textproduct: La Crosse

KEY MESSAGES

- More rain tonight, mainly for northeast Iowa and southwest Wisconsin where 0.25 to 0.75" will be possible (40 to 70% chance).

- Warming into the weekend and early next week as highs get into the 70s for Sunday and Monday.

- Periodic rain and thunderstorms expected Saturday into Monday. Will need to monitor for heavy rainfall with these storms and for the potential of severe storms late Monday.

DISCUSSION

Issued at 1239 AM CDT Thu Apr 9 2026

Today and Tonight: Cooler with More Rain South of I-90

Temperatures today will be closer to normal, towards the low to mid 50s. Our cold front that passed through yesterday evening will stall to our south across Iowa. A shortwave dips down into the Upper Midwest interacting with this cold front. Moisture transport increases ahead of this wave as southerly 850mb winds help to push moisture northward. Showers and thunderstorms develop in Iowa and Illinois in the afternoon while northeast Iowa and southwest Wisconsin see rain move in this evening. Rain totals are generally in the 0.25 to 0.5" range except for far southern portions of Fayette, Clayton, and Grant counties where up to 0.75" will be possible. Rainfall amounts will taper off quickly to the north with little accumulation expected up towards I-90.

Saturday Afternoon - Monday: Warming up, Periodic Storms

The end of the week will see near to slightly above normal temperatures as a high pressure system translates across the Upper Midwest. The longwave pattern undergoes a notable transformation to start the weekend as a broad trough sags along the west coast starting Friday and lasting into Monday. The preceding upper level ridge axis passes through during the day on Saturday, with increasing theta-e advection fueling a corresponding risk for showers and storms starting Saturday afternoon through at least Monday--possibly through Tuesday night. While some of the basic ingredients are in place for heavy rainfall, the medium range solutions are struggling to latch onto any solid forcing mechanism to make this rainfall a reality. The best chance for heavy rainfall is looking to be Saturday evening into Sunday morning and possibly again on Monday, but these details remain to be fleshed out and are of lower confidence. As far as severe potential late Monday, a corridor of MUCAPE is progged to develop across our area, overlapping with 0-6km shear of 30-40kts. This would support some stronger storms Monday evening and overnight if these factors are realized, but there is plenty of time for variation over the coming days. The SPC currently has us outlined in a 15% which is in agreement with AI/ML convective guidance, so will be another period to monitor.

Above normal temperatures look to linger into the new week as EFI values for Sunday and Monday highlight nearly the entire forecast area in the 0.8 to 0.9 range. The 09.01z NBM mean suggests highs reach into the 70s, around 20 degrees above normal, while lows fall into the 50s and 60s, around 25 degrees above normal. Looking at the 09.00z GEFS/EPS/AIGEFS/AIFS, there is some spread in the temperature solutions, generally on the order of 5-10 degrees, but most of the members of these ensembles cluster around the NBM mean, resulting in an overall trend towards above normal temperatures to start the new week.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 544 AM CDT Thu Apr 9 2026

Little impact to aviation is expected through much of the day outside of some low end VFR to MVFR ceilings along and north of I-94 this morning, sitting right around 3kft. Thinking these ceilings will begin to lift through the morning to become solidly VFR by the afternoon with some scattering out suggested by HRRR soundings. Northwest winds prevail through the TAF period generally 5-10KT although a few gusts of 15-20KT are possible this morning. A period of rain moves into the region after 23z, most favorable south of I-90 (70-90%). MVFR conditions should accompany the rain and linger for awhile after as the 09.00z REFS/HREF indicate a 30-50% probability for ceilings less than 3kft. Visibility will also be reduced in any showers, most favorable over northeast Iowa and southwest Wisconsin where the heaviest rain is expected. Rain shifts east of our area by 10z Friday.

ARX WATCHES/WARNINGS/ADVISORIES

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