A few showers before skies clear tonight
A weak disturbance crossing the region Tuesday will keep isolated showers around, mainly across the higher terrain and northern mountains. precipitation will remain light, although minor snow accumulation is possible above 6,000 feet.
Any lingering showers will quickly fade this evening as the disturbance moves away. Skies will gradually clear overnight, with temperatures falling into the 30s across many lower valleys.
Frost becomes the midweek weather story
Wednesday will be quiet, sunny and cool, with Boise reaching around 58 degrees. Temperatures remain about 5 degrees below normal across the region.
The bigger concern comes overnight. Clear skies and light winds will allow temperatures to drop into the lower and middle 30s in many lower valleys, with freezing temperatures possible in colder, higher valleys.
Patchy frost is possible early Wednesday, with another round expected early Thursday. Thursday morning may actually offer better conditions for frost formation thanks to mostly clear skies and light winds.
For Boise, temperatures fall to around 34 Wednesday night with widespread frost possible early Thursday.
Thursday brings a brief warm-up
After the cold start, Thursday should be the warmest and one of the nicest days of the week. Boise reaches around 62 degrees under mostly sunny skies as a weak ridge moves overhead.
Most lower elevations stay dry into Thursday night, although moisture arriving from the south could produce a few light showers across the central Idaho mountains late Thursday.
The pattern changes Friday
Clouds increase Friday as a much larger Pacific weather system begins influencing the Northwest. Boise remains relatively mild with a high around 60 degrees.
Rain chances will initially be modest Friday into Saturday, with the greatest chances over the mountains. Snow levels generally remain between 5,000 and 7,000 feet during this period.
The more significant change arrives later Saturday.
Saturday evening turns wetter
Anyone with outdoor plans Saturday evening will want to keep an eye on the forecast.
Rain chances increase sharply Saturday evening, reaching roughly 40% to 70% across the region as the approaching storm pulls moisture into Southwest Idaho. Boise currently carries a 40% chance of showers Saturday, increasing to 60% Saturday night.
Temperatures will also begin falling as the system approaches.
Colder air and lower snow levels Sunday
The main cold front is expected to move through early Sunday morning.
Behind it, cooler air spreads across the region, dropping Boise's Sunday high to around 54 degrees. Snow levels fall to roughly 4,000 to 6,000 feet Sunday morning.
Snow is likely at some higher mountain elevations, particularly above 5,000 feet, with at least a chance of snow reaching elevations near 4,000 feet as colder air arrives.
By Monday, snow levels could fall to around 3,500 to 4,500 feet, although precipitation will already be decreasing.
Drier weather returns next week
The storm pulls away Sunday night, allowing drier weather to return. Boise falls to around 33 degrees Sunday night before sunshine returns Monday with a high near 55.
Temperatures should remain seasonable to slightly below normal heading into the beginning of next week.
Tonight
Mostly cloudy during the early evening, then becoming mostly clear, with a low around 38. Light wind.
Wednesday
Patchy fog between 9am and 10am. Otherwise, sunny, with a high near 58. Light wind.
Wednesday Night
Patchy frost after 3am. Otherwise, mostly clear, with a low around 34. Light wind.
Thursday
Widespread frost, mainly before 7am. Otherwise, mostly sunny & milder, with a high near 62. Light wind.
Thursday Night
Mostly cloudy, with a low around 42. Light and variable wind.
Friday
Mostly cloudy, with a high near 60.
Friday Night
Partly cloudy, with a low around 38.
Saturday
A 40 percent chance of showers, mainly after noon. Partly sunny, with a high near 58.
Saturday Night
Showers likely, mainly after midnight. Patchy fog after 2am. Otherwise, mostly cloudy, with a low around 40. Chance of precipitation is 60%.
Sunday
A 50 percent chance of showers. Patchy fog before 10am. Otherwise, mostly cloudy, with a high near 54.
Sunday Night
Patchy fog. Otherwise, mostly clear & cold, with a low around 33.
Monday
Patchy fog. Otherwise, sunny, with a high near 55.
Monday Night
Partly cloudy, with a low around 36.
Tuesday
Mostly sunny, with a high near 59.
