textproduct: La Crosse

KEY MESSAGES

- Dry and unseasonably cool today.

- Low chances (<10%) for severe storms Tuesday afternoon through Wednesday morning.

- Temperatures gradually warming from Thursday through Sunday.

UPDATE

Issued at 233 AM CDT Mon Jun 22 2026

Dense Fog Advisory Issued:

Have issued a Dense Fog Advisory for select counties in northeast Iowa based on satellite imagery, surface observations, and reports from Law Enforcement. Satellite imagery exhibits a slow eastern shift to low level stratus and foggiest conditions and therefore have kept overall duration short, set to expire at 5AM CDT. However, may need to be extended temporally should fog linger, or even spatially if fog becomes realized farther east. Overall reports have been transient, limiting overall confidence outside of current observations.

DISCUSSION

Issued at 133 AM CDT Mon Jun 22 2026

Today:

A Canadian high pressure system will build across the area on Monday. Under partly to mostly sunny skies, temperatures will climb into the 70s which are 5 to 10 degrees cooler than normal.

Tuesday through Tuesday night Storm Chances:

A shortwave trough will be approaching the region from the Northern Plains. The highest chances form showers and storms will be west of the Mississippi River Tuesday, spreading across the entire area into Tuesday night. There continues to be much uncertainty on the amount of instability across the area due to the amount of convective debris clouds across the area. Many models limit MUCAPE to 250 J/kg or less. The strongest 0-6 km shear (around 45 knots) is along and north of Interstate 94, resulting in highest local probabilities for severe in this area.

There is some concern that the high temperatures on Tuesday may be too warm. We are currently forecasting high temperatures from the mid-70s to lower 80s. However, if the convective debris clouds are too thick, we may have to cool them closer to the NBM 10th percentile which has high temperatures ranging from the upper 60s to mid-70s.

Tuesday Temperatures:

Some concern that high temperatures on Tuesday are overly warm with current forecasts for mid-70s to lower 80s. If incoming convective debris clouds are thick and more impactful, can expect a cooler forecast, closer to the NBM 10th percentile ranging high temperatures from the upper 60s to mid-70s.

Wednesday:

The shortwave trough will move east through the region on Wednesday morning. Surface-based CAPE climbs from 750-1750 J/kg as 0-6 km shear will be in the lower 40s ahead of this front. As a result, there may be a brief window for some severe weather on Wednesday morning in the form of a squall line. If severe weather happened to occur, the primary threat would be damaging winds.

High temperatures will range from the lower 70s to lower 80s. The warmest temperatures would be in the river valleys.

Thursday through Sunday:

Much of this period looks to be dry. If there is any rain, it would be from Friday into Saturday as a warm front move through the region. High temperatures will gradually warm from the upper 60s to mid-70s on Thursday and range from the upper 70s to mid-80s by Sunday.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1238 AM CDT Mon Jun 22 2026

LIFR-IFR Fog affecting Wisconsin River Valley and south-central Wisconsin (KVOK, K82C) expected to continue through the overnight into early Monday morning before lifting. While KLSE isn't affected directly, surrounding ridgetops are seeing <1/4SM from low level stratus and therefore have included VCFG through the overnight hours. Will require further assessment at subsequent (22.12Z) TAF issuance.

VFR expected through the rest of the period with similar nighttime fog possible in aforementioned areas Monday night into Tuesday morning.

ARX WATCHES/WARNINGS/ADVISORIES

WI...None. MN...None. IA...Dense Fog Advisory until 5 AM CDT early this morning for IAZ009-010-018-019.