542
FXUS65 KBOI 302020 AAA
AFDBOI

Area Forecast Discussion...UPDATED
National Weather Service Boise ID
220 PM MDT Thu May 30 2024

.SHORT TERM...Tonight through Saturday night...Little change from
previous forecasts. Clear and cool tonight, then sunny and 8-10
degrees warmer Friday as a Pacific upper ridge comes inland.
Increasing clouds from the west  Saturday as a weak Pacific
trough comes inland, but even with clouds Saturday should be
5 degrees warmer than Friday under southwesterly flow aloft.
The incoming Pacific trough will bring a 20-40% chance of
showers to eastern Valley County/ID Saturday evening, and also
a 10-20% chance of thunderstorms, but the rest of our CWA
should stay dry and mostly cloudy as a weak cold front moves
through. The clouds will keep low temps mild Saturday night.
Winds will be light, except for westerly gusts 15-25 mph
Saturday afternoon/evening in southeastern Oregon as the
cold front moves through.

.LONG TERM...Sunday through Thursday...A transiting upper ridge
will bring dry and warm weather to the region on Sunday, with
clouds increasing late in the day. Precipitation spreads into
SE Oregon and w-central Idaho Sunday night as an upper low
approaches the Pac NW coast. Models remain in good agreement on
the track and general timing as the low and accompanying cold
front move through the region on Monday. This system is attached
to a deep sub-tropical moisture tap that will push precipitable
water values into the 95th percentile (around 1.00" across
lower elevations). The current forecast track places the
potential for heavier precipitation over the w-central Idaho
mountains, where there`s a 20-30% probability of an inch or more
of rainfall on Monday. Snow levels for much of this event will
be at or above 10kft MSL, falling to around 8kft MSL Monday
night as the precipitation ends. Thus expect to lose a good
amount of remaining high level snowpack. What doesn`t come off
with the rain on Monday will face building heat as an upper
ridge quickly amplifies over the western US. High temperatures
will push well above normal by Wednesday with lower valleys
likely into the 90s by Thursday (about 15 degrees above normal).
Lower portions of the Snake Plain are still looking at a 10-15%
chance of hitting 100 by Thursday.

&&

.AVIATION...VFR. Scattered cumulus over the e-central Oregon and
w-central Idaho mtns through 02Z this evening, otherwise clear.
Surface winds: W-NW 5-15 kt with gusts 20-30 kt through 03Z this
evening east of KBOI. Winds aloft at 10k ft MSL: W-NW 15-25 kt.

KBOI...VFR. Northwest winds through sunset, then light and variable.

Weekend Outlook...VFR through Sunday. Increased clouds and a slight
chance of showers and thunderstorms in the w-central Idaho mtns,
north and east of KMYL on Saturday. Clouds increase late Sunday with
chance of showers across e-central Oregon in the evening. Winds less
than 10 kt on Friday, becoming W-NW 5-15 kt with local gusts to 25
kt Saturday and Sunday.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

$$

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SHORT TERM...LC
LONG TERM....DG
AVIATION.....DG