Frosty Start, Pleasant Thursday
Southwest Idaho and southeast Oregon will enjoy one more stretch of quiet weather before a wetter pattern develops this weekend.
Mostly clear skies and light winds tonight will allow temperatures to tumble into the upper 20s and 30s across many lower valleys. Patchy frost is possible late tonight into Thursday morning, with Boise dropping to around 34 degrees.
After the chilly start, Thursday looks pretty nice. Clouds will gradually increase, but temperatures should rebound to around 62 degrees in Boise, near or slightly above normal.
Clouds Increase Friday
A weak disturbance will move through the region Friday, bringing more clouds and a chance of showers, primarily across south-central Idaho and the higher terrain.
Snow levels will generally range from 6,000 to 7,000 feet Friday morning, rising toward 8,000 feet during the afternoon. A dusting to a few inches of snow will be possible across the highest peaks and mountain passes, including Banner Summit.
For the Treasure Valley, Friday should remain mostly dry with a high around 61 degrees.
Rain Arrives for Halloween
The bigger weather change comes Saturday as a stronger Pacific storm and cold front move toward the region.
Deep Pacific moisture will push into Southwest Idaho, allowing shower chances to increase through the day. Boise has about a 50% chance of showers Saturday, with a high near 57.
If you're heading out for Halloween Saturday evening, plan on rain and cooler conditions. Rain becomes widespread Saturday night, with the Boise forecast calling for a 90% chance of precipitation and rainfall amounts potentially reaching one-quarter to one-half inch.
An umbrella or waterproof layer may be just as important as the costume.
Cooler Sunday With Mountain Snow
Showers remain likely Sunday morning before gradually tapering off behind the cold front.
Boise will struggle to reach the lower 50s, with a high near 53 degrees.
Snow levels will fall through the weekend, eventually reaching roughly 4,500 to 6,500 feet Sunday afternoon. Most meaningful accumulation should remain above 6,500 feet, where 2 to 5 inches are possible, with locally as much as 7 inches on the highest peaks.
Some snow or a wintry mix could briefly reach elevations near 4,500 feet Sunday, although little accumulation is expected at those lower elevations.
Sunshine Returns Next Week
The storm pulls away Sunday night, opening the door for a quieter stretch of weather.
Monday looks sunny with a high near 56, followed by mostly sunny skies Tuesday and Wednesday. Temperatures slowly climb back toward 60 degrees by the middle of next week.
7-DAY OVERVIEW
- Thursday: Morning frost, increasing clouds, 62°
- Friday: Mostly cloudy, 61°
- Saturday: Showers developing, 57°
- Saturday Night: Rain likely, 90% chance
- Sunday: Morning showers, cooler, 53°
- Monday: Sunny, 56°
- Tuesday: Mostly sunny, 58°
- Wednesday: Mostly sunny, 60°
KEY TAKEAWAY
Enjoy the dry weather through Friday. Saturday turns increasingly wet, with the steadiest rain Saturday evening and night, followed by cooler weather and mountain snow Sunday.
DETAILED EXTENDED FORECAST
Tonight
Patchy frost after 4am. Otherwise, mostly clear, with a low around 34. Light and variable wind.
Thursday
Areas of frost before 9am. Otherwise, increasing clouds, with a high near 62. Light wind.
Thursday Night
Mostly cloudy, with a low around 42. Calm wind.
Friday
Mostly cloudy, with a high near 61. Light wind.
Friday Night
Partly cloudy, with a low around 42. Light east breeze.
Saturday
Mostly cloudy with showers developing, especially later in the day, with a high near 57. A 50 percent chance of showers.
Saturday Night
Showers. Patchy fog after 3am. Low around 41. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Sunday
Showers likely, mainly before noon. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 53. Chance of precipitation is 60%.
Sunday Night
A 20 percent chance of showers before midnight. Partly cloudy, with a low around 34.
Monday
Sunny, with a high near 56.
Monday Night
Partly cloudy, with a low around 36.
Tuesday
Mostly sunny, with a high near 58.
Tuesday Night
Partly cloudy, with a low around 37.
Wednesday
Mostly sunny, with a high near 60.
