textproduct: La Crosse

KEY MESSAGES

- The risk for severe storms across the region is increasing for Friday afternoon with all hazards possible. The main uncertainty in the forecast revolves around when the storms form, which will dictate what areas see a certain threat. Continue monitoring forecast for further details.

- Near to below freezing overnight low temperatures through the weekend. A few snow flurries cannot be ruled out on Saturday, mainly along and northeast of I-94.

DISCUSSION

Issued at 1159 PM CDT Wed Apr 15 2026

Dry Today:

A reprieve in storm chances today from passing anticyclonic flow ushering in a drier airmass will feel less humid compared to previous days with surface dewpoint temperatures in the 40s to low 50s. The break in precipitation also allows over saturated soils to recover some from heavy, high rainfall amounts over the last few days. Fire weather concerns expected to remain northwest of the local forecast area into central Minnesota.

Severe Storms Likely Friday:

A stout longwave upper level trough seen progressing east over the Pacific Northwest on GOES water vapor loops excites low level moisture transport through the Central to Northern Plains Thursday, progressing through the Upper Mississippi River Valley Friday. Accompanying instability of 2000+ J/kg MUCAPE seen in low and high resolution models builds through the forecast area before eventual fropa Friday night. While LREF dProg/dt remains mostly consistent, a slightly more phased solution to the low has increased intraensemble agreement for a deeper low pressure center slightly farther north from west-central into northern Wisconsin. The concurrent steep mid level lapse rates (GFS 15.18Z) of 9.5C+/km raise initial supercell concerns through Friday afternoon as a meso low phases/occludes along our western/northern periphery.

Therefore, model derived significant severe parameters illuminate initial stronger severe threats during supercellular storm mode Friday afternoon through some of the forecast area before fropa causes linear storm mode to progress from northwest to southeast through the evening into the nighttime hours. All storm modes remain possible with highest potentially strong tornado threat during the afternoon should surface based supercells form along a lifting boundary. Tornadoes within linear storm mode later through Friday remain possible albeit potentially not as strong. Very large hail and damaging winds will be possible with all storm modes.

Winter Resemblant Weekend Expected:

A colder airmass settles in through the weekend, ushering in winter precipitation chances Saturday into Saturday night. Deepening on growing season, confidence in near to below freezing overnight low surface temperatures may require subsequent Frost Advisory or Freeze Warning issuance Friday, Saturday, and Sunday nights. Unfortunately, low (<15%) LREF joint probabilities for shear and CAPE graze the local forecast area again by the middle of next week.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1221 PM CDT Thu Apr 16 2026

VFR currently present at the terminals and expected for the next 24 hours. Light and variable winds will prevail early in the period before becoming more southerly later this afternoon. Winds will gradually increase through the overnight hours and especially during the morning hours tomorrow where gusts to 25 to 35 kts will be possible. A line of storms ahead of a cold front are expected to impact the terminals after 18Z Friday.

HYDROLOGY

Issued at 535 AM CDT Thu Apr 16 2026

Dry conditions today provide a temporary reprieve for saturated soils and localized flooding. Crests for ongoing rivers in flood across Wisconsin will work downstream into early next week. Unfortunately, heavy rain potential increases Friday afternoon as a line of storms progresses from west to east. The heaviest rainfall amounts of 1-2 inches are likely to fall in narrow corridors, but will be dependent on how quickly storms grow into a line versus remaining isolated. The highest confidence in higher rain amounts will be east of the Mississippi where rivers will still be in flood. Continue monitoring upcoming forecasts for the location of highest QPF amounts.

ARX WATCHES/WARNINGS/ADVISORIES

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