textproduct: Twin Cities

KEY MESSAGES

- Scattered showers and isolated thunderstorms this afternoon into tomorrow morning.

- Next round of rain arrives on Wednesday.

- Generally cooler than normal temperatures this week.

DISCUSSION

Issued at 241 AM CDT Mon Jun 15 2026

The driver of our weather pattern this week will be an upper low over the Hudson Bay in Canada. Shortwaves will moves around this larger low and into the Upper Midwest today and again on Wednesday. Today could well be our warmest day of the week as we get a short break from northwest flow aloft ahead the arrival of the shortwave. The brief period of WAA will not make today a hot day, but it should be near normal (highs in the upper 70s). This slight change in pattern will not have much of an impact on moisture though and that will continue to be a challenge to overcome for rain chances today. The lift from the shortwave and enough mid level moisture will lead to rain formation. There is some elevated instability such that some isolated storms could form. The overall instability profile in forecast soundings is not impressive though, so strong storms are unlikely. Scattered showers and isolated thunderstorms will start to form in central Minnesota this afternoon slowly spreading southeast into the evening and possibly linger in western Wisconsin into tomorrow morning before moving out. We will have a short break on Tuesday during the day between the two waves. The next shortwave moves in Tuesday night into Wednesday. This entire setup looks like a warm season version of a classic winter clipper. The low track is the same setup and the forecast soundings look very similar, just about 30 to 50 degrees warmer. There remains widespread ensemble agreement in this system overall, however like many winter clippers the path will be important. Current mean ensemble tracks favor the low traveling right over southern Minnesota. So this track keeps all of the area well within the rainfall region of this clipper like system. Best chances for rain within the LREF (GEFS, EPS, GEPS) favors along and south of I-94 due to the mean low track among these members. Looking towards thunderstorm chances for this system there is little instability. As mentioned earlier this is a winter like saturated through the profile with only limited and very skinny CAPE present in forecast soundings. However ahead of the low where southerly surface winds will be present there will be ample shear and a nicely curved hodograph. If instability can over-perform expectations this could be something to watch. This does not appear likely though as only the 95th percentile in the LREF shows any significant instability.

Past Wednesday there is a much greater spread among the global ensembles (LREF). The GEFS members in general take a cooler approach and the ENS and GEPS a warmer one. As far as rain is concerned there is some clustering on Friday associated with an expected frontal passage, but past that QPF remains quite scattered with no significant agreement. This does not mean dry though as most members show activity in the weekend period just with different timing and QPF amounts. Safe to say the forecast remains undetermined for this period. This is why the NBM forecast for this period has low PoPs over a wide range of time. As we get closer this should come into better agreement within the LREF and NBM membership.

AVIATION /12Z TAFS THROUGH 18Z TUESDAY/

Issued at 630 AM CDT Mon Jun 15 2026

Quiet weather conditions will persist through the first portion of the 12z TAF period. Light morning winds will gust between 20-25kts out of the west today, prior to the arrival of scattered showers. Initial showers will move into western MN late this afternoon and may have enough instability to produce isolated thunder. Opted to include -TSRA mention in the going PROB30s at AXN/RWF. Instability appears to be weaker farther to the east, so maintained going PROB30s for showers at remaining TAF sites. There may be two waves of showers this evening into the overnight. The second round will be tied to the passage of a surface low across eastern MN/western WI and may bring a period of MVFR cigs prior to daybreak.

KMSP...Best chance for thunder would be in the 2-4z period, but confidence remains too low to include mention in the PROB30. Have opted to message the potential for a heavier rain showers with MVFR visibility during the 2-6z period, followed by a better chance to prevail with VFR showers/MVFR ceilings between 6-10z.

/OUTLOOK FOR KMSP/ WED...MVFR/SHRA likely, chc -TSRA/IFR. Wind SE 5-15kts. THU...MVFR/-SHRA early, then VFR. Wind NW 5-10G20kts. FRI...VFR. Wind WNW 5-15kts.

MPX WATCHES/WARNINGS/ADVISORIES

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