Indiana residents can expect no relief from the heat this week.

Jason Puma, a meteorologist with the National Weather Service in Indianapolis, said changes in weather patterns that could cause a heat wave are not expected until sometime early next week.

Temperatures in the 90s are common in Indiana, Puma said, and so far the weather hasn’t broken any heat records. Later this week, however, temperatures could be in the 90s to 100s, which would flirt with records at that time.

What is causing the heat wave in Indiana?

There is a strong high pressure area over the east coast, said Puma. This could push significantly warmer air from the south and southwest into the Ohio Valley and the Great Lakes region.

“Much of this air came from areas in the American Southwest, where temperatures were around 98 degrees Fahrenheit late last week, and then moved east to where we are,” Puma said.

Patterns keep the air warm in Indiana

This high pressure system works in tandem with what Puma called a “strong ridge axis” in the upper atmosphere. He explained that the atmosphere is like waves on the bottom of a river, with the ridge axis as the highest point.

The back directs the heat in our direction and prevents the high pressure area from moving anywhere.

What needs to be done to break Indiana’s pressure?

Meteorologists like Puma are watching to see if there is a change in the weather pattern where the upper ridge collapses.

“Once that happens, the flow will change from southwest to more westerly or northwesterly. This will help move the high pressure area away and bring cooler air into the region,” Puma said.

Heatwave in Indiana: How to stay safe and comfortable in summer

Will the rain provide some cooling?

Scattered storms on Tuesday and Wednesday, along with expected cloud cover, will keep things a bit cooler, but Puma said Indiana will be mostly dry for the rest of the week.

“However, as we see (Tuesday) and even (Wednesday), there is a warm and moist air mass present,” Puma said. “We can’t rule out a few isolated showers or maybe a thunderstorm here and there.”

NWS Safety Tips for the Heat

Puma advised Indiana residents to limit their outdoor activities to cooler times of the day, especially mornings and evenings.

“If you must be outside during the hottest hours of the day, be sure to take frequent breaks and drink plenty of fluids,” Puma said. “Check on the elderly, children and pets - these are the people and animals who could be most affected by the heat.”

Karl Schneider is an environmental reporter for IndyStar. You can reach him at [email protected]. Follow him on Twitter @karlstartswithk

IndyStar’s environmental reporting project is made possible through the generous support of the Nina Mason Pulliam Charitable Trust.