textproduct: La Crosse

KEY MESSAGES

- Hazardous heat continues today with heat indices in the mid 90s to low 100s.

- Smoke from Canadian and northern Minnesota wildfires will move over much of the forecast area today and again on Thursday.

- Rain chances return Thursday afternoon (10 to 15%).

DISCUSSION

Issued at 1254 AM CDT Wed Jul 15 2026

Staying Warm Through Late Week:

The anomalous mid-upper level ridge seen degrading and stretching from the Upper Mississippi to Ohio River Valleys Tuesday night. Resultant warmest surface temperatures will bifurcate the forecast area, perpetuating ongoing Heat Advisories with heat indices nearing 100 degrees in these areas.

Wildfire Smoke & Air Quality Impacts:

Increasing forecast concern from near surface wildfire smoke concentrations through Thursday as northerly winds advect particulates from Canadian wildfires into the Upper Midwest. Current forecast confidence for synoptic convergence along the forecast area keeps gradient of smoke concentrations from southwest to northeast. Therefore, while Air Quality Alerts have been issued in Wisconsin, lower confidence in our southwestern peripheral counties of northeast Iowa may result in lack of Air Quality Alerts there and in additional counties of southeast Minnesota. Otherwise, have slightly decreased temperatures through Thursday in collaboration with neighboring offices due to increased wildfire smoke concentrations inhibiting incoming shortwave solar radiation.

Precipitation Chances Thursday:

Furthermore, as the north wind sags south, the moisture boundary suggests some chance for precipitation. While current confidence for storm initiation remains low to due overall lack of forcing, moist PWATs (1.25+) with little synoptic progression raises concerns of heavy rain should storms persist.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 545 AM CDT Wed Jul 15 2026

Fog has formed in many river valleys across the region. This fog will dissipate over the next few hours. After the fog dissipates, smoke from Canadian and northern Minnesota wildfires moves in this afternoon and lingers through the day on Thursday. As a result, some locations may see reduced visibilities due to the smoke. There remains not enough confidence to put smoke in the TAFs at KLSE and KRST. If confidence grows that this smoke will lower visibilities enough at both airports then smoke will be put in the TAFs. Winds are light and variable for the forecast period.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Heat Advisory until 8 PM CDT this evening for WIZ029-032>034- 041>044-053>055-061. MN...Heat Advisory until 8 PM CDT this evening for MNZ079-086>088- 094>096. IA...Heat Advisory until 8 PM CDT this evening for IAZ010-011-030.