It should be too foggy for Jimmy the Groundhog to see his shadow Thursday morning, which would mean an early spring.

Based on the weather this week and the forecast for the next seven days, that's already happening.

A dense fog advisory has been issued for southern Wisconsin, including Dane County, until 10 a.m. Thursday, with visibility reduced to a quarter-mile or less in some parts.

The advisory from the National Weather Service said below freezing temperatures with dense fog could result in frost forming on untreated roads and walks and the reduced visibility will make for hazardous travel.

"If driving, slow down, use your headlights and leave plenty of distance ahead of you," the advisory said.

The fog is expected to dissipate by mid-morning, giving way to a mostly sunny day with a high in the mid-40s.

Fog could return Thursday night into Friday morning, the Weather Service said, with conditions improving by mid-morning on Friday under partly sunny skies with a high of 43.

A storm system to the south could brush across far southern Wisconsin during the weekend, bringing a slight chance of a rain and snow mix to Madison.

27 Storm Track meteorologist Brian Olson said the light mix of precipitation could come into the area in the afternoon and evening, mostly in the southern reaches of the state, close to the Illinois state line. The high should top out at 37.

The mix could linger into Saturday night and early Sunday, before skies turn mostly sunny on Sunday with a high near 40.

Monday should be mostly sunny with a high of 42, Olson said, before cooler weather moves in.

Madison should expect sunshine and highs in the low to mid-30s on Tuesday, Wednesday and next Thursday.

Wednesday's high in Madison was 42, 14 degrees above normal and 5 degrees below the record high of 47 for Feb. 1, set in 1968.

The low on Wednesday was 26, 14 degrees above normal and 54 degrees above the record low of 28 below for the day, set in 1985.

No precipitation fell at the Dane County Regional Airport on Wednesday, so Madison is 0.04 inches below normal in total precipitation (rain plus snow converted to liquid) for February.

For the meteorological winter of December through February, Madison has received 3.63 inches of precipitation, or 0.62 inches above normal.

Snowfall is 0.4 inches below normal for the month since no snow fell on Feb. 1.

For meteorological winter, Madison has received 15.9 inches of snow, or 10.9 inches below normal.

Since the start of the snow season on July 1, Madison has received 17.5 inches of snow, or 13.4 inches below normal.

The record snowfall in Madison for Feb. 1 was the 8.3 inches that fell last year during the Groundhog Blizzard of 2011, which officially dumped 18.7 inches on Madison on Jan. 31 through Feb. 2.