textproduct: La Crosse

KEY MESSAGES

- A band of showers and storms sweeps through the region this evening. While the severe weather threat looks to stay just northwest of the local area this evening, one cannot fully rule out a weak tornado northwest of a Rochester, MN to Wausau, WI line.

- While cooler after today, near to above average temperatures linger into early next week with the threat for rain returning mainly Friday into Saturday and again late Monday into Tuesday.

DISCUSSION

Issued at 148 PM CDT Wed Oct 28 2026

This Afternoon and Tonight: Shower and Storm Details

Convective initiation has already taken place across west- central Minnesota ahead of a shallow mid to upper tropospheric shortwave trough lifting northeastward through the Dakotas and Manitoba. Additional showers and storms will continue to develop within this corridor of mid-level frontogenesis and theat-e advection, with cells likely growing upscale into clusters and lines in short order after initiation. Forecast soundings and hodographs over the Twin Cities still show the potential for embedded tornadoes with any organized lines or clusters, but given the narrow warm sector, the convective complex is expected to start outrunning this instability axis by the time it reaches our forecast area after 22-00Z.

The main wild card in the forecast revolves around how convection ahead this complex develops through the afternoon and evening. There are hints in the explicit HRRR progs that more discrete cells develop over southern Minnesota and lift northeastward with time, which will have a better opportunity to realize the limited instability (MLCAPE of 400-700 J/kg) but favorable lower tropospheric shear profiles and possibly produce a few weak tornadoes. The main area of concern for this is mainly along and west of a Rochester, MN to Wausau, WI line between 22-02Z.

Friday and Saturday: Trick or Treating Rain Possibilities

Broad subtropical high pressure lingers over the southeastern U.S. for Friday and Saturday, with return southerly flow working northward along its western flank during this time. The theta-e advection driven showers creep northward through the day on Friday, lifting through the rest of the forecast area Friday night into Saturday. However, with the upper level support waning during this time as the northern stream jet streak advances into Ontario, the showers should gradually lessen in intensity with the highest probabilities for 1/4-1/2 of an inch of rain (20-40%) staying over Iowa and lessening quickly as one travels north. The slow-moving and decaying nature of the showers on Saturday makes it harder to pinpoint exactly what areas will be dry for Trick-or-Treating, so stay tuned for further updates as we get closer to Halloween.

Early Next Week: More Widespread Rain

A more dynamic weather setup evolves for the start of next week as an energy exchange takes place between a pair of northern and southern stream waves over the Rockies, resulting in a rapid deepening and closing off of the southern wave as it moves towards the TX/OK panhandles on Monday and Tuesday. The evolution and trajectory of the wave after this point becomes less certain as the medium range solutions quickly diverge. However, the main story for the local area--being on the northern side of the deformation zone/occlusion--will be a widespread period of rain starting from Monday evening potentially through Thursday. Overall rainfall amounts for the duration of the event could push over 1" (20-30% chance), but spread out over the course of several days with little in the way of impacts other than a span of several dreary days. The exact timing and location of this rain band will be fine tuned over the next few days.

Temperature Trends for the Week

Overall, after today's warmth, a cooler airmass arrives for the rest of the week and into early next week. "Cooler" is a relative term with highs during this period still ranging from the upper 50s to upper 60s, still 5-10 degrees above average for this time of year.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 653 PM CDT Wed Oct 28 2026

Ongoing line of scattered storms shifting north-northeast presenting initial airport impacts. Strength and duration of ongoing scattered storms from northeast Iowa into southeast Minnesota eventually progressing towards and over KLSE TAF site remains low confidence forecast, have included -SHRA VCTS at TAF issuance as a result.

MVFR ceilings expected to shift southeast through the forecast area in wake of storms, accompanying actual frontal boundary progression. Expect impacts to lift through early Thursday morning.

Light and variable winds through Thursday night with subsequent widespread aviation impacts increasing Friday night through Saturday.

ARX WATCHES/WARNINGS/ADVISORIES

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