textproduct: Twin Cities

KEY MESSAGES

- Scattered showers and thunderstorms are likely across central MN and western WI today.

- A major pattern shift will occur this weekend. Extreme heat and humidity are expected to build Sunday into next week. Highs in the mid to upper 90s and dew points in the 70s will send heat indices to dangerous levels Monday.

DISCUSSION

Issued at 259 AM CDT Wed Jun 24 2026

Areas of dense fog have developed early this morning on the southern fringes of low stratus across central MN into west central WI. Winds will shift west and increase during the next few hours across western MN, which should bring improving conditions. The stratus is retreating back to the north farther east across east central MN. This may allow for fog to become more widespread with time, but it remains localized enough for now that a Dense Fog Advisory is not yet necessary.

Cyclonic flow will continue shower and thunderstorm chances today east of the Mississippi River. Coverage will be highest in WI and northern and central MN where the boundary layer will remain moist and CAPE builds up to 300-500 J/kg. Profiles are drier across southern and western MN with an inversion around 700 mb. Those factors should keep any showers or storms from forming.

PoPs have been dropped from Friday and Saturday. Southeast surface flow will keep a relatively dry airmass in place and a warm front will remain south across the Mid MS Valley to central Plains. The warm front will approach Saturday night. A strengthening LLJ and rapid moisture increase with steepening mid level lapse rates and sufficient deep layer shear will result in increasing thunderstorm chances. Those storms may linger into Sunday morning before the warm front lifts north.

The passage of the warm front Sunday will result in a major pattern change next week. A stout EML and very warm temperatures aloft (+16C or warmer at 700 mb) will essentially provide an impossible cap to break in the warm sector Sunday afternoon into Monday. PoPs have been reduced some, but may need to be reduced more in coming forecasts. Progged temperatures have increased Sunday and Monday. Depending on the timing of the front and the decrease of convective activity early in the day, highs Sunday may reach the mid 90s across southern and western MN. By Monday, thermal ridging characterized by 925 mb temps of +29 to +32C appear likely to engulf much of central and southern MN and western WI. This is an increase over yesterday by 1 to 2C. Highs in the upper 90s to lower 100s can be expected with this type of airmass. All deterministic guidance now bring highs nearing 100 across southern and western MN, including the Twin Cities. In addition, dew points will rise into the low to mid 70s, especially across eastern MN and WI, potentially pushing heat indices into the mid 100s. Deeper mixing across western MN and a more arid climate in general should allow dew points to fall several degrees short of those levels, but that may also allow temperatures to climb even higher. In fact, guidance indicates 925 mb temps near the SD border as hot as +34C, which would support highs in the mid 100s. Monday is expected to be the first dangerous day for heat of the season, but may only be one of many next week.

Guidance has been consistent with bringing a weakening cold front into western MN Monday evening. The cap should ease as the EML weakens and exits to the northeast late in the day. Rich theta-e air will provide a very unstable airmass. Severe thunderstorm development is possible well into Monday night. The front may lay out across the area Tuesday as the western trough orphans it as it lifts north into Canada. A persistent LLJ from the central Plains to IA may allow renewed development along the front through Tuesday. High pwats around 2 inches and an unstable atmosphere may continue the severe and heavy rainfall threats. Temperatures Tuesday are of lower confidence and will be heavily dependent on convective evolution and residual outflow boundaries.

The rest of next week will feature an intense mid level ridge parked over the mid and lower MS River Valley area. At this range, this could mean a ring-of-fire scenario with multiple severe episodes as shortwaves lift northeast from the Plains around the ridge and/or hazardous heat for the Upper Midwest. In the absence of early day convection, we can expect to tally several 90+ degree days.

AVIATION /12Z TAFS THROUGH 18Z THURSDAY/

Issued at 607 AM CDT Wed Jun 24 2026

IFR/MVFR stratus that had been widespread across central MN for much of the overnight is advancing south with an outflow boundary from overnight storms to the north. Clouds have cleared AXN and STC and finally reached to MSP. This cloud bank will lift and scatter mid morning. Scattered storms will develop east of STC and MSP later today.

KMSP...It's been a challenging TAF overnight, but with the arrival of the MVFR/IFR clouds from the north the dense fog risk has ended. Clearing should take place between 14-15Z, with VFR expected thereafter. Storms are expected to remain east today.

/OUTLOOK FOR KMSP/ THU...VFR. Wind NW 5-10 kts becoming NE. FRI...VFR. Wind SE 5-10 kts. SAT...VFR. Wind SE 10-15kts gusting to 25kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None.