Critical fire weather conditions are ongoing across parts of Idaho and Oregon this afternoon as hot, dry, and windy conditions combine with a cold frontal passage this evening, before temperatures swing dramatically between 10 degrees above normal and slightly below normal through the weekend.
High Fire Danger through 9pm Wednesday then cooler Thursday in Scott Dorval's video forecast
Hot temperatures near 90 degrees have been observed in the Upper and Lower Treasure Valleys today. Red Flag Warnings remain in effect for the Owyhee Mountains and the Magic Valley, where single-digit relative humidity values have been recorded near the Nevada border. Wind gusts will increase this evening and shift to the west, especially in the Lower Snake River Plain.
Light showers and overcast skies are covering most of southeast Oregon and high terrain in southern Idaho. Isolated thunderstorms with less than a 20 percent chance will continue over northeastern Oregon and the West Central Mountains, with virga showers over southwest Idaho. Little to no rain is anticipated from these showers. Any stronger showers or storms that develop could bring outflow wind gusts up to 40 mph with blowing dust, though current forecast confidence keeps that threat further to the northwest.
Temperatures will cool off Thursday by about 5 to 10 degrees, with highs in the upper 70s to low 80s expected in the lower elevations. As a ridge of high pressure quickly rebuilds over the region, temperatures will rebound back to about 10 to 15 degrees above normal on Friday with very dry conditions. A strong upper-level low over the Pacific will move onshore late Friday, bringing breezy conditions to southeast Oregon and the Snake River Valley on Friday afternoon into the evening.
A trough will move over the Pacific Northwest on Saturday and Sunday, bringing breezy conditions and cooler temperatures. Southwest Idaho and southeast Oregon will remain in the dry slot with this system. Temperatures will cool around 15 degrees from Friday to around 5 degrees below normal Saturday and Sunday. Another system is expected to move into the Pacific Northwest Monday through Wednesday, with increasing chances of precipitation and cooler temperatures likely in subsequent forecasts.
Tonight
Mostly cloudy, then gradually becoming clear, with a low around 54. NW wind at 15 mph with gusts as high as 24 mph then diminishing late.
Thursday
Sunny, with a high near 81. NW wind 5-10 mph.
Thursday Night
Mostly clear, with a low around 53. NW wind 5-10 mph becoming calm in the evening.
Friday
Sunny and hotter, with a high near 90. Light wind.
Friday Night
Mostly clear, with a low around 54. Light wind.
Saturday
Mostly sunny and becoming windy late in the day and evening, with a high near 75.
Saturday Night
Mostly clear, with a low around 46.
Sunday
Sunny & pleasant with a cool morning, with a high near 74.
Monday
Mostly sunny & warmer, with a high near 83.
Tuesday
Partly sunny, with a high near 82.
Wednesday
A 20 percent chance of showers otherwise mostly sunny, with a high near 79.
