textproduct: La Crosse

KEY MESSAGES

- Heavy rain tonight and Thursday morning in Fayette and Clayton counties in northeast Iowa, and Grant County in southwest Wisconsin. The far southern portions of these counties may see 2 to 4 inches with localized higher totals.

- Central and north-central Wisconsin may see patchy to areas of frost on Friday night and areas to widespread frost on Sunday and Monday nights.

DISCUSSION

Issued at 1205 PM CDT Wed Sep 30 2026

Tonight and Thursday

The remnants from Hurricane Polo will move northeast through Iowa, northern Illinois, and the southern third of Wisconsin tonight. Precipitable water values late tonight will quickly climb and range from 2 to 2.25 inches across southern and eastern Iowa, northern Illinois and far southern Wisconsin. Precipitable water values will be around 1.5 inches in La Crosse, and around 1 inch near Black River Falls. The heaviest rain will likely fall from Omaha, NE to Dubuque, IA to Grand Rapids, MI. Mean rainfall totals will likely range from 2 to 5 inches. The 24-hour QPF ensemble localized probability-matched means are as high as 7 inches. These may impact far southern Fayette and Clayton counties in northeast Iowa and Grant County in southwest Wisconsin. Rainfall totals quickly decline as you move northeast toward to La Crosse where rainfall totals will likely range from a quarter- to half-inch and only up to a tenth of an inch near Interstate 94. As the surface wave moves quickly away from the area on Thursday morning, the precipitable water values will quickly drop and the rain will move out of the area. Most areas should have a dry afternoon.

Low temperatures tonight will range from the mid-50s to mid-60s. High temperatures on Thursday will be in the mid- to upper 60s.

Thursday Night into Friday Night

High pressure will provide dry weather. High temperatures will range from the upper 50s to mid-60s on Friday. Low temperatures will range from the upper 30s to upper 40s on Thursday night, and from the mid- 30s to mid-40s on Friday night. The temperatures will be cold enough on Friday night that there could be some areas of frost in central and north-central Wisconsin.

Saturday and Saturday Night

A cold front will move southeast through the area from late Saturday afternoon into Saturday evening. This front could produce some scattered light rain showers as it moves southeast through the Upper Mississippi River Valley. High temperatures will be in the mid-60s on Saturday, and low temperatures will range from the mid-40s to lower 50s.

Sunday through Tuesday Night

High pressure will provide dry weather. High temperatures will range from the upper 50s to mid-60s. Low temperatures will range from the lower 30s to mid-40s on Sunday and Monday nights. The temperatures will be cold enough for areas to widespread frost in central and north-central Wisconsin. Low temperatures will range from the mid- 40s to mid-50s on Tuesday night.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 654 PM CDT Wed Sep 30 2026

VFR to IFR CIGs currently present across the area with the batch of heavy rainfall expected to impact our area through the overnight hours and into tomorrow slowly working its way north out of east central Iowa this evening. This will gradually make its way into the Upper Mississippi Valley over the coming hours with CIG and visibility degradation following shortly. IFR/LIFR CIGs and fog development should impact most of the area including both of the terminals overnight and into the morning hours. Winds should remain elevated in speed enough to prevent the fog from becoming dense but patchy areas of 1 mile visibility or slightly less will certainly be possible near daybreak tomorrow morning. Conditions at the terminals will improve through the late morning and into the afternoon with CIGs scattering out to VFR and rain pushing off to the southeast as a cold front makes its way into the region, bringing a drier airmass along with it.

ARX WATCHES/WARNINGS/ADVISORIES

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