textproduct: Twin Cities

KEY MESSAGES

- Thunderstorms likely Wednesday morning with a risk for severe wind and hail.

- A second round of storms is expected Wednesday evening, with a level 3/5 risk for severe weather. Winds of 70+ mph possible, along with large hail and a few tornadoes.

- Storms and humidity continue through the weekend, with localized flash flooding possible for areas that see multiple rounds of storms.

DISCUSSION

Issued at 332 PM CDT Tue Jun 30 2026

Visible satellite imagery shows an occluded low spinning over southern Manitoba, with a slow moving cold front extending down from Lake Superior through western WI and into northern IA. Despite having this front move through, temperatures are still warm with widespread 80s and even some spots hitting 90 already this afternoon across eastern MN and western WI. It is not as humid today for areas behind the front, but many locations are still seeing upper 60s or low 70s closer to and ahead of the front. A Heat Advisory remains in effect through 9pm for these locations, with heat indices maxing out around 95-100 degrees.

The front becomes quasi-stationary as it slowly drifts north from Iowa tomorrow. This will shift winds more S/SE-erly and increase moisture transport through the day. PWATs are expected to climb to 1.5-2" by Wednesday evening, setting the stage for more humid conditions to continue throughout the week. Along this boundary and moisture influx, multiple rounds of storms are expected, starting early tomorrow morning. A northeastward propagating MCS is expected to develop along the nose of a strengthening LLJ across Nebraska this evening, which should continue all the way into southern MN and potentially western WI. Adequate shear and instability will be present to support organized convection with a damaging wind and hail risk. Forcing does weaken during the early morning as the storms move into southern MN, so this may limit the overall coverage and risk of severe weather. The most likely timing is between 5-8am for much of MN and between 8-10am for western WI. These storms will be moving quickly, so we are expecting to clear out for the most part by late morning. Filtered sunshine will warm us up into the 80s and allow the atmosphere to destabilize again during the afternoon.

There is growing confidence for a second round of storms to develop along the stationary boundary during the late afternoon into the early evening. Thermo profiles would support both large hail and damaging winds, especially if storms are able to remain discrete during initialization. We expect storm to cluster together as the event unfolds, potentially maturing into a bowing MCS. In this scenario, the damaging wind threat would increase with winds of 70+ mph becoming possible. Storms may not develop until early evening across southwest MN (around 6-8pm) and then may not exit east until late in the night (around 1-2am). The latest SPC Day 2 SWO has been upgraded to a level 3/5 (Enhanced) risk for time period, with an emphasis on a risk for those elevated wind speeds depending on storm mode. This remains a situation where the morning convection will play a role on how the storm threat evolves in the evening, primarily in influencing where the surface boundary sets up.

Storms and humid conditions continue through the week as this quasi-stationary front acts as a fire hose for convection to fire along. WPC's latest 5-day QPF places a broad footprint of 2"+ for much of the southern half of MN and the majority of WI, as well as a bullseye of 5"+ for southeastern MN. As it always does with summertime convection, total rainfall will likely be more sporadic than this forecast, but this highlights the idea that we will continue to have several rounds of storms over a somewhat confined area as long as the boundary does not shift that much over the next few days.

AVIATION /18Z TAFS THROUGH 00Z THURSDAY/

Issued at 1216 PM CDT Tue Jun 30 2026

Mostly clear skies will continue through the start of the period, outside of EAU who will see a chance for isolated to scattered storms in the area this afternoon. Latest trends are for any storms that develop to stay mainly south, though a prob30 is warranted given the proximity.

Winds remain gusty through the evening out of the SW, then shift more S/SE and weaken overnight. There is growing confidence for a cluster of storms to move northeast from Nebraska/Iowa during the early morning, reaching many sites around 12-16z. Introduced a prob30 where storms are most likely. Showers and isolated TSRA may continue after the initial wave of storms, though confidence is too low to include at this issuance.

KMSP...A few low clouds may develop this afternoon, tied to a TSRA chance to south, otherwise VFR conditions will continue until tomorrow morning. The most likely window for TSRA in the morning is between 12-15z, and it would likely last about 2-3 hours. Additional storms and showers are possible after the first wave through about 18z, though they would not be as strong or widespread.

/OUTLOOK FOR KMSP/ WED PM...Chc MVFR and -TSRA. Wind SW 5-10 kts. THU...VFR. Chc PM -TSRA. S 5-10 kts. FRI...VFR. Chc -TSRA. S 5-10 kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...Heat Advisory until 9 PM CDT this evening for Anoka-Blue Earth- Brown-Carver-Chisago-Dakota-Faribault-Freeborn-Goodhue- Hennepin-Le Sueur-Martin-McLeod-Nicollet-Ramsey-Rice- Scott-Sibley-Steele-Waseca-Washington-Watonwan-Wright. WI...Heat Advisory until 9 PM CDT this evening for Barron-Chippewa- Dunn-Eau Claire-Pepin-Pierce-Polk-Rusk-St. Croix.