The Treasure Valley will enjoy one more warm and beautiful day Saturday before a powerful cold front sweeps through Saturday night, delivering a dramatic temperature drop, gusty winds, and showers to the central Idaho mountains Sunday.
Dramatic temperature changes arrive during the weekend in Scott Dorval’s video forecast
Saturday: Warm and Mostly Sunny with Afternoon Smoke
Saturday will be a warm and mostly sunny day with a high near 86 degrees, running about 5 to 8 degrees above the normal high for mid-September in Boise. Southwesterly flow aloft will tap into warm air and push temperatures well above seasonal averages. However, wildfire smoke from fires in California will be transported northeastward, leading to increasing haziness across southwest Idaho Saturday afternoon. Patchy smoke is expected after 4 p.m.
Pre-frontal pressure gradients will produce gusty southwesterly surface winds, gusting 35 to 45 mph across southeast Oregon and the Snake River Plain down to the Nevada border Saturday afternoon and evening. Residents should secure outdoor furniture and loose items before the front arrives.
Saturday Night: Cold Front Arrives
The primary cold front will push west to east across the area late Saturday evening, with showers and thunderstorms possible north of a Rome-Ontario-Stanley line into Sunday morning. The best chance for showers and thunderstorms will be focused across Baker County in Oregon and central Idaho north of the Snake River Basin. The Treasure Valley will see mostly cloudy skies Saturday night with winds gusting up to 24 mph as the front pushes through.
Sunday: How Much Cooler Will It Feel?
Sunday will feel dramatically different from Saturday. Here is how Sunday’s forecast highs compare to normal for key locations:…