Lake Michigan could see 10-foot waves Monday; shoreline flooding possible

Strong winds of 20 to 30 mph with gusts of 40 to 50 mph blowing in from the southeast across Lake Michigan on Monday could create waves as high as 10 feet.

Cue the opening drumbeat of TV show "Hawaii Five-0."

The National Weather Service has issued a lakeshore flood advisory until 10 p.m. Monday with areas along Ozaukee and Sheboygan counties particularly susceptible to flooding.

A wind advisory - when winds of at least 45 mph are forecast - is in effect until 2 p.m. 

"The first step is the winds, they're (moving) onshore. The next component is the strength of the winds, that builds the higher waves, which then results in lakeshore flooding," said Paul Collar, a National Weather Service meteorologist based in Sullivan.

"There's a lot of things in play when combined that sets up the recipe."

Plus, Lake Michigan is at historic high water levels that will make the possibility of shoreline erosion and flooding even stronger.

One or two rounds of rain are also in Monday's forecast, though temperatures will remain a relatively balmy low 60s in the metro Milwaukee area. Showers and thunderstorms are expected Monday morning and then possibly another bout of rain in the afternoon.

A low-pressure system will push high winds into the area on Monday before moving toward Minnesota's Twin Cities and then wrap around Lake Superior on Tuesday, dropping temperatures.

"That will feel like a slap in the face," said Collar.

Winds are expected to shift to the west, which will lessen waves along Lake Michigan Tuesday. But that also means those winds will funnel colder air down from Lake Superior.

The normal high temperature in southeastern Wisconsin for this time of year is 58, but highs on Tuesday are forecast to be only in the 40s. Add in wind chills from blustery gusts and it will probably feel like mid- to upper 20s.

"There will definitely be a bite in the air," said Collar.