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 /00Z TAFS THROUGH 06Z THURSDAY/

Issued at 622 PM CDT Wed Jun 24 2026

Additional thunderstorms are not expected to impact any terminals in this period. We will likely see another round of low stratus move in across the central Minnesota and northwest Wisconsin in the early morning. How far this spreads south is currently the question. So aimed for a middle ground in the 00Z TAFs. It could go as far south as impacting everywhere but MKT. This low stratus deck would be IFR. There is also an area of IFR to maybe LIFR fog associated with this same airmass. Currently this looks to stay north/east of terminals. If the spreading of this airmass does over-perform there could be IFR ceilings and visibility during the morning hours. This will all clear up in the later part of the morning. Winds, after today's gusts end along the usual diurnal curve, will be light and variable.

KMSP... The main impact will be if we can get a repeat of IFR ceilings like we saw this morning. It is similar setup, but with a less moisture so it is not a lock. Went with a SCT IFR ceilings for now, but as we see everything come together with the 06Z TAFs we should be able to have more confidence on if this will occur.

/OUTLOOK FOR KMSP/ FRI...VFR. Wind SE 5-10 kts. SAT...VFR. Wind SE 10-15G25 kts. SUN...MVFR/SHRA Chc TSRA. Wind SE 10-15G30 kts.

MPX WATCHES/WARNINGS/ADVISORIES

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