After a wet and active Friday, showers will taper off tonight and Saturday morning before high pressure rebuilds and delivers a stunning fall weekend with sunny skies and temperatures climbing to the low 80s Sunday and the upper 80s to near 90 degrees by late next week.
Showers taper off in time for a beautiful warming weekend in Scott Dorval's video forecast
Tonight and Saturday Morning: Lingering Showers
Showers and thunderstorms will continue tonight, mainly before 1 a.m., with a 40 percent chance of precipitation. Fog is likely in the late overnight to early morning periods tonight and Saturday morning, especially in areas that received heavy rainfall today. Showers will continue through Saturday afternoon as moisture wraps around the eastward-moving low-pressure center, with a 30 to 50 percent chance of showers and a lower 10 to 15 percent chance of thunderstorms Saturday morning.
Flash Flood Concerns: Central Idaho Mountains
Significant rainfall has occurred across the central Idaho mountains today, with totals exceeding 2 inches southeast of Glenns Ferry and a small area recording over 3 inches from training thunderstorms. A Flash Flood Watch has been issued in the Boise Mountains for burn scars in the area. Anyone in or near these burn scar areas should monitor conditions closely and be prepared to move to higher ground if additional heavy rain develops.
Weekend Outlook: Outstanding Fall Conditions
Behind the low, high pressure will return as a ridge axis moves over the region, leading to rapidly improving and warming conditions late Saturday and through Sunday.
Saturday afternoon: Mostly cloudy skies will gradually give way to sunny conditions with a high near 78 degrees. A pleasant afternoon with improving conditions.
Sunday: Sunny skies and a high near 82 degrees, running about 5 degrees above normal. One of the finest fall days of the season.
Monday and Tuesday: Sunny skies and highs near 84 degrees. The warmth continues into the new work week.
This weekend's conditions will be exceptional for outdoor activities across the Treasure Valley and central Idaho mountains:
- Outdoor festivals and community events: Sunday through Tuesday will be picture-perfect with sunny skies, temperatures in the low to mid-80s, and light winds.
- Hiking and trail running: The Boise Foothills and surrounding areas will be spectacular. The recent rainfall has dramatically improved trail conditions and fall colors are beginning to emerge.
- Fall foliage viewing in the central Idaho mountains: This weekend will be an outstanding time to visit the Sawtooth Valley, Payette River corridor, and the mountains around McCall. This week's significant rainfall will further enhance the fall color change, and temperatures in the mountains will be comfortable in the mid to upper 60s Saturday and climbing to the low 70s Sunday and Monday.
- Golf and cycling: Near-perfect conditions Sunday through Tuesday with sunny skies and temperatures in the low to mid-80s.
The official start of astronomical fall, the autumnal equinox, arrives on Tuesday, September 22 at 8:29 p.m. MDT. The Treasure Valley will be celebrating the first full day of fall Wednesday under sunny skies and a high near 86 degrees.
Looking Ahead: Warming Trend Continues
An upper-level ridge over the Intermountain West and Rocky Mountains will remain the dominant weather feature through the extended period. Temperatures will hold steady at about 5 degrees above normal Monday and Tuesday before the ridge amplifies as a strong Alaskan low-pressure system approaches the Pacific Northwest. This will bring well above-normal temperatures Thursday and Friday, with highs running 5 to 10 degrees above seasonal normals and temperatures reaching the upper 80s to near 90 degrees in the lower valleys.
Tonight
A 40 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 54. North wind 5 to 7 mph becoming calm in the evening.
Saturday
Mostly cloudy, then gradually becoming sunny, with a high near 78. Calm wind becoming west northwest 5 to 8 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 54. Northwest wind around 5 mph becoming calm in the evening.
Sunday
Sunny, with a high near 82. Light and variable wind becoming west southwest around 5 mph in the afternoon.
Sunday Night
Mostly clear, with a low around 56.
Monday
Sunny, with a high near 84.
Monday Night
Partly cloudy, with a low around 57.
Tuesday
Mostly sunny, with a high near 84.
Tuesday Night
Mostly clear, with a low around 57.
Wednesday
Sunny, with a high near 86.
Wednesday Night
Mostly clear, with a low around 58.
Thursday
Sunny, with a high near 89.
Thursday Night
Partly cloudy, with a low around 61.
Friday
Mostly sunny, with a high near 86.
