textproduct: Boise

KEY MESSAGES

- Dry through Thursday, with near normal temperatures.

- Precipitation chances increasing across higher terrain Friday afternoon. Becoming widespread Saturday afternoon.

- A drying and warming trend will set in Monday, through at least midweek.

SHORT TERM /Through Friday Night/

Following the departing shortwave, a drying and clearing trend will continue this morning. These clearing skies will allow for good radiational cooling; which, when combined with the recent precipitation, will allow for the development of fog/freezing fog this morning (especially in sheltered valleys). Temperatures this afternoon will generally be in the 50s in the low elevations, and 40s in the Oregon high desert and higher Idaho Basins. As flow aloft backs to be out of the southwest, thanks to a deepening low off the west coast, a warming trend will set in Thursday afternoon (highs around 5 degrees warmer than today). Before this, clear overnight skies tonight allow for cooler low temps. The majority of lower elevations will reach near or below freezing Thursday morning, with lows of 10-20 degrees in the Oregon high desert and higher Idaho basins.

A weak shortwave rotating through this low will bring an increase of high cloud cover Thursday. Another consequence of this shortwave will be increasing precipitation chances early Friday over the central Idaho mountains. The southwesterly flow aloft will keep snow levels high and snow accumulations low, with a dusting to an inch of snow expected above 6kft.

LONG TERM /Saturday through Wednesday/

As the shortwave in the short-term period departs, the main low will begin moving its way through our area. This trough will have a good pull of Pacific moisture ahead of it, with precipitable water values increasing to around the 90th percentile in southwest Idaho. The better juxtaposition of forcing and moisture will fall over southwest Idaho, which will lead to increasing precipitation chances through the day Saturday, reaching 50-80% Saturday evening and night as a cold front crosses the area. That being said, an umbrella may be a fine addition to your Halloween costume. Snow levels will initially begin at 6-8 kft MSL, lowering to 4.5-6.5 kft MSL by Sunday afternoon. These lowering snow levels will coincide with decreasing precipitation chances as conditions dry out behind the front. Overall, the bulk of any snow accumulation will remain above 6.5 kft MSL, with generally 2-5 inches of accumulation (Locally up to 7 on the highest peaks). The lowering snow levels could allow for snow or wintry mix as low as 4.5 kft Sunday, although little accumulation is anticipated as precipitation tapers off behind the departing system. Ridging will build in behind the departing system, allowing for dry conditions Monday afternoon through at least mid- week. Temperatures will be seasonable or below normal throughout the period.

AVIATION /06Z Wednesday through Thursday/

Issued 1139 PM MDT TUE OCT 27 2026

Generally VFR. Localized LIFR/IFR conditions with patchy freezing fog and low clouds in high elevation valleys near KBNO-KMYL-KBKE. Mountains obscured in fog and low clouds. Surface winds: variable less than 10 kt through morning, then SW-SE 5-15 kt by early PM. Winds aloft at 10kft MSL: SW 20-30 kt.

KBOI...VFR. Low clouds lingering by the foothills. Clearing skies by the early morning. Surface winds: E-SE 5-10 kt tonight then variable less than 6 kt by the late morning.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.