A cold front advancing eastward across Oregon will bring widespread showers to the region tonight before a significant warming trend delivers temperatures 10 degrees above normal and highs reaching 91 degrees by the weekend.
Cold front brings showers & cooling ahead of late-week warming in Scott Dorval's video forecast
Ahead of the front, a very dry air mass is in place with humidity values near 10 percent through much of the Snake River Plain, accompanied by winds gusting to 20 to 30 mph. Scattered to widespread showers will develop through this evening, first across central Oregon, reaching the Treasure Valley after around 9 p.m. Although coverage will be high, rainfall amounts and intensity will be limited by how dry the sub-cloud layer is. Precipitation totals are generally expected to range between 0.10 and 0.25 inches across the Snake River Plain, and up to 0.25 to 0.50 inches in the Idaho mountains.
By Tuesday morning, the cold front will advance eastward, but a more unstable air mass will support isolated thunderstorm development over the central Idaho mountains, especially over Valley County. Breezy conditions will occur from southeast Oregon into southern Idaho, with wind gusts approaching 30 to 40 mph during the afternoon. Temperatures will be 5 to 10 degrees below normal through Wednesday.
Near-freezing temperatures are possible Wednesday and Thursday morning in parts of southeast Oregon, including Burns and Baker City, and higher elevation valleys in Idaho, including McCall and the Camas Prairie. A dusting of snow is also possible across the mountains of Valley County as snow levels fall to around 5,800 feet.
An upper-level ridge will then build over the Pacific Northwest, bringing dry weather and a significant warming trend. Temperatures will be near normal on Thursday before warming to around 10 degrees above normal through the upcoming weekend. Highs will reach 91 degrees Saturday through Monday under mostly clear skies with light and variable winds.
Tonight
Showers and possibly a thunderstorm, mainly before 3am, then a chance of showers and thunderstorms after 3am. Low around 52. Gusty breezes settle down overnight. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday
Partly sunny, then gradually becoming sunny, with a high near 74. Wind becoming NW 10-15 mph in the morning. Winds could gust as high as 25 mph.
Tuesday Night
Mostly clear, with a low around 47. NW wind 5-10 mph, with gusts as high as 25 mph.
Wednesday
Sunny, with a high near 71. Northwest wind 10-15 mph, with gusts as high as 26 mph.
Wednesday Night
Clear, with a low around 44. Diminishing wind.
Thursday
Sunny & warmer, with a high near 80.
Thursday Night
Clear, with a low around 52.
Friday
Sunny & warm, with a high near 89.
Friday Night
Clear, with a low around 57.
Saturday
Sunny and hotter, with a high near 91.
Saturday Night
Clear, with a low around 56.
Sunday
Sunny and hot, with a high near 91.
Sunday Night
Mostly clear, with a low around 59.
Monday
Sunny and hot, with a high near 91.
