textproduct: La Crosse

KEY MESSAGES

- Areas of frost are expected for portions of north-central and central Wisconsin tonight into Monday morning.

- Outside of the low potential for showers north of I-94 Monday night into Tuesday morning, dry conditions are expected this week.

- Near to slightly above normal temperatures are expected through this week with highs in the 60s and 70s.

DISCUSSION

Issued at 1225 PM CDT Sun Oct 4 2026

Rest of Today - Monday Morning: Areas of Frost Tonight

Rather benign weather is expected through the remainder of the afternoon though some northwest wind gusts of 20-25mph are possible across the Upper Mississippi River Valley, though favored across portions of north-central to central Wisconsin given a well mixed boundary layer and 925-850hPa winds of 25-30mph.

Heading into tonight, winds begin to diminish as low level ridging and high pressure move into the region. Clear to mostly clear skies are also expected which should allow for fairly efficient cooling across the Upper Mississippi River Valley. This cooling combined with the light winds and mostly clear skies leads to a favorable set- up for frost development as temperatures approach and fall below the 37 degree mark, especially over the sandier areas of north-central to central Wisconsin where the 04.13z NBM suggests a 10-20% chance for temperatures to approach freezing. Have maintained the Frost Advisory due to this potential.

Monday - Friday: Mostly Dry, Near to Slightly Above Normal Temperatures.

Dry conditions are expected throughout the week with the only exception being Monday night into Tuesday morning as a 700hPa shortwave trough moves eastward across the Upper Midwest. While the majority of the region is also expected to remain dry during this period, probabilities for measurable rainfall have increased for those north of I-94. The 04.00z LREF does have some higher probabilities compared to other ensemble guidance, sitting around 10-30% compared the the NBM at ~10%. Thinking the reason for this discrepancy is the LREF is largely inflated by its EPS membership which suggests deeper moisture present across the region, resulting in probabilities nearing 50% whereas other solutions such as the GEFS/GEPS are on the drier side and suggest little to no potential in our area, keeping rainfall to the north. Tending towards the NBM solution for the time being, but if the shortwave trends southward or the GEFS/GEPS solutions trend towards increased moisture, probabilities for rainfall will likely increase.

Otherwise, little in the way of airmass change is expected throughout the week under northwest flow which results in fairly stagnant, near to just above normal temperatures for this time of year. The exception also comes Tuesday when high temperatures are favored to climb into the low 70s behind a warm front that lifts north as the aforementioned wave moves through the region and low level thermal ridging builds in, but fall back towards normal Thursday behind a cold front.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1225 PM CDT Sun Oct 4 2026

VFR conditions are forecast over the next 24 hours. The wind will be out of the northwest this afternoon with some gusts up to 20 kts. The wind will decrease after 00z through the remainder of this TAF cycle and should remain below 10 kts. Mostly clear skies are expected.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Frost Advisory from 1 AM to 9 AM CDT Monday for WIZ017-029-034- 042>044. MN...None. IA...None.