NWS: Heat wave looming, storms could help regulate temperatures

With temperatures expected to hit the 90s and dew points in the 70s, “it will make it feel sticky” in the northern part of Illinois this week, a National Weather Service meteorologist said.

But, according to National Weather Service meteorologist Mark Ratzer in Romeoville, there are some complications in predicting how and where the heat and humidity will affect the region, based on the potential for thunderstorms.

Heat in the west – centered now over the “four corners” area of Arizona, Colorado, New Mexico and Utah – is set to expand across the southern plains states and the Midwest by Wednesday, Ratzer said.

But the jet stream may push some of that heat further south, while also kicking up the potential for thunderstorms which may help counterbalance the higher temperatures, he said.

“You may end up getting relatively warm temperatures, but if a thunderstorm complex moves through, it pushes the warm frontal boundary south.”

—  National Weather Service Romeoville Meteorologist Mark Ratzer

“You may end up getting relatively warm temperatures, but if a thunderstorm complex moves through, it pushes the warm frontal boundary south,” Ratzer said.

The week is set to start with highs in the mid-80s on Monday, creeping up closer to the 90s on Tuesday, and the low-to-mid 90s Wednesday through Friday, with the highest temperatures forecast for Thursday.

He does not expect the region to see temperatures over 100 degrees, however.

Ratzer warned again that thunderstorms, particularly those coming from the north and west out of Minnesota, “can change the whole scenario” and prevent some of the highest temperatures from rolling in.

“It is a wait and see kind of thing,” he said.

The forecasted highs and dew points bring “a lot of energy” and the potential some of those thunderstorms could be severe, Ratzer said. What storms could bring by way of wind and rain “is day by day, or a day at a time” and too early to call.

If storms do come through, it doesn’t mean the nights will bring better sleeping temperatures.

“The dew points will be relatively high so it may feel muggy,” Ratzer said.