textproduct: Twin Cities

KEY MESSAGES

- Severe thunderstorms expected tonight, most likely after midnight. Damaging wind is the primary threat, especially across western Minnesota.

- Another round of severe thunderstorms Wednesday. Less certainty on when & where storms will develop. EAstern Minnesota/western Wisconsin during the afternoon has the highest chance for severe thunderstorms.

DISCUSSION

Issued at 1039 AM CDT Tue Jun 9 2026

Today: Low stratus has been slow to dissipate across eastern Minnesota & western Wisconsin this morning, which may lead to slightly cooler temperatures than previously forecast for this afternoon. Still, it's going to be hot & muggy with highs well into the 80s & dewpoints in the 70s leading to heat indices above 90 this afternoon. More interesting to our weather later today is the complex of decaying thunderstorms off to our southeast across Nebraska & South Dakota. The remnant boundaries from these thunderstorms will continue to track northeastwards into southern Minnesota, providing a source of lift for thunderstorms late this afternoon. Our morning weather balloon showed cooler upper level temperatures than expected, meaning the capping inversion this afternoon may be weak enough for thunderstorms to initiate along the old thunderstorm boundaries. A few high- resolution models pick up on this potential, but are widely spread on how the thunderstorms evolve. If thunderstorms are able to initiate late this afternoon, then there is the potential that they become severe & lead to a much earlier severe weather event across southern Minnesota late this afternoon & into this evening. If the capping is able to hold this afternoon, then we'll stay dry into this evening with our attention the turning to the severe thunderstorms expected to develop over the Dakotas this evening.

Tonight: Severe thunderstorms are expected to develop ahead of a cold front across the Dakotas this evening. These storms will eventually merge into a line, or multiple clusters of storms, & eventually move into western Minnesota late tonight (10 PM- midnight). The instability is expected to wane overnight, but we'll still have 1500-2000 J/kg of surface-based CAPE for these storms to work with as they enter western Minnesota. Damaging wind gusts looks to be the main severe weather hazard with the line of storms, but a few quick tornadoes can't be ruled out within the line. How far east the line of thunderstorms & damaging wind threat continues into Minnesota & western Wisconsin is still uncertain given that instability will continue to decreases after midnight & into the overnight hours. However we'll still likely hold onto at least some surface- based CAPE into early Wednesday morning, meaning a threat for damaging winds exists still exists into eastern Minnesota & western Wisconsin. The line of storms looks to be very fast moving with storm motions over 50 mph possible, so timing-wise we're looking at a window of 11 PM-2 AM for western MN, 1 AM-4 AM for eastern MN, & 3 AM-6 AM for western Wisconsin.

Wednesday: The overnight thunderstorms should be out of the area around sunrise, meaning we should see much in the way of remnant precipitation & cloud cover to limit our heating potential Wednesday morning. However how the rest of the day unfolds remains uncertain at this time given the wide range in solutions among high-resolution models. A higer-end environment for severe weather is expected to develop by the afternoon with over 2000 J/kg of surface-based CAPE & 35-40 kts of deep shear over the area, the question is just where storms initially develop & how early in the afternoon. The initial storms that develop look to be supercellular, meaning large hail, damaging winds, along with tornadoes are all possible. Eventually, these supercells will merge & produce multiple clusters or lines of storms, at which point the primary severe hazard becomes damaging wind. Generally, the consensus view is that storms initially develop near the I-35 corridor across eastern Minnesota mid-afternoon, then merge into the clusters/lines of storms across western Wisconsin through the late afternoon/early evening. The SPC outlook highlights that idea with the Enhanced Risk & greatest threat for tornadoes/wind across eastern Minnesota & western Wisconsin. However, if storms are able to develop earlier in the afternoon as a few high- resolution models depict, then these higher probabilities will have to be shifted more to the east. These storms will also be fast moving, meaning the severe threat looks to be over across our area by the evening (8-10 PM). This should also limit the flooding threat as any heavy rain will only fall over a given area for an hour or two.

Thursday: A few models depict another thunderstorm complex clipping southern Minnesota during the morning, but otherwise the severe threat looks to be off to our south & east. A few thunderstorms are possible ahead of the cold front across southeast Minnesota& western Wisconsin, but otherwise we'll see a chance for isolated showers & a few thunderstorms in the cooler airmass behind the front.

Fridai-This Weekend: A much cooler Canadian airmass moves into the region & lingers through the weekend as the heat becomes entrenched over the eastern seaboard. Ensemble guidance shows temperature anomalies near 10 degrees below normal over the weekend & into early next week, meaning we'll see much more comfortable highs in the low to mid 70s & lows in the 40s & 50s. A few chances for precipitation are possible but little or now chance for heavy rain or strong thunderstorms.

AVIATION /00Z TAFS THROUGH 06Z THURSDAY/

Issued at 656 PM CDT Tue Jun 9 2026

VFR to start for all sites with varying mid-to-upper level FEW- SCT coverage. Clouds/precip will develop fairly quickly late this evening into the early morning hours as confidence remains fairly high that an MCS will traverse MN-WI overnight, generally in the 04z-10z timeframe from western TAF sites to eastern TAF sites. Conditions will likely drop to IFR, mainly due to heavy rain with the thunderstorms associated with the overnight system. In addition strong/gusty winds with a sharp directional change is possible as the system moves across any given terminal. Have kept the TS mention to just the TEMPO so as to not thrust a 3-4hr solid TS window at any given site. Conditions will temper down during the pre-dawn hours thru daybreak, with VFR conditions likely for much of the day Wednesday. Another round of thunderstorms looks to develop in far eastern MN late Wednesday afternoon then progress eastward across WI Wednesday evening. This Wednesday system looks to be stronger than the one for tonight, but the Wednesday system looks to impact the WI sites, potentially as far east as MSP.

KMSP...First round of storms looks to move across MSP in the 08z-10z timeframe per decent multi-CAM agreement. Ceilings likely down to MVFR while visibilities drop to IFR-or-lower, depended on rainfall intensity. Gusty winds and frequent lightning are likely to come with the thunderstorms. Tonight's storms are expected to conclude prior to the Wednesday morning push, resulting in VFR conditions through mid-Wednesday afternoon. Another round of storms looks to develop over eastern MN late Wednesday afternoon and slide east. Still some uncertainty as to whether MSP will be impacted, thus have maintained the PROB30. Even if the storms do not directly impact MSP, routes eastward of MSP will be impacted.

/OUTLOOK FOR KMSP/ THU...VFR. -RA likely. Slight chc PM -TSRA. Wind SW 5-10kts becoming W 10-15G25kts. FRI...VFR. Wind W 15G30kts. SAT...VFR. Wind NW 5-10kts.

MPX WATCHES/WARNINGS/ADVISORIES

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