textproduct: Twin Cities

KEY MESSAGES

- Severe thunderstorms possible late Thursday afternoon & evening.

- Heat & humidity return for Friday into the weekend. Heat Index values around 100 degrees likely.

- Frequent chances for scattered showers & thunderstorms into next week.

DISCUSSION

Issued at 226 PM CDT Wed Sep 2 2026

Tonight: Quiet weather tonight with cloud cover beginning to increase overnight. Patchy fog is possible across southern Minnesota where 1-2: of rain fell last night, most pronounced in valleys & other low-lying areas.

Thursday Morning: A low-level jet over the central plains strengthens overnight, nosing into southern Minnesota & southwest Wisconsin by early tomorrow morning. Scattered showers & thunderstorms are expected to develop on the nose of this jet, with the best chance for some rain expected from southern Minnesota into western Wisconsin. Sporadic wind gusts of 30-40 mph & small hail can't be ruled out with the strongest of these thunderstorms, but the threat for any strong thunderstorms is higher off to our south. High-resolution models still remain widely varied in depicting how theses showers & storms will evolve into tomorrow morning, so confidence remains low on forecasting just how widespread the rain will be & how long it may linger into Thursday morning.

Thursday afternoon/evening: The answer to the above question will play a large role on what kind of potential may develop for thunderstorms later Thursday afternoon & evening. Synoptically, an impressive environment for severe weather will develop over the upper Midwest Thursday as an upper level jet with 50 kts of deep shear develops long the northern tier of the CONUS, while an elevated mixed layer advecting from over the Rockies provides very steep lapse rates around 8 C/km. However we won't have much of surface boundary over the area to initiate storms, so our severe potential will depend greatly on how much instability we can realize by the afternoon. Warm & moist advection through the day will provide the conditions for CAPE values to reach 3000-4000 J/kg - if we're able to remain sunny through the afternoon & warm into the upper 80s to low 90s. It's no surprise that the same high- resolution modes that remain widely varied regarding the showers & thunderstorms tomorrow morning & also widely varied with how they depict the second round of thunderstorms during the afternoon/evening. Generally, the wetter/cloudier solutions hold off any thunderstorms until later in the night when a potential MCS could arrive out of the Dakotas, while the drier solutions are able to develop some discrete storms over central & southern Minnesota by late afternoon.

Confidence is low, but the general trend seems to be towards the showers & cloud cover lingering longer into the morning & afternoon. This does not mean we're done with a severe threat tomorrow evening though, as there are signs that thunderstorms developing closer tot he surface low over the dakotas could congeal into a MCS that eventually propagates through the area later in the evening & night. Damaging wind will be the primary severe threat with any storms that develop, especially if we get the forward-prooapgating MCS out of the Dakotas, while very large hail is possible earlier in the evening with any discrete storms that develop over central/southern Minnesota. Heavy downpours are expected with thunderstorms but they should be moving fast enough to mitigate any heavy rain/flooding concerns.

Friday-This Weekend: Warm advection continues into the weekend with a return to more summer like humidity values, along with temperatures in the upper 80s to low 90s. Excessive heat could become a concerns as Heat Index values approach 100 degrees, but we are still coming off of a very warm July-August so acclimation means we're probably able to push our excessive heat thresholds a little higher than normal. Friday looks to be dry but another chance for isolated to scattered thunderstorms looks likely overnight into early saturday morning. Models remain widely spread in possible precipitation events through the rest of the weekend, so even though our forecast shows 30-40% PoPs, it won't be a washout of a weekend.

Next Week: The upper air pattern remains active as a number of disturbances ride over the ridge centered over the region. Confidence is low on when & where the greatest precipitation chances will be, but there at least appears to be some minor relief coming from our drought. temperatures will depend on the timing of any precipitation systems, but will tend to be above- normal earlier in the week with some cooling relief likely later in the week.

AVIATION /00Z TAFS THROUGH 06Z FRIDAY/

Issued at 620 PM CDT Wed Sep 2 2026

VFR conditions through the overnight with FEW to SCT mid to high level clouds and winds light and VRB, or generally out of the east. High res model guidance continue to show shower/storm activity develop across SW and south-central MN tomorrow morning. This activity will move NE through the morning, bringing possible impacts to RWF/MKT and then MSP/EAU/RNH by 14-15z. Confidence is low regarding thunder potential for MSP and western WI terminals, continued with PROB30 for -SHRA.

Southerly winds increase during the early afternoon hours becoming 7-11 knots with gusts to 17-20 knots possible. Clouds will remain SCT to BKN through the afternoon. Another round of showers/storms will be possible tomorrow evening/overnight. However, this will greatly depend on how widespread and the morning activity could be and how long cloud cover lingers into the afternoon. That said, confidence is low but if storm do develop, they will likely be strong to severe.

KMSP...Chance for SHRA and isolated TSRA through tomorrow morning, most likely between 14-17Z. More concern is with the potential for any strong to severe storms tomorrow evening, but confidence is very low on whether storms will form & where they could track so no mention in TAF.

/OUTLOOK FOR KMSP/ FRI...VFR. Wind S 5-10 kts. SAT...VFR. Chance -TSRA late. Wind SE 5-10 kts. SUN...VFR. Chance -TSRA. Wind SSE 5-10 kts.

MPX WATCHES/WARNINGS/ADVISORIES

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