Milwaukee and southern Wisconsin to see heat indices between 100 and 110 degrees this week

The beginning of this week is going to be a hot one.

Milwaukee County is under a heat advisory today , while most of southern Wisconsin's inland counties are under an excessive heat warning. Daytime highs in the low to mid-90s are expected throughout the region, with humidity pushing heat indices close to or at 100 degrees.

Things are expected to remain hot Tuesday, with most of the southern portion of the state currently under an excessive heat watch.

"Tomorrow could be as warm, or perhaps even warmer than today, but the threat is conditional," said Milwaukee-Sullivan National Weather Service meteorologist Benjamin Sheppard. "And what I mean by conditional is we have the potential for some clouds to interfere with those temperatures and make them cooler. But if the skies do remain mostly clear into tomorrow, we could have similar heat indices, up to 110 (degrees)."

Here's what to know about the potentially record-breaking heat.

How hot will it get in Milwaukee this week?

Highs close to 90 degrees are in the forecast Monday for the city of Milwaukee, with temperatures peaking between 1 and 6 p.m. Milwaukee is under an excessive heat watch from 1 to 8 p.m. Heat indices could feel as warm as 94 degrees in the mid-afternoon.

Things are expected to be even warmer further from Lake Michigan. Walworth and Jefferson counties, along with those further west including Dane County, are under an excessive heat warning from 1 to 8 p.m. today. Temperatures in the mid-90s are in the forecast, with heat indices as high as 105 and 106 degrees in some communities, including Madison, Lake Geneva and Janesville.

Most of southern Wisconsin is under an excessive heat watch on Tuesday; this could turn into a heat advisory or excessive heat warning, depending on tomorrow's cloud cover. Currently, a high temperature of 91 is forecasted for Milwaukee, with heat indices over 100 degrees between 2 and 5 p.m.

Temperatures are again expected to be hotter further inland. Heat indices could reach 110 degrees in some south-central Wisconsin communities.

The next two days could potentially be Milwaukee's hottest of the year and even tie daytime temperature records. The city's Aug. 26 record high of 96 degrees was set in 1953, and its Aug. 27 record high of 99 was set in 1973, according to NWS records . Record-setting temperatures are an even greater possibility this week in Madison, Sheppard said, where the Aug. 26 and 27 record highs are 95 degrees ― that's also the forecasted high for Tuesday.

Things are expected to cool down to near-normal across the state by Wednesday after a cold front comes through late Tuesday into Wednesday, Sheppard said. Daytime highs in the low 80s are expected in Milwaukee.

"The winds behind that front in the middle of the day Wednesday are expected to ... turn northeast," Sheppard said. "So, the wind is essentially moving from Lake Michigan over Milwaukee, and that's going to make it feel a lot cooler and be a lot cooler."

Why is it so hot in Milwaukee this week?

There is currently a pattern in the jetstream known as a "ridge," Sheppard explained. A ridge is an elongated area of relatively high atmospheric pressure that brings hot, humid weather.

The ridge is currently positioned directly over Wisconsin. "Essentially what that does is it allows for really warm, really humid air from the South to sit in place in our region, and allows the sun to cook those temperatures up to a really uncomfortable level," Sheppard said.

Will there be storms in Wisconsin this week?

Strong, severe thunderstorms are possible Monday and Tuesday nights throughout southern Wisconsin, though NWS is currently unsure where exactly they'll strike. If storms reach southern Wisconsin on Tuesday evening, hail and strong winds are possible, Sheppard said.

The forecast currently shows about a 30% chance of rain and thunder at 4 p.m. on Tuesday in Milwaukee, climbing to 45% by 7 p.m.

Hot weather safety tips

Hot weather can cause heat-related illness and even death. The Milwaukee Health Department and Centers for Disease Control and Prevention offer these hot weather safety tips:

• Slow down and limit physical activity.
• Spend time in air-conditioned spaces such as shopping malls, movie theaters or libraries.
• Don't leave kids or pets in a parked car. Temperatures can become life-threatening within minutes.
• Wear lightweight, loose-fitting and light-colored clothing.
• Take cool baths or showers. Use wet towels on your skin to cool down.
• Don't rely on fans as primary cooling devices.
• Drink plenty of water.
• Avoid consuming caffeinated or alcoholic beverages, which can increase heat effects.

Wisconsin weather radar

Wisconsin weather warnings

This article originally appeared on Milwaukee Journal Sentinel: Milwaukee and southern Wisconsin to see heat indices between 100 and 110 degrees this week