textproduct: Twin Cities

KEY MESSAGES

- Critical fire weather conditions likely Wednesday across west-central & southwest Minnesota.

- Widespread thunderstorms late Thursday afternoon & evening. The strongest storms could contain damaging wind gusts & large hail.

- Temperatures return to more normal values this weekend, below-normal next week.

DISCUSSION

Issued at 130 PM CDT Tue Apr 21 2026

Not a cloud in the sky across much of the Upper Midwest this afternoon as we're seeing temperatures warm well into the 70s across much of the area. Very dry dewpoints will result in RH values falling below 20% across much of Minnesota, but northerly winds below 10 mph will mitigate any fire weather concerns.

Even warmer temperatures are expected Wednesday as strong southerly flow develops in response to a deepening surface low in the lee of the Northern Rockies. This warm advection along with rising 850 mb temperatures suggest that widespread highs in the 80s are expected across much of Minnesota & Wisconsin, & could reach 90 across southwest Minnesota where the low-level thermal ridge looks to be set up during the late afternoon. Dew points will actually be rising into the 40s & even 50s through the day, but the very warm temperatures, & deep mixing from winds gusting to 30 mph suggests that critical fire weather conditions are likely across southwest Minnesota during the afternoon. Issued a Red Flag Warning for southwest Minnesota & much of west- central Minnesota where the highest fire danger risk is present, meanwhile a Fire Weather watch has been issued farther east & north across Minnesota where winds will be lighter & confidence is lower on how far RH values may drop during the afternoon.

The strong southerly flow continues into Thursday as dew point values continue to rise towards 60 degrees through the afternoon. This will result in a corridor of 1000-1500 J/kg of surface-based CAPE by the afternoon, along with deep shear values of 25-30 kts along a cold front approaching out of the dakotas through the afternoon & evening. Storm initiation will likely have to wait until later in the afternoon when stronger forcing from the upper level trough arrives, with available longer- range high resolution models not showing much in the way of thunderstorms across western Minnesota by 21-00Z. However, the AIFS is much quicker with the entire system, suggesting thunderstorms could develop as soon as early to mid-afternoon across western Minnesota. Once thunderstorms do develop, they are expected to merge into line segments due to the strong forcing & shear orientation along the cold front. Given the environment, a few strong to severe thunderstorms are likely with damaging wind gusts the primary hazard given the linear storm mode. This line of storms will move eastwards through the evening, likely weakening somewhat as the night progresses. Rainfall amounts from these storms is expected to be heaviest across eastern Minnesota & western Wisconsin as the front stalls out overnight into Friday morning & additional. Widespread rainfall amounts of around an inch are expected across eastern Minnesota & western Wisconsin, while lower amounts of 0.1-0.25" are more likely across western Minnesota where storms will be more sparse.

Temperatures return to more seasonable values behind the cold front over the weekend & remain seasonable cool into next week. The next round of precipitation is expected late Sunday through Monday as an organized upper level low moves through the Upper Midwest.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1240 PM CDT Tue Apr 21 2026

VFR conditions through the period. Clear skies expected, although some high passing cirrus may occur from time to time. Northerly winds will become more easterly tonight into Wednesday morning, all with speeds under 10kts. A shift to southerly tomorrow afternoon will be associated with an increase in speeds to 10-15kts, gusting to 20kts (add 5-10kts for western MN).

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/ THU...MVFR/-RA likely, mainly PM. Wind S 10-15G25-30 kts. FRI...VFR. Wind. W 10-15G25kts. SAT...VFR. Wind NW 10G20kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...Fire Weather Watch from Wednesday afternoon through Wednesday evening for Benton-Carver-Douglas-Freeborn-Le Sueur-Mille Lacs-Morrison-Rice-Scott-Sherburne-Stearns-Steele-Todd- Waseca-Wright. Red Flag Warning from noon to 8 PM CDT Wednesday for Blue Earth-Brown-Chippewa-Faribault-Kandiyohi-Lac Qui Parle- Martin-McLeod-Meeker-Nicollet-Pope-Redwood-Renville- Sibley-Stevens-Swift-Watonwan-Yellow Medicine. WI...None.