textproduct: Twin Cities

KEY MESSAGES

- The prolonged heat wave continues this weekend. Extreme Heat Warnings and Heat Advisories have been posted through Sunday evening. The hottest day will be Sunday when heat indices will reach 100 to 110.

- Less humid air arrives Monday, but highs will remain in the mid 80s to low 90s next week.

- Low confidence persists on convective development through Sunday night due to capping and scattered/disorganized nature of storms.

UPDATE

Issued at 809 PM CDT Sat Jul 25 2026

As we approached 8pm, SPC coordinated a Severe Thunderstorm Watch that's valid until 2am for south central MN. This is for what to this point has been a weakly organized cluster of storms approaching Sioux Falls. The CAMs have been on the struggle bus with just getting these storms going, but the 23z and 00z HRRR looked to have finally done a half-way decent job of initiating some storms, with an MCS eventually ending up down in central IL Sunday morning. Based on h85-h3 winds out of the northwest and a reservoir of 6000-8000 j/kg of muCAPE down in northern Iowa, the current thinking is that these storms will lean deeper into Iowa with time, following the steering flow and leaning into the richer instability. There's quite a bit of uncertainty with how far north we will see storms as the LLJ tries to force some convection. If we are to see storms north of the watch though, they would be elevated, with a lower severe risk than what we'll see if we have an organized MCS move across the Iowa border.

Finally, for tomorrow, we'll have to watch how much cloud cover gets left over from storms tonight. If there isn't much, the airmass coming in set all-time record highs Saturday out in Rapid City, so we could be see most of our MN area make a strong attempt at hitting 100. However, as we saw today in eastern MN and western WI, if clouds end up persistent, then we would go the other way and struggle to hit 90. So there's still a good deal of uncertainty for highs Sunday, but that high end potential is a bit concerning .

DISCUSSION

Issued at 252 PM CDT Sat Jul 25 2026

EXTREME HEAT...The main axis of the heat ridge will remain over the Rockies through the weekend into early next week. However, surface fronts will maintain the extensive warm sector across the WFO MPX coverage area, including elevated low-mid level moisture advection, through the weekend. This means not just the daytime hours with highs in the low-mid 90s today and into the mid-upper 90s Sunday but also overnight lows mainly in the low- mid 70s tonight and Sunday night. With dewpoints into the upper 60s to mid 70s (even upper 70s tomorrow), this will prolong dangerous heat conditions through Sunday night, hence the expansion of the Extreme Heat Warning from much of our MN area to the remainder of our area tonight into tomorrow. Sunday will be by far the hottest day with HI's for nearly our entire area reaching 105-110 and WBGT's climbing into the upper 80s for the vast majority of our area. The heat ridge will retreat westward for early next week while a weak frontal boundary drops south, which will allow dewpoints to drop off appreciably, back to the 60s to near 70 for the rest of the week while gradually fall back to the upper 80s to lower 90s. So, not to say it won't at all be warm/humid depending on location within our 51 counties, but it will not be nearly as hot/muggy as today through Sunday.

THUNDERSTORM POTENTIAL...Quite the tricky and low confidence forecast when it comes to the where/when of any convection which may develop over the WFO MPX coverage area. Quiet thus far today, not only over our area but also upstream over the eastern Dakotas. Starting to see some development over western SD in response to strong surface heating and modest to steep lapse rates and inherent instability. 12z RAOBs and model soundings still show plenty of mid-level capping with warm H85-H7 temperatures that seem to be diminished in pockets, similar to where there are spots of stronger surface heating than others. The idea is that storms will blossom over eastern SD and drift ESE into southwestern MN later this afternoon through this evening. However, only a few CAMs indicate such idea, and even fewer run-to-run today. Some CAMs indicate no convection at all. So this is a highly conditional setup for today due to the strong low-mid level capping (indicative per the continual low level stratus today) and the patchwork of integrating higher instability, plus with fairly unimpressive dynamics aloft.

Once past tonight's potential convection (and there is even the idea among a few CAMs of a sunrise-ish complex over eastern MN into western WI, so still plenty of uncertainty), then there looks to be a better organization Sunday afternoon-evening despite continued wide-ranging model solutions. More NW flow aloft may allow a few disturbances to rush through the area, especially within the higher temp/dewpoint regime leading to steep lapse rates and poorer capping with a weak frontal boundary dropping south. Still rather disorganized in nature, there may be a few clusters of storms late day into the evening with the main "target" area as far western into far southern MN.

