textproduct: La Crosse

KEY MESSAGES

- Afternoon storms mostly in northeast Iowa may spread east into southwest Wisconsin and north towards the Minnesota border. Evening and nighttime storms dive south-southeast primarily affecting southeast Minnesota, weakening as they approach depending on diurnal timing.

- Potential for slightly cooler temperatures with storms circumnavigating the forecast area through the start of the week.

UPDATE

Issued at 1221 PM CDT Sat Jul 4 2026

Funnel Cloud Potential This Afternoon:

The airmass across northern Iowa early this afternoon is spreading east-northeast towards the forecast area with reports of Funnel Clouds. Combination of mostly clear skies causing steep low level lapse rates with weak low level winds is increasing Non-Supercell Tornado values near 2 well west of the local forecast area. Given the environment, overall confidence and impact threat is low as funnel clouds are usually brief, dropping only a few hundred feet from the cloud base, and rarely become a tornado or cause damage. Have issued an SPS through 7PM for the possibility in northeast Iowa where local threat is highest.

DISCUSSION

Issued at 137 PM CDT Sat Jul 4 2026

Storm Chances This Afternoon/Evening:

Burbling storms along residual past storm outflow boundaries have caused storms in southwestern counties of the local area in northeast Iowa. Expect these to continue spreading east through the early afternoon, potentially continuing through southwest Wisconsin towards Lake Michigan. The accompanying instability gradient also extends north-northwest through southeast Minnesota where recent radar reflectivity has exhibited isolated, single cell, short-lived storms burbling early this afternoon.

Storm Chances This Evening & Tonight:

Storm probabilities increase through the late evening into tonight primarily in southeast Minnesota as the storms in central to northern Minnesota early this afternoon fall southeast along a weak upper level perturbation. Current timing slightly after diurnal heating suggests a weakening trend as storms approach the forecast area while instability recedes southwest. Therefore, diurnal timing will be the main concern after any, limited, transient, isolated weak storms. Location of longer duration storms this afternoon consuming available instability will also influence instability into tonight. Longer duration storms will limit subsequent unstable air, limiting nighttime storms.

Through The New Week:

A weak low formation over the Great Lakes through Sunday drags a back door cold front over much of the Upper Mississippi River Valley. Long term global ensembles and accompanying deterministic models agree for this area of cyclonic rotation lingering through midweek, resulting in locally cooler temperatures than surrounding areas and a shield of precipitation probabilities potentially. Differences in strength and location of the low pressure will be the main driving factor for local weather impacts as a stronger solution will result in stronger east winds off the Great Lakes causing cooler temperatures and less precipitation chances for much of the local area. Peripheral storms and precipitation will remain possible regardless.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 622 PM CDT Sat Jul 4 2026

Isolated to scattered showers and storms may continue through this evening. Rain chances become low after midnight. A low chance (10 to 30%) exists for showers and storms to be possible again on Sunday afternoon and early evening. Mostly VFR conditions, with the exception that with a moist atmosphere and light winds, fog or stratus may form. With some high cloud potential, this would favor more of a stratus deck rather than fog. We will see how the early overnight goes to see which scenario begins to play out. Will update TAFs accordingly once confidence has increased on which scenario occurs.

ARX WATCHES/WARNINGS/ADVISORIES

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