textproduct: Twin Cities

KEY MESSAGES

- Scattered showers and thunderstorms continue across central MN and western WI this evening.

- 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 353 PM CDT Wed Jun 24 2026

A broad 1014mb low associated with a weakening occluded front stretches from north-central Minnesota into the northwestern majority of Wisconsin. Scattered thunderstorms will continue within the cyclonic flow where enough moisture is present. A number of these storms have exhibited at least somewhat organized updrafts, producing hail just under or near the size of a quarter. Latest mesoanalysis as of 3:30pm shows about 1000 J/kg of CAPE and mid- level lapse rates around 6C/km. The main limiting factor for severe weather this afternoon is the low-end 20 to 30 kts of effective bulk shear up in our area. Better shear is further into central and southern Wisconsin, which is why the Severe Thunderstorm Watch has been limited to that region. We may see additional showers or weak storms advect south from northern Minnesota later this evening, but the trend has favored most places remaining dry after these storms push east across Wisconsin.

The mid-level trough shifts east tomorrow, resulting in a quiet weather day for most of the Upper MS Valley with partly cloudy skies and highs in the mid 70s. Widespread storm chances do not increase until Saturday night as a warm front approaches from the south, increasing moisture transport while the LLJ strengthens. Depending on the evolution of the upper trough and associated warm front, the severe weather risk for hail and wind may need to be expanded east into portions of southwestern Minnesota.

Not much has changed in regards to the long term outlook. A major pattern change remains on deck with persistent southwest flow setting up by late Sunday. This will be our first real threat for extreme heat as thermal ridging builds over much of the region. Temperatures around +26 to +32C at 925 hPa combined with dewpoints in the 60s and 70s throughout the week would push heat indices into the low to mid 100s. It is very likely we will need to increase dangerous heat messaging heading into next week, especially on Monday where WBGT are forecasted to reach the mid 80s at many locations. The other factor to keep in mind with heat risk is the amount of relief you are able to get overnight. Lows each day next week look very similar to what our highs have been this week. Phew. As I type that out, I think that is the best way to put into perspective just how warm we are expected to get. The main limiting factor to temperatures would be any overnight or early morning convection, which could drastically lower any heat risk on a given day. That will be the main thing to watch as we head into next week.

AVIATION /18Z TAFS THROUGH 00Z FRIDAY/

Issued at 1200 PM CDT Wed Jun 24 2026

A diurnally driven cumulus field continues to develop and move E/SE this afternoon, creating widespread low end VFR cigs. Some lingering clouds around 2000 ft may lead to occasional MVFR conditions, especially for AXN and STC. Scattered storms are developing in portions of northwest MN and western WI, and will continue to impact the region through the rest of the afternoon. Expect heavy rain and potentially small hail with the strongest storms. A deck of low-level stratus may form over northern MN and northern WI overnight around 1000-2000 ft. Confidence is low on how far south it will spread, but EAU and RNH are most likely to see impacts from that, starting around 10-12z.

Winds will shift from W/NW to N/NE by tomorrow morning for most sites. A few gusts to around 20kts are expected this afternoon for areas in Minnesota, especially across the southwest portion of the state.

KMSP...All of the storms should stay east of KMSP today, but worst case scenario would be having a storm develop overhead during the afternoon and then quickly move east before it matures. Otherwise, VFR conditions expected for the majority of the period.

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

MPX WATCHES/WARNINGS/ADVISORIES

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