winds will shift such that some smoke could move back in. HRRR smoke suggests that the greatest risk would be over Wisconsin as the flow behind the front would be more northwest and much of the smoke could miss a large chunk of Minnesota. In addition as this same system moves through the area with the fires there could be some rain to help in reducing the intensity of the wildfires. In summary if the fires continue at a similar strength smoke could return in similar strength for Wisconsin with lighter smoke possible to the west in Minnesota. Parts of Minnesota would be in the main path of the smoke as well, but that is more in WFO Duluth's area, check their forecast information for details in northeast Minnesota.

High pressure moves in with cooler temperatures on Saturday. Still above normal temperatures, but finally having highs in the 80s instead of 90s. For this reason the heat warnings and advisories are set to expire Friday night. This doesn't last long as WAA returns on Sunday sending highs into the upper 80s to lower 90s. Along with this warm up comes the best chance for rain over the next week late Sunday into Monday. A shortwave trough moving through southern Canada will drive this next round. With this track there remains spread in ensemble guidance in how far south and west PoPs should go. It remains up north closer to the international border where chances are more consistent. What is consistent though is much cooler air advecting in behind this system. This will bring near to below normal temperatures from Tuesday through the end of the week.

AVIATION /18Z TAFS THROUGH 00Z SUNDAY/

Issued at 1250 PM CDT Fri Jul 17 2026

Visible satellite and surface observations depict a surface front northwest of AXN. The front is progged to translate southeast through tonight and will result in a wind shift from SW to NW at each terminal. Ahead of the front, diurnal gusts may approach 20kts. Capping should limit coverage of convection as the front moves southeast, however guidance continues to favor far eastern MN & western WI for the best chance of a few isolated storms. Maintained PROB30s at RNH/EAU and converted them to include a thunder mention. Additionally, surface observations along the front indicate a narrow plume of wildfire smoke settling in behind the frontal passage. While confidence in the degree of visibility reductions due to smoke is low, I wanted to make some smoke mention in the new TAF package and opted to include 6SM FU at all area terminals based on latest hi-res timing.

KMSP...Couple notes to pass along with the new 18z TAF:

1) Should see some showers/isolated storms develop across western WI near or after sunset. Hi-res guidance has continued to suggest the highest probabilities exist east of MSP, so have opted to keep the TAF dry. If showers or storms were to develop, the 2z-4z period seems most favorable.

2) The return of wildfire smoke remains somewhat of a lower confidence forecast, however the latest messaging from MPCA & short term forecast models advertise a narrow plume of VFR smoke impacting the terminal following the frontal passage. Guidance features a secondary push of a higher concentration of wildfire smoke after 15z Saturday, so did include a drop to MVFR visibility.

/OUTLOOK FOR KMSP/ SUN...VFR. Chc MVFR/-TSRA PM. Wind S 10-15 kts. MON...VFR. Chc MVFR/-RA AM, -TSRA PM. Wind SW-NW 10-15G25 kts. TUE...VFR. Wind NW 10-15G25kts.

MPX WATCHES/WARNINGS/ADVISORIES

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