textproduct: La Crosse

KEY MESSAGES

- Strong to severe storms possible today, primarily for the southeastern half of the forecast area with large hail, damaging winds, and heavy rain causing flooding as the primary concerns. Secondary concern of isolated tornadoes.

- Storm chances continue through Tuesday night and Wednesday, eventually ceasing temporarily through Thursday. Additional strong to severe storm chances return Friday afternoon/evening/night.

UPDATE

Issued at 425 AM CDT Tue Apr 14 2026

With visibilities dropping to 1/2 to 1/4 of a mile in the wake of our rainfall yesterday, have issued a short dense fog advisory to cover the morning commute window. Stratus building southward from west-central WI and the Twin Cities area, could result in the fog lifting from north south and will adjust the advisory footprint as needed over the next few hours.

DISCUSSION

Issued at 1243 AM CDT Tue Apr 14 2026

Strong to Severe Storm Chances Today:

As main line of storms progresses east-southeast of the local forecast area early this morning, return flow is quickly reinvigorating across central Iowa on early morning observations. The 60 degree isodrosotherm roughly collocated with 1" PWATs expected to return through most of the forecast area today aided by Rocky Mountain Low cyclogenesis progressing slightly northeast. Similar to Monday, the initial warm frontal passage increases low precipitation potential through the late morning/early afternoon before additional forcing and instability through the late afternoon and evening further increases local storm threat. Current confidence for northern extent is farther south than Monday, bifurcating the southeastern half of the forecast area with 1000+ J/kg (max 3000 J/kg) of SBCAPE concurrent with little to no SBCIN. The low loses conformity as it progresses northeast, becoming a meager low level trough bifurcating the forecast area. Resultant straight line hodographs exhibit unidirectional shear values capable of splitting supercells causing large hail and damaging winds primarily with an isolated tornado risk.

Storm Chances Tonight Through Wednesday Night:

High resolution models disagree on subsequent storm chances with most frequent storm solution seen in most recent HRRR (14.00Z) perpetuating storm chances Tuesday night, Wednesday morning, Wednesday afternoon, and Wednesday evening as the low level jet converges enhanced moisture along the locally lingering boundary until cyclogenesis and a low level trough passes overnight Wednesday into Thursday. While this is the most frequent outlier solution, most other high resolution models suggest some semblance of frequent storms through Wednesday evening. Similar to Today, large hail and damaging winds will be the main concern with isolated tornadoes possible Wednesday afternoon/evening given diurnal influence permitting convection potentially becoming surface based where storms set up.

Storm Chances Return Friday:

A reprieve in storm and precipitation chances on Thursday ceases Friday as another Rocky Mountain low enhances meridional low level moisture transport, returning strong to severe storm potential for some of the Upper Midwest. While the longer forecast hour limits overall confidence, enhanced cyclogenesis permits increased tapping into the anomalous moisture and accompanying instability, keeping precipitation probabilities high (70%+).

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 550 AM CDT Tue Apr 14 2026

IFR to LIFR stratus and fog along and north of an MCW to ISW line slowly burn off through the daytime hours with a SCT/BKN MVFR CU deck to the south of this line. Showers and storms are expected in this southern corridor as well this afternoon, which could bring large hail and IFR restrictions at times. The clouds look to clear out in the evening with IFR/LIFR fog likely to form overnight in most locales. Winds will generally be light and variable at 10 kts or less.

HYDROLOGY

Issued at 1226 AM CDT Tue Apr 14 2026

Anomalous moisture of the last couple days has resulted in flash flooding where strongest storms result in heavy rainfall. Additional river rises have prompted opening of river gates given expected additional daily precipitation. Highest observations from Monday's storms seen in a band from southeast Minnesota through western and central Wisconsin of 2"+. Therefore, primary area of concern for subsequent flooding would be in these areas should storms progresses as far north Tuesday.

Confidence in rainfall reaching farther north into central Wisconsin Wednesday and Friday keeps heightened awareness for flooding concerns.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Dense Fog Advisory until 8 AM CDT this morning for WIZ029- 032>034. MN...Dense Fog Advisory until 8 AM CDT this morning for MNZ079- 086>088-094-095. IA...None.