textproduct: Twin Cities

KEY MESSAGES

- Isolated diurnal showers possible Friday. Otherwise the rest of the next 7 days looks dry.

- Long duration, potentially significant heat wave moves in this weekend and continues through most of next week.

DISCUSSION

Issued at 433 AM CDT Thu Jul 9 2026

It has been a quiet night with the diffuse cold front that moved through Wednesday now down across northern Iowa and southern WI. You can also see drying and subsidence on water vapor. Though this looks like a good candidate for fog and stratus, we've hung on to a 3k to 6k foo cloud deck that has kept the fog from running wild this morning. All in all, this will be a very nice day, with skies clearing out and highs in the low 80s with dewpoints retreating to the upper 50s to mid 60s.

As we go through the day today, a weak cold front will be moving across NoDak. Storms will likely fire along the front late in the day today, with a few showers/storm moving into northwest MN and possibly northwest sections of our forecast area out near Alexandria and Long Prairie late tonight. This diffuse boundary will continue east into MN on Friday, where it will start washing out. However, just enough convergence looks to be left over on this front, that when combined with daytime heating will be enough to spark some isolated showers and storms Friday afternoon, most likely in central MN. This is the one straw we have to grasp at for precipitation chances over the next 7 days.

For this weekend, the well advertised and potentially record breaking h5 high begins building in. Those height rises Saturday and Sunday will squash any precipitation chances and begin sending thermometers up into the 90s. By Monday and Tuesday next week, even ensemble means show h5 heights exceeding 600dm in southern MN. In the STC/MPX upper air climate record (1948-present), the max observed h5 height is 598dm. The last time we got there was August of 2023 when the high was...98 degrees. So this will be a hot airmass that builds in next week, just how hot is still uncertain, especially as the h5 heights start to recede Wednesday. However, current soil moisture conditions are not bone dry thanks to recent frequent rains. In addition, we're now entering the peak evapotranspiration season for the corn crop (welcome to corn sweat season!). These two factors will likely make it tough to reach the heights of the top end ensemble members (highs of 100 to 105), but it will still be uncomfortably warm. As for when we'll see relief from the heat, both the GEFS and EPS mean highs for Wednesday-Friday have been trending warmer, so unless we can manage to work some convective complexes this far south mid-late next week (which looks hard to do given our capping and how far north the storm track recedes), which means we're probably looking at the weekend of the 18th and 19th before we start seeing some relief from the heat. See the climate section below for a cautionary note about all those 100s you see models (looking at you ECMWF) cranking out next week.

AVIATION /12Z TAFS THROUGH 18Z FRIDAY/

Issued at 554 AM CDT Thu Jul 9 2026

Lingering fog and lower level clouds will dissipate within an hour or two of TAF start, as temperatures warming even a couple degrees will lose saturation. In addition, there is some dry air incoming from the northwest aloft that will help the entire profile dry out. Winds will remain light and somewhat variable throughout, favoring a northerly component more often than others. As soon as the early fog/clouds are gone, VFR is expected for the rest of the period with mainly high clouds, as forecast soundings highlight a lack of a saturated layer for cumulus development this afternoon.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/

SAT...VFR. Wind S 5-10kts. SUN...VFR. Wind SW 5-10kts. MON...VFR. Wind SW 5-10kts.

CLIMATE

Issued at 433 AM CDT Thu Jul 9 2026

With the heat dome building in, we're seeing many a model and ensemble members throw 100s around for highs like it's no big deal. However, we're going to just put a word of caution about putting 100 in the forecast based on 100 degree climatology in the Twin Cities. The official Twin Cities climate record going back to 1871. In those 155 years, we have met or exceeded 100 degrees only 67 times, with only 6 of those coming since 2000. In the last 50 years multiple 100 degree days in a year has happened only twice, 1988 (4 days) and 2012 (2 days). With it's 00z run, the ECMWF cranked out highs of 99, 100, 101, 105, 103, and 100 for Monday through Saturday next week. This would be something we have only observed once, in 1936. Given how rare 100 degree days are, especially if you ignore what happened during the dust bowl in the 1930s (I really wonder how people survived summers in the 1930s without AC, the heat was absolutely brutal that decade!), we're skeptical about some of the high end forecasts (like that of the 00z ECMWF). With that said, we will likely see several days with highs above freezing, with this level of heat being dangerous for anyone that has to be out working in it.

MPX WATCHES/WARNINGS/ADVISORIES

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