textproduct: La Crosse

KEY MESSAGES

- Periodic severe weather and flash flooding will be possible into the weekend.

DISCUSSION

Issued at 140 AM CDT Wed Jul 2 2026

Overnight

As a shortwave trough over southern Wisconsin moves away from the area overnight, the shower and thunderstorm coverage will gradually decrease through 3 am and then the coverage should once again increase as a shortwave trough moves out of southern South Dakota and northern Nebraska and along the Minnesota and Iowa border. This convection will likely be initially along the Interstate 90 corridor and then gradually sink south as it develops a cold pool.

With precipitable water values ranging from 2 to 2.5 inches and warm cloud depths over 4 km, these storms will be highly efficient rain producers. The 6-hour QPF ensemble probability- matched mean from 02.06z and 02.12z has some rain totals in the 2 to 5 inch range. This could result in some flash flooding along and south of Interstate 90.

Today and Tonight

After the morning convection, there is much uncertainty on whether storms will redevelop during the afternoon or not. Many of the CAMs are dry, but the HRRR and RAP13 show another round of showers and storms developing mainly along and south of Interstate 94. These then linger into tonight. Any severe weather threat would be pulsey this afternoon and highly dependent upon the potential of a mesoscale convective complex moving into the area tonight. The main severe weather threats would be damaging winds, large hail, and maybe isolated tornadoes.

Like overnight, the precipitable water vapor will range from 2 to 2.5 inches and the warm cloud depths will be over 4 km. As a result, any storms will be highly efficient rain producers. The 24-hour QPF ensemble probability-matched shows a potential for 3 to 5 inches of rain mainly south of Interstate 90.

Friday into the Issued at 140 AM CDT Wed Jul 2 2026Weekend

A frontal boundary will meander across the forecast area as shortwave trough and surface lows move through the weekend. The timing of these waves is rather uncertain, but as they move through the region the 0-3 km and 0-6 km shear will increase ahead of them and this will provide a chance of supercells and bow echos.

Precipitable water values will remain around 2 inches through the 4th and then gradually decrease to around 1.5 inches as the boundary finally shifts south. Warm cloud layer depths will remain around 4 km. This will result in additional rounds of heavy rain. Flood watches may eventually be needed.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 140 AM CDT Wed Jul 2 2026

Scattered showers and storms will continue for the TAF sites through at 02.14z. Ceilings and visibilities will occasionally be IFR/MVFR with thunderstorms.

HYDROLOGY

Issued at 140 AM CDT Wed Jul 2 2026

During the evening, rainfall totals were up to 3 inches. With precipitable water values ranging from 2 to 2.5 inches and warm cloud depths over 4 km, these storms will be highly efficient rain producers. The 6-hour QPF ensemble probability- matched mean from 02.06z and 02.12z has some rain totals in the 2 to 5 inch range. This could result in some flash flooding along and south of Interstate 90.

Through at least July 4, precipitable water values will remain around 2 to 2.5 inches and warm cloud layer depths will be around 4 km. This will result in additional rounds of heavy rain. Flood watches may eventually be needed.

ARX WATCHES/WARNINGS/ADVISORIES

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