FXUS65 KBOI 152128
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
228 PM MST Thu Feb 15 2024

.SHORT TERM...Tonight through Saturday night...An upper low
along the WA coast will track inland overnight before kicking
east of the area on Friday. Precipitation will continue out
ahead of the low tonight, with westerly flow enhancing
development in the mountains. Marginal instability and afternoon
heating/energy could support development of heavier graupel
showers or possibly a thunderstorm before the threat diminishes
this evening. Showers could also produce gusty winds to 45 mph
through early evening. Snow levels will run between 4-5kft MSL
overnight, dropping on Friday with passage of the low. While
precipitation could mix with snow in the Snake Plain Friday
morning, temperatures will be too warm for any accumulation
concerns. Mountain valleys will see an additional 1-4 inches
overnight with higher amounts above valley floors. By Friday
afternoon most areas are dry with a lingering chance of showers
over s-central Idaho. Passage of an upper ridge will bring dry
weather for Friday night into early Saturday. The ridge moves
east on Saturday in advance of an upper trough moving into the
Pac NW. Light precipitation will overspread SE Oregon late in
the afternoon, advancing into SW Idaho Saturday night. Snow
levels will start between 3-5kft Saturday night, and a mix of
rain and snow is possible in lower valleys. Though similar to
Friday morning, temperatures will be too warm for accumulation
below 4kft MSL. Temperatures through Saturday will be slightly
above normal.

.LONG TERM...Sunday through Thursday...A shortwave trough will
exit the region Sunday afternoon, taking precipitation with it.
Ridging aloft will pass by rapidly Sunday night, and by Monday
afternoon we will be under strong southwest flow. This will
bring warm moist air into the region, setting the stage for a
snowy/rainy period Monday through Wednesday. Models diverge on
the potential for the passage of a trough late Wed-Thu, and
uncertainty in the forecast is therefore high. For now, NBM
gives us a relatively low chance (5- 20%) of precipitation Wed
night and Thu. Snow levels will be fairly high during the long
term period, averaging 4000-5000 ft MSL, and therefore snow will
be confined mainly to the mountains. Temps will run around 5
degrees above normal.

&&

.AVIATION...Widespread IFR in mountain snow through tonight.
Areas of MVFR in valley rain/mountain snow, with snow levels
4000-5000 ft MSL. There's still a slight chance of a lightning
strike through the afternoon and evening. Mountains obscured.
Surface winds: SE-SW 5-15 kt at TAF sites, 10-20 kt south and
southeast of KBNO. Gusts of 20- 30 kt in SE Oregon, Magic Valley
and south of the Treasure Valley through 16/03Z. Winds aloft at
10kft MSL: W to NW 25-35 kt.

Weekend Outlook...Precipitation moving out of the area Friday,
then dry with mostly VFR conditions Friday night.
Precipitation moves back in from the west Saturday. Widespread
MVFR and areas IFR conditions accompanying rain and snow
Saturday through Sunday. Snow levels 3500-5000 ft MSL. Mountains
obscured. Conditions improving west to east late Sunday.
Surface winds generally NW 5-15 kt on Friday, becoming SE-E
10-20 kt Saturday, then SW-SE Sunday.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 5 AM MST Friday IDZ011-013.
OR...None.

&&

$$

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SHORT TERM...DG
LONG TERM....SP
AVIATION.....SP