MONDAY ONWARD...A more tranquil pattern looks to settle in starting on Monday with drier air and a slow drop of temperatures as the week progresses. Overall, highs will return to the mid 80s to lower 90s as a general range throughout the week while dewpoints fall back to the 60s to near 70 during the daytime hours. It is possible that the TC metro may need a Heat Advisory on Monday but otherwise the forecast does not seem to support any additional heat headlines beyond the weekend. More pronounced northwest flow aloft will prevail throughout the week with the occasional disturbance drifting through the Upper Midwest. No appreciable surface boundaries are expected for our region, which will limit any chances for precipitation due to the lack of forcing and lack of low level convergence features. The best chance after this weekend looks to come late Thursday through early Friday, mainly owing to a fairly well-defined shortwave trough aloft expected to move through the region. Nothing impressive nor any surface features, but a swath of deeper moisture accompanying the trough looks to produce scattered showers/thunderstorms for late Thu into Fri.

AVIATION /00Z TAFS THROUGH 06Z SUNDAY/

Issued at 650 PM CDT Sat Jul 25 2026

Fairly quiet start to the 00z TAF window as the primary near term concern is lingering MVFR Cu across southeastern MN and western WI. Latest obs show that Cu has scattered out at MKT/MSP/RNH, but remains at EAU. Attention turns back to the west where severe storms have fired across South Dakota. General consensus across the guidance suite is that some flavor of convective complex will move across southwestern MN and turn towards northern IA tonight. We've opted to introduce PROB30's at RWF & MKT where the highest probabilities for storms exist across the hi-res guidance. In addition to the storm chances at the southern terminals, we will also monitor potential visibility reductions at the western WI terminals due to ground fog. The slow to clear Cu has introduced some doubt in the degree of clearing across western WI, which adds uncertainty into widespread fog will be. That said, followed LAMP trends and introduced TEMPOs for visibility reductions before/through daybreak. Southerly winds increase to between 5-10kts tomorrow. Scattered storms are possible tomorrow afternoon and evening, but confidence in coverage is low. Forthcoming TAFs may need the introduction of convective probs.

KMSP...Main focus heading into tonight will be the eastward track of storms moving across South Dakota. Latest hi-res guidance keeps the storms well to the south and west of the terminal. With a strong cap aloft, with will maintain a dry 00z TAF, but it's plausible that a shower or storm could develop late tonight. Additional storm chances are possible tomorrow, mainly across western WI. Once again, we'll keep the TAF dry for now, but further refinements may be needed.

/OUTLOOK FOR KMSP/ MON...VFR. NW at 10-15G25kts. TUE...VFR. Wind N 5-10 kts. WED...VFR. Wind SE 5-10 kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...Heat Advisory until 2 AM CDT Sunday for Benton-Chisago-Douglas- Goodhue-Isanti-Kanabec-Mille Lacs-Morrison-Sherburne- Stearns-Todd. Extreme Heat Warning from 11 AM to 9 PM CDT Sunday for Anoka- Benton-Blue Earth-Brown-Carver-Chippewa-Chisago-Dakota- Douglas-Faribault-Freeborn-Goodhue-Hennepin-Isanti- Kanabec-Kandiyohi-Lac Qui Parle-Le Sueur-Martin-McLeod- Meeker-Mille Lacs-Morrison-Nicollet-Pope-Ramsey-Redwood- Renville-Rice-Scott-Sherburne-Sibley-Stearns-Steele- Stevens-Swift-Todd-Waseca-Washington-Watonwan-Wright- Yellow Medicine. Extreme Heat Warning until 2 AM CDT Sunday for Anoka-Blue Earth-Brown-Carver-Chippewa-Dakota-Faribault-Freeborn- Hennepin-Kandiyohi-Lac Qui Parle-Le Sueur-Martin-McLeod- Meeker-Nicollet-Pope-Ramsey-Redwood-Renville-Rice-Scott- Sibley-Steele-Stevens-Swift-Waseca-Washington-Watonwan- Wright-Yellow Medicine. WI...Heat Advisory until 2 AM CDT Sunday for Pierce-Polk-St. Croix. Extreme Heat Warning from 11 AM to 9 PM CDT Sunday for Barron- Chippewa-Dunn-Eau Claire-Pepin-Pierce-Polk-Rusk-St. Croix.