textproduct: La Crosse

KEY MESSAGES

- Valley fog likely overnight.

- Above-normal temperatures are expected through the remainder of this week. Used NBM 90th percentile to raise the high temperatures 2 to 5F.

- Temperatures look to be cooler and wetter next week. However, there is still plenty of uncertainty with the temperature and precipitation probabilities.

DISCUSSION

Issued at 1136 PM CDT Wed Oct 21 2026

Overnight

Like last night, the combination of clear skies, light winds, and dry dew points has resulted in strong radiative cooling this evening. The current temperatures are already approaching the forecast low temperatures for overnight. Due to this, lowered the overnight low temperatures by using a 50-50 blend of the NBM and the NBM 10th percentile for most areas. In central Wisconsin, went 100 percent NBM 10th percentile. This resulted in low temperatures ranging from the mid-30s to mid-40s.

With a deep layer of light winds up 8K feet overnight, we should see valley fog develop overnight. There are already signs of it developing on our office web cam. This valley fog should gradually dissipate between 22.15z and 22.16z.

Today through Saturday

Through Saturday, a strong 500 mb ridge will remain in control of the area's weather. This high will provide dry weather and unseasonably warm temperatures. With the NBM running on the cool side much of last week and since Sunday, used the NBM 90th percentile to raise the high temperatures by 2 to 5 degrees from today through Saturday. This resulted in high temperatures ranging from the upper 60s to mid-70s through Saturday.

With the NBM being a bit too warm on low temperatures for the past 3 nights, used a 50-50 blend of the NBM and NBM 10th percentile to lower them for tonight. This resulted in low temperatures tonight ranging from the mid-40s to mid-50s. On Friday and Saturday nights, the low temperatures will range from the upper 40s to mid-50s.

Sunday into Wednesday

From Sunday into Monday, a trough of low pressure will move east across Manitoba and Ontario. This will drag a cold front slowly southeast into the forecast area. There remains plenty of uncertainty on how far south this front will get. Some keep it mainly to our north. Others drop this front south as Interstate 80. This result in much uncertainty on temperatures and where the heaviest rain will occur. It still looks like this front will be capable of producing rain amounts up to a half-inch wherever it ends up.

From Monday night into Wednesday, this front will likely meander across the region. This will impact both temperatures and precipitation probabilities.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 630 PM CDT Wed Oct 21 2026

With clear skies and a deep layer of light winds up 8K feet, valley fog should develop overnight and linger through 22.15z. This will likely impact KLSE. KRST will likely remain VFR through the TAF period.

ARX WATCHES/WARNINGS/ADVISORIES

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