Triple digits likely Sunday and Monday

Jun. 18—Temperatures as high as 105 degrees are possible in the Rogue Valley on Sunday and Monday, according to the National Weather Service.

The searing forecast has prompted the agency to issue an excessive heat watch for Sunday afternoon through Monday evening.

The watch covers much of Jackson County, including Medford, Ashland, White City, Jacksonville, Ruch, Applegate, Rogue River and Williams. Western Josephine County, including Grants Pass and Merlin, is also included in the coverage area, along with the valleys of western and central Siskiyou County, California, including the Klamath River, Scott and Shasta valleys. This includes the communities of Happy Camp, Mt. Shasta City, McCloud, Dunsmuir, Weed and Yreka.

"Extreme heat will significantly increase the potential for heat-related illnesses, particularly for those working or participating in outdoor activities," a Weather Service bulletin says. "In addition to hot daytime temperatures, overnight temperatures are expected to be unseasonably warm as well.This will provide little relief from the daytime heat, adding to the heat-related stress."

On Friday, the Weather Service estimated a high of 102 degrees Sunday and Monday in Medford, with an overnight low of 69 Sunday. Some cooling is anticipated after Monday, with a high of 92 Tuesday.

"That's because we're going to see some moisture and cloud cover coming in, and maybe even some thunderstorms in the area on Monday, Tuesday and Wednesday," said meteorologist Sven Nilaimischkies.

The best chance for such storms Monday is along the Southern Cascade Range at about Lake of the Woods northward, Nilaimischkies said. Tuesday is the best chance for more widespread activity, he said.

The Saturday forecast calls for sunny weather and a high near 94, with light north-northeast winds. Saturday night is expected to be clear, with a low around 60.

Reach Mail Tribune web editor Ryan Pfeil at 541-776-4468 or rpfeil@rosebudmedia.com. Follow him on Twitter at @ryanpfeil.