A strong weather pattern will bring heavy mountain snow, gusty winds, and above-normal temperatures through the week before a broad high pressure system builds in early next week, potentially pushing valley temperatures near 80 degrees by Tuesday.
Wednesday and Thursday: Warming with Mountain Snow
After a slightly calmer day Wednesday, rain and snow will increase across the mountains Wednesday night. Snow levels will start around mountain valley floors where minor accumulations are expected through Thursday morning, with McCall having about a 30% chance of seeing more than an inch of snow through noon Thursday. By afternoon, the warming air mass will raise snow levels to around 6,000 feet.
Up and down temperatures this week lead to massive warming next week
Deeper moisture will transport into northern mountains, resulting in 1 to 1.5 inches of liquid across the southern Wallowas and west-central Idaho mountains. Heavy wet snow above 6,000 feet will bring 8 to 12 inches to higher passes, including Big Creek, Warm Lake, and Banner Summit. Winds will increase Thursday with gusts of 35 to 50 mph across higher open terrain and 25 to 35 mph in lower elevation,s including the lower Snake Plain. Temperatures will be above normal on Wednesday and Thursday, especially across southern zones that remain dry through the period.
Friday Through Saturday: Strong Winds and Continued Mountain Snow
Strong winds will be the headline Friday and Saturday as the polar jet remains over the northern tier of the western United States. The Camas Prairie and ridgetops could see gusts up to 55 mph, and wind advisories or even a high wind warning may be needed across much of the southern zones if this forecast trend continues. The Treasure Valley and Upper Weiser Basin will likely be the most sheltered from the strongest winds.
Heavy moisture will stay to the north, but portions of northern Valley County and Baker County will see valley rain and mountain snow through Saturday. High summits and mountain passes could see moderate accumulations of wet snow, while populated areas below about 6,000 feet will see minor accumulations. Saturday looks to be the wettest day of the period with a 70% chance of rain, mainly before noon.
Early Next Week: Near-Record Temperatures
A broad high pressure system will build in beginning early next week, bringing a dramatic warmup to the region. Temperatures will climb through the weekend into next week, with the Upper Treasure Valley and Magic Valley potentially seeing highs in the 70s and near 80 degrees by Tuesday - a 25 to 40% chance of near-record high temperatures for this time of year. Light mountain showers will likely continue over the west-central and Boise mountains through Monday, with dry conditions expected elsewhere.
Mountain Snow Conditions for Ski Areas
This week's storm will deliver significant snowfall to higher elevation ski areas, with 8 to 12 inches of heavy wet snow expected above 6,000 feet at higher passes. However, the wet nature of the snow reflects the warm temperatures, and the rapid warmup heading into next week will significantly impact snow conditions at lower elevation resorts. Higher terrain should maintain better conditions through the weekend before the near-record warmth takes hold.
Tonight
Partly cloudy, with a low around 31. Diminishing NW breeze.
Wednesday
Partly sunny, with a high near 56. SSE wind 5 to 7 mph.
Wednesday Night
A 20 percent chance of rain. Cloudy, with a low around 45. Wind SE 5 to 7 mph.
Thursday
A 20 percent chance of rain. Cloudy, with a high near 63. West wind 5 to 15 mph, with gusts as high as 25 mph.
Thursday Night
A 20 percent chance of rain before midnight. Mostly cloudy, with a low around 47. NW wind 6 to 13 mph.
Friday
A 30 percent chance of rain, mainly before noon. Mostly cloudy & milder, with a high near 65.
Friday Night
A 50 percent chance of rain. Cloudy, with a low around 48.
Saturday
Rain likely, mainly before noon. Mostly cloudy and breezy, with a high near 58. Chance of precipitation is 70%.
Saturday Night
Mostly cloudy, with a low around 35.
Sunday
Mostly cloudy & seasonable, with a high near 55.
Sunday Night
Mostly cloudy, with a low around 40.
Monday
Mostly cloudy & milder, with a high near 67.
Monday Night
A 20 percent chance of rain. Mostly cloudy, with a low around 46.
Tuesday
Partly sunny & unseasonably warm, with a high near 74.
