textproduct: La Crosse

KEY MESSAGES

- Rain chances (20 to 50 percent) mainly west of the Mississippi River this weekend.

- Periodic rain chances for next week with above-normal temperatures.

DISCUSSION

Issued at 1230 AM CDT Sat May 30 2026

This Weekend

The omega high will gradually drift east this weekend. As this occurs, the upstream trough will move just far enough east that areas west of the Mississippi River will have a 20 to 50 percent chance of showers and storms. In addition to the rain chances, 850 mb temperatures will cool by 1 to 2C. This will result in high temperatures ranging from the mid-70s to around 80. Low temperatures will range from the the mid-40s to upper 50s tonight, and range from the lower 50s to lower 60s on Sunday night.

The winds west of the Mississippi River will increase into the 10 to 20 mph with maybe a gust to 25 mph this afternoon. Fortunately the relative humidity values will be in the 30s and 40s. Meanwhile, in western Wisconsin, the winds will range from 10 to 15 mph. This is good because this is where the afternoon relative will be in the 20s and 30s.

Monday and Monday night

A col region develops over the Upper Mississippi River Valley. A trough moves north into this region and gets stretched and weakens over time. This will allow for a better chance of showers and storms. Still plenty of uncertainty on how far east the better instability (up to 2500 J/kg) will get. In addition, there are questions on how strong will be the 0-3 km shear. The operational GFS would suggest the possibility of a few strong to potentially severe storms in northeast Iowa on Monday evening. Meanwhile, the operational ECMWF has very little 0-3 km shear. As a result, the chances for organized severe convection is far less for the area if that model solution occurs.

Tuesday into Tuesday night

The omega high will re-establish itself over the Upper Mississippi River Valley on Tuesday, and then linger into Tuesday night. As this occurs, high pressure will build across the area. As a result, the area will be dry with high temperatures in the lower and mid-80s.

Wednesday into Friday

The omega high over the Upper Mississippi River Valley and Great Lakes on Wednesday and Wednesday night will flatten and become zonal. This will bring a return to better chances for showers and storms. 0-1 km ML CAPES will be up to 750 J/kg on Thursday afternoon and evening. In addition, the 0-3 km shear climbs up 30 knots. This might result in a few strong storms.

High temperatures will be in the lower and mid-80s and low temperatures will range from the mid-50s to mid-60s.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1230 AM CDT Sat May 30 2026

BKN high clouds persist through the TAF period with east to southeast winds. Overnight wind speeds of 10KT or less increase this afternoon bringing gusts of 15-20KT into the evening hours before diminishing again overnight Saturday.

ARX WATCHES/WARNINGS/ADVISORIES

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