textproduct: Twin Cities

KEY MESSAGES

- Scattered thunderstorms develop this evening from southwest to central MN, spreading into southeast MN western WI through Monday morning.

- Highs in at least the 80s are expected today through Thursday, with Tuesday looking to be the warmest day with highs in the low 90s possible.

DISCUSSION

Issued at 416 AM CDT Sun May 24 2026

A longwave trough axis is working across MN this morning. Immediately behind the trough, light southwest h85 winds develop, with enough WAA to kick off a batch of accas over southwest MN that has been attempting to generate some weak convection overnight. This batch off accas will spread east through the morning, with a continued attempt at convective initiation as it moves east, though those attempts should continue to rarely succeed. Besides this accas, high pressure and light winds have setup excellent conditions for radiational fog across the eastern half of MN. You can see the fog on the nighttime microphysics RGB up by Duluth, but it's hard to spot on satellite in the MPX area. That means the fog down here is very shallow and will mix out quickly with the rising sun this morning. After the morning fog and accas clear out, we'll be left with a very pleasant day, with more sun today allowing highs to punch up into the lower 80s. This will be the first of a few 80+ days we'll be able to string together this week.

Looking at the thunderstorm potential today/tonight, the first thing to note is the SPC all but removed the Marginal Risk from our area in the new Day convective outlook. Thunderstorms this afternoon will develop over eastern Neb, where a weak LLJ will coincide with 2000- 2500 j/kg of mlCAPE. For the MPX area, our precipitation chances don't looking to pick up until closer to and after sunset as this LLJ begins to push northeast into south central MN and eventually western WI. There's lots of spread on exactly where storms develop this evening and how much coverage there will be. However, looking at the HREF mean h85 winds, the weak LLJ tonight is forecast setup from the I-90 corridor in south central MN, up toward the Eau Claire area in western WI. This is where the EPS probabilities for measurable precipitation are the highest. From the severe perspective, the threat for the MPX area looks very low as it looks to be one of those cases where we have enough instability for thunderstorms, but not severe weather, so we're in agreement with the continued trimming of severe probabilities for today/tonight out of the MPX area.

For Memorial Day itself, dry conditions are expected behind the morning LLJ activity as upper heights build in. Temperatures will take another step up on the southerly winds, with the HREF showing mlCAPE values of 2000-2500 j/kg developing as temperatures push into the upper 80s. However, forecast soundings show this being capped and given the rising heights, we don't look to have the forcing to do anything with that instability.

For Tuesday and Wednesday, models show surface dewpoints climbing into the low 60s, with Pwats increasing to around 150% of normal. With temperatures taking a step up into the upper 80s to lower 90s, it looks like diurnal destabilization may be enough to break through capping in the afternoon, with isolated to scattered storms possible each day. Given the weak flow aloft, these would be pulse type storms, with little organization, which means the risk for severe weather will remain low.

For Thursday into next week, we'll be at the center of an omega block at h5 and to the west of high pressure over the Great Lakes that will have dropped down from Hudson Bay. This will result in a prolonged period of easterly winds. This will help push highs back down into the 70s next weekend, but also drop dewpoints possibly all the way down into the 30s. Needless to say, with an airmass this dry moving in, it will be tough to get anymore diurnal activity beyond Wednesday. And looking beyond this forecast and into the extended guidance from the GEFS and ECMWF, it's looking like the theme for June up here will be expanding drought.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 114 PM CDT Sun May 24 2026

VFR for all TAF sites to start with clouds very few and quite far between at initialization time. SKC conditions likely to persist through the daylight hours, potentially aside from some high clouds filtering in from W or SW as a warm front moves into the region. Mid-to-high ceilings are likely from late evening through much of the overnight hours, along with scattered -SHRA for mainly far southern MN into western WI during the overnight hours. A few select hours of TSRA potential is there for most TAF sites, mainly after midnight but prior to sunrise. Visibilities may well drop into MVFR range should any decent rainfall move across any given site but ceilings are expected to remain within VFR range. Skies will then gradually clear out from around sunrise onward on Memorial Day. Winds will remain generally southerly throughout with speeds in the 6-10kt range, potentially a bit higher and gusty during the day tomorrow.

KMSP...Went a little later in the timing of the overnight TAF compared to the 12z TAF, now looking for the window of -SHRA to be in the 05z-10z range, with TSRA roughly 07z-10z. CAMs are still relatively all over the place with the location/timing of overnight convection so this timing may shift a bit yet in upcoming TAF issuances. Otherwise, the idea of VFR ceilings with possibly MVFR visibility during convection still holds for MSP.

/OUTLOOK FOR KMSP/ TUE...VFR. Wind SSW 5-10kts. WED...VFR with P.M. MVFR/-TSRA possible. Wind SE 5-10 kts. THU...VFR. Wind SE 5-10 kts.

MPX WATCHES/WARNINGS/ADVISORIES

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