textproduct: Twin Cities

KEY MESSAGES

- Smoke continues to linger across far eastern Minnesota and Wisconsin into Monday. See Air Quality Alert for more information.

- Thunderstorms likely tonight and early Monday. A few storms may be strong or severe.

- A short period of hazardous heat and humidity Monday afternoon before turning cooler for midweek.

- Hot temperatures return next weekend.

DISCUSSION

Issued at 331 PM CDT Sun Jul 19 2026

Visibilities are improving slowly this afternoon as surface smoke density decreases. The worst visibility remaining is Eau Claire with less than 3 miles. The smokey haze will continue through tonight as the reservoir of smoke continues to drift to the north and east around high pressure centered on the Great Lakes. The smoke will primarily impact far eastern MN and WI where an Air Quality Alert is in effect through Monday morning.

The atmosphere is stable this afternoon, but low level moisture is increasing across the eastern Dakotas. An upper trough will approach tonight and moisture advection will spread east. Clusters of thunderstorms are expected to develop across the Dakotas this evening. As the base of the trough begins to arrive, the mid level jet will strengthen to 50+ kts resulting in more than enough bulk shear. Steep lapse rates will work east across the Plains overnight. An increasing LLJ will feed the clusters/MCS as it continues southeast. CAMs remain supportive of this activity tracking across central and eastern Minnesota into western Wisconsin late tonight and early Monday morning. The main severe risk is damaging wind. The degree of this threat will depend on the strength of capping and whether any organized cold pools can develop. There is a level 1 of 5 risk for the entire CWA.

The morning activity should clear to the southeast early enough to allow recovery to occur throughout the day. The surface cold front will be located from northwest WI to southwest MN around midday. Dew point pooling with the front and quick heating following the morning storms as a thermal ridge overspreads the region will bring a short period of hazardous heat during the afternoon. Dew points may rise into the upper 70s across southern MN, bringing heat indices to the 100-105 degree range. Farther north with the earlier passage of the cold front, dew points will peak early afternoon before drier air follows. Thermal ridging will remain in place through the afternoon, and given better boundary layer mixing behind the front, temperatures will rise more easily. Therefore, heat indices in the metro area may peak early afternoon, then hold steady or slowly fall for the rest of the afternoon while air temperatures rise into the low to mid 90s. As for thunderstorm redevelopment later in the day, the front should clear most of the CWA before initiation occurs. There is a small chance a few storms fire in a corridor from Albert Lea to Rice Lake and Eau Claire late afternoon, but the better bet is across IA into central WI.

Cooler and less humid air returns by midweek. Highs in the upper 70s to low 80s and lows in the 50s or 60s will bring much needed relief from the recent heat. Ridging will return to the central U.S. next weekend. The Upper Midwest will be on the northern periphery this time instead of directly beneath it, so this may begin a more active convective pattern heading into next week. There will be some very hot air over the Plains that should occasionally move in. Highs by Sunday may be solidly in the 90s.

AVIATION /18Z TAFS THROUGH 00Z TUESDAY/

Issued at 1240 PM CDT Sun Jul 19 2026

Visibility reductions due to wildfire smoke continue to impact RNH & EAU to open the 18z period. Followed hi-res & observational trends to take a more optimistic approach in removing smoke from RNH early in the period. On the flip side, it looks like smoke will linger through at least the early evening at EAU. Next item of note is growing confidence in a round of thunderstorms at all terminals tonight. Followed HREF/REFS clustering trends in upgrading PROB30s to TEMPOs at most sites and also made slight timing adjustments. The passage of a cold front will end convective chances Monday morning and winds will turn westerly towards the end of the period.

KMSP...Few more hours of VFR smoke, then a quiet stretch with high clouds and southerly surface flow. We wanted to message increasing confidence in a round of convection overnight, so upgraded the PROB30 to a TEMPO for 2SM TSRA between 8-11z. Storms should be fairly progressive and will be followed by a cold frontal passage and associated wind shift to out of the WNW through the day.

/OUTLOOK FOR KMSP/ TUE...VFR. Wind NW 10-15G25 kts. WED...VFR. Wind N/NW 5 kts. THU...VFR. Wind SW 5-10 kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...Heat Advisory from noon to 6 PM CDT Monday for Anoka-Carver- Dakota-Goodhue-Hennepin-Ramsey-Rice-Scott-Washington. Heat Advisory from noon to 7 PM CDT Monday for Blue Earth- Brown-Faribault-Freeborn-Le Sueur-Martin-Nicollet-Sibley- Steele-Waseca-Watonwan. WI...None.