FXUS65 KBOI 151724
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
1024 AM MST Thu Feb 15 2024

.DISCUSSION...Showers will continue today under a moist and
unstable westerly. Mountains will see heavier showers and
possibly a few lightning strikes this afternoon. While there
will be lulls in the precipitation mountain valleys will see an
additional 3 to 6 inches with higher peaks seeing up to a foot
of additional snowfall through Friday morning. Advisory will
remain in place through the end of the event. Current forecast
is on track for the rest of today.

&&

.AVIATION...Widespread IFR in mountain snow today. Areas of MVFR
in valley rain/mixed precip with snow levels 3500-4500 ft MSL. A
slight chance of a lightning strike after 18Z. 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 after 18Z in SE
Oregon, Magic Valley and south of the Treasure Valley. Winds
aloft at 10kft MSL: W 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.

&&

.PREV DISCUSSION...
SHORT TERM...Today through Saturday night...A shortwave trough
and cold front is crossing our area early this morning.
Meanwhile, satellite imagery reveals a well-defined upper low
over the Olympic Peninsula early this morning. Precipitation
will become showery today as the trough moves east but weak
instability develops within cold air aloft. A few lightning
strikes could develop this afternoon and early evening across
east-central Oregon and west-central Idaho. Westerly flow will
enhance upslope precipitation development across the central
Idaho mountains today, with additional light snow accumulations
above 4000 feet MSL. Expect breezy conditions today, especially
in the higher terrain. Snow levels today into tonight will
remain around 3500-5000 feet, highest near the Nevada border and
lowest in the central Idaho mountains where cold air will
remain trapped in the valleys. Tonight, the upper low over
Washington will move east with precipitation increasing across
the area. Several more inches of snow will fall primarily over
the central Idaho mountains, with rain in the Snake River
Valley. Precipitation will decrease Friday morning as the low
moves southeast. A cold front Friday morning will produce around
a 20% chance for a rain/snow mix in the Treasure and Magic
valleys before ending. Additional snow accumulations of 3 to 6
inches are expected today into tonight in the central Idaho
mountains, with up to a foot above 6000 feet. Elsewhere, a few
inches of snow are possible above 4000 feet, with higher amounts
on the peaks.

Dry conditions will develop Friday afternoon into Saturday as
an upper level ridge moves overhead. However, this will be
short-lived as an upper trough over northern California moves
inland Saturday night. Rain and snow chances will increase to
60-90% across the area by late Saturday night. Snow levels are
likely to remain above valley floors, but there is around a 25%
chance of precipitation starting as snow in the Treasure and
Magic Valleys. Winds will be breezy on Friday in the Magic
Valley, with breezy winds expanding across the area on Saturday
as the next system approaches.

LONG TERM...Sunday through Thursday...Models are in generally good
agreement with the progression of an upper trough that moves through
the area on Sunday. Snow levels range from about 3500-5000 feet with
the highest levels near the Nevada border. Widespread precipitation
is expected. Amounts will be light with snowfall totals of 1 to 3
inches in the mountains. A short-wave upper ridge will bring a
period of dry conditions Sunday night through early Monday.
Southwest flow aloft develops on Monday as a large upper low stalls
off the west coast. The low is expected to weaken as it heads inland
through midweek. There is at least a 30 percent chance of light
precipitation each day with snow levels remaining above valley
floors (>4000 feet). Drier conditions are anticipated on Thursday as
the system exits and weak high pressure aloft develops over the
Pacific Northwest. Temperatures show little day to day change,
averaging around 5 degrees above normal.

&&

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

&&

$$

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DISCUSSION...DG
AVIATION.....SP
SHORT TERM...ST
LONG TERM....BW