textproduct: Twin Cities

KEY MESSAGES

- Scattered thunderstorms develop this evening across southwest to central MN, spreading into southeast MN western WI overnight into Monday AM.

- Summer-like warm through Thursday. Tuesday is forecast to be the warmest day with highs in the low 90s possible.

DISCUSSION

Issued at 157 PM CDT Sun May 24 2026

A pleasant afternoon is underway across much of the Upper Midwest. Temperatures have warmed into the 70s and 80s with mostly sunny skies & relatively light wind. One cannot draw up a much nicer late May day. Unfortunately, all good things must come to an end and today's nice weather is not different. There will be scattered thunderstorms that develop this evening across portions of west and southwest Minnesota. A few of these storms could become strong to severe capable of producing large hail and damaging winds. SPC expanded their level 1 (Marginal) and added a level 2 (Slight) risk areas across SW/WC MN for this evening's severe threat. Forecast soundings reveal 1000-1500 J/kg MLCAPE, sufficient wind shear, and modest forcing that will arrive prior to sunset. Low level lapse rates will be steep given with an inverted V sounding present. This will cause some updrafts to strengthen and produce large hail and possibly gusty winds. Low level moisture is modest - dew points struggle to get into the upper 50s but better mid-level moisture will be enough to get over the hump. The most favorable corridor appears to be along the MN river valley south to the I-90 corridor. A few storms will hold on to clip E MN and W WI overnight, but severe potential wanes by midnight.

For Memorial Day, dry conditions are expected behind the lingering overnight convection. Skies should clear up nicely by mid-late morning. Temperatures will climb further as southerly winds ramp up. High temperatures push into the upper 80s with dew points in the lower 60s. Latest guidance supports a broad area of 2000+ J/kg MLCAPE overhead by Monday afternoon. If we take a few forecast soundings across MN and W WI, they all reveal a mostly capped environment under rising heights. The missing ingredient is any meaningful forcing aloft - something key to overcoming that low level capping. If a storm could form, hail would be the primary concern.

For Tuesday/Wednesday, models show surface dewpoints climbing into the 60s, with PWATs increasing to around 150% of normal. Temperatures will warm further, into the upper 80s to lower 90s, it looks like diurnal destabilization may be enough to break through capping in the afternoon hours. This should lead to isolated pulse thunderstorms capable of producing isolated damaging wind gusts. Forecast soundings support a limited threat of severe weather. Looking ahead into next weekend, we'll be under the heart of an omega block. Surface wise, we'll be west of high pressure over the Great Lakes that drops down from Hudson Bay. This will result in a prolonged period of cooler, dry easterly winds. This will help push highs back down to more normal values, into the 70s, but also dry our the surface low level moisture. Needless to say, with an airmass this dry moving in, it will be difficult to see any precipitation. Long range guidance would hint that a warmer than normal & drier than normal pattern sets up for the first half of Summer.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 639 PM CDT Sun May 24 2026

VFR for all TAF sites to start but a few clusters of TSRA have developed in response to afternoon heating and peak instability of the day. Some of these may make a run for RWF-MKT-MSP going into the early evening hours, producing brief MVFR or IFR conditions. 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...Will monitor radar to see if ongoing convection at initialization looks to reach MSP but have included a TEMPO to account for this activity as it will be fairly close. Otherwise, have maintained the same timing for the overnight convection, 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.

/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.