A well-defined cold front is pushing through the region this evening, bringing gusty winds, isolated thunderstorms, and a sharp drop in temperatures that will lead to subfreezing mornings across agricultural areas through Saturday.
Cold Front Brings Storms and Wind Tonight
The cold front will push across southwest Idaho this evening. Showers and isolated thunderstorms will develop ahead of the front, with enhancement possible as it pushes into the west-central Idaho mountains. The wind gust potential along the front is 30 to 40 mph, with higher-end gusts up to 50 mph possible from stronger showers and storms.
Colder air will quickly move in behind the front tonight, allowing precipitation to change over to snow down to the valley floors. This will mostly impact the western Magic Valley, where showers will linger into Thursday morning. Otherwise, lower elevations will dry out behind the front overnight while mountains see a continued chance of snow showers.
Light accumulations of 1 to 3 inches are expected across mountain valleys through mid-morning Thursday, while higher elevations will pick up an additional 3 to 8 inches of snow.
Scott Dorval's video forecast highlights when you will see freezing temperatures
Freeze Warning Issued for Thursday Morning
In the Snake River Plain, temperatures will drop to around freezing Thursday morning, prompting the issuance of a Freeze Warning. The highest confidence for freezing temperatures is across the Upper Treasure Valley (Boise metro and points east) and the western Magic Valley. There is less certainty about a freeze in the lower Treasure Valley, where continued northwest winds could keep temperatures just above freezing, especially near the Idaho-Oregon border.
Friday Brings a Harder Freeze and Chilly Winds
Friday will be notably cooler, with high temperatures running about 15 degrees below normal. Breezy northwest winds will make it feel even colder; wind chill values in the warmer spots of the lower Snake Plain will only top out in the mid-30s to low 40s.
With the cold air mass firmly in place, there is much higher confidence in widespread freezing temperatures Friday morning across the entire Snake River Plain. This will be a colder and longer-duration freeze than what is expected tonight. Otherwise, Friday will be dry across most of the area, with only scattered snow showers lingering in the west-central Idaho mountains.
Another frost or freeze is possible Friday night into Saturday morning, though no official warnings have been issued for that period yet.
Weekend Warming Trend Before Next System
A ridge of high pressure building into the Northwest will bring warmer and drier conditions Saturday and Sunday. While Saturday morning will still see temperatures hovering near freezing in the lower Treasure Valley and 5 to 10 degrees below freezing in other areas, afternoon highs will rebound nicely. By Sunday, peak temperatures are expected to reach 5 to 10 degrees above normal, with highs in the mid-70s.
The warming trend will continue into Monday, with highs approaching the upper 70s. However, another weather system from the Gulf of Alaska is expected to arrive early next week. While the exact timing remains uncertain, precipitation chances will increase to 20 to 40 percent area-wide by Tuesday and Wednesday, accompanied by breezy south to southwest winds.
Tonight
Rain showers, possibly mixing with snow after midnight, then gradually ending. Some thunder is also possible. Low around 32. NW wind 10-15 mph, with gusts as high as 26 mph during the evening. Chance of precipitation is 90%. Little or no snow accumulation expected.
Thursday
A slight chance of snow showers before 7am, then a chance of snow showers after 11am. Partly sunny, blustery & chilly with a high near 47. NW wind 5 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 40%. Little or no snow accumulation expected.
Thursday Night
Mostly clear, with a low around 28. Diminishing wind with frost & freeze conditions overnight.
Friday
Sunny & cool, with a high near 54. Wind NW 5-8 mph.
Friday Night
Mostly clear & still cold, with a low around 33.
Saturday
Mostly sunny & milder, with a high near 64.
Saturday Night
Partly cloudy, with a low around 41.
Sunday
Mostly sunny & very pleasant, with a high near 74.
Sunday Night
Mostly cloudy, with a low around 47.
Monday
Mostly sunny & unseasonably warm, with a high near 77.
Monday Night
Partly cloudy, with a low around 49.
Tuesday
Mostly sunny & pleasant, with a high near 74.
Tuesday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 47.
Wednesday
A slight chance of showers. Mostly cloudy, with a high near 64.
