textproduct: La Crosse

KEY MESSAGES

- Dry through Friday.

- Elevated smoke moving into the area on Friday afternoon. It will likely persist through the weekend. Any surface smoke will likely remain well west of the area.

- Periodic showers and storms from Friday night into Monday night. A few could be strong to severe on Saturday night/Sunday and from Sunday night/Monday.

DISCUSSION

Issued at 1128 AM CDT Thu Jul 23 2026

Through Friday

A surface high pressure will provide dry weather through Friday. The HRRR is indicating that the northwest winds aloft will bring elevated smoke into the area on Friday afternoon. The highest concentrations will be along and north of Interstate 90. While elevated smoke does move into the area, southerly winds will keep surface smoke from moving into the Driftless Area. This surface smoke gets as far east as the central Dakotas and then southerly winds abruptly stops its eastward progress.

Unlike the past 2 mornings, high clouds, dry dew points, and increasing winds in the boundary layer will likely limit development of fog in the Wisconsin River Valley and the Mississippi and Wisconsin River tributaries.

Lows will be in the 50s tonight. High temperatures on Friday will range from the mid-70s to lower 80s.

Friday night and Saturday

A shortwave trough will move east through the Upper Mississippi River Valley overnight Friday and Saturday morning. In response of this system, a Canadian cold front will move southeast into the region. This front will get as far south as either the Interstate 90 or 94 corridor. Scattered showers and a few storms will accompany this front. With lessening instability during the night, kept precipitation chances generally less than 30 percent mainly north of Interstate 94. Low temperatures will range from the upper 50s to mid-60s.

During the afternoon, the front will move back to the north as a warm front as the 500 mb ridge build across the region. High temperatures will range from the mid-80s to lower 90s. Heat indices will be mainly in the 90s. Closer to Interstate 35, the heat indices may be around 100.

Saturday night into Sunday

It still looks like a mesoscale convective complex will develop upstream of the Upper Mississippi River Valley and then move southeast through the region during the overnight. There continues to be much uncertainty on the track of this system. With the 0-3 km and 0-6 km shear and instability looking stronger, there might be a threat of severe weather. With enhanced winds aloft, the primary threat looks to be damaging winds. In addition, large hail and isolated tornadoes could be lesser threats.

Low temperatures will range from the mid-60s to lower 70s on Saturday night. High temperatures will range from the mid-80s to mid-90s. The heat indices look to be a bit higher (ranging from around 100 to 105) along and west of the Mississippi River. It continues to look like a Heat Advisory will be needed.

Sunday Night into Monday Night

The 500 mb ridge will gradually retrograde west and southwest early next week. As this occurs, a Canadian cold front will move south through the region. Severe weather chances will be highly dependent upon when this front moves through the region. If it can move through the afternoon and evening, our probabilities would be higher due to the higher instability. If it moves through the area later in the evening and overnight, the probabilities would dramatically fall.

Low temperatures on Sunday night would range from the upper 60s to mid-70s. High temperatures on Monday have increased and they now range from the mid-80s to mid-90s. Heat indices will be in the 90s north of Interstate 90 and range from around 100 to 105 south of Interstate 90. Another Heat Advisory may be needed for northeast Iowa and southwest Wisconsin.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 636 PM CDT Thu Jul 23 2026

VFR conditions are expected throughout much of the TAF period with southerly winds increasing to 8-12 kts by afternoon tomorrow. Valley fog appears unlikely at KLSE given fairly strong low-level winds just off the surface. Cannot rule out (~10% chance) some precipitation making it into KRST overnight with a disturbance passing to the south, however confidence remains too low to include any mention.

ARX WATCHES/WARNINGS/ADVISORIES

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