A stretch of unseasonably cool weather should begin a turnaround today, with forecasters predicting temperatures in Central Oregon into the 80s and headed toward the upper-90s by early next week.

Forecaster Mike Vescio, with the National Weather Service office in Pendleton, said a weather system that’s been generating record high temperatures in Nevada and Arizona in recent days has begun shifting northward.

Most of Central Oregon is expected to see highs around 85 today, close to 90 on Friday and well above 90 into the middle of next week.

Higher elevations are unlikely to be significantly cooler. At various locations around the Cascade Lakes Highway, highs are forecast in the mid-to upper-80s from Friday through next Wednesday, the result, Vescio said, of warm air carried aloft on high-altitude currents.

“Very few places are going to see relief from the heat,” he said.

The hottest locations across the region are expected to be far southeastern Oregon and the Columbia River Basin in both Oregon and Washington, although all parts of both states are likely to see above-average temperatures. The Tri-Cities area could reach 108 by early next week, Vescio said.

Forecasts show the region approaching near-record temperatures on Monday and Tuesday, when all of Central Oregon’s population centers are expected to top 95 degrees.

Longer-term forecasts suggest marine air may begin moving onshore next Thursday, Vescio said, dropping temperatures down closer to the historic average.

For a full weather report, see Page B6.