182
FXUS65 KBOI 201140 CCA
AFDBOI

Area Forecast Discussion...CORRECTED
National Weather Service Boise ID
334 AM MDT Sun Apr 20 2025

.SHORT TERM...Today through Tuesday night...Mostly sunny and
becoming breezy today ahead of another approaching weak north
Pacific cold front, expected to reach our CWA late today. At
3 AM MDT the front was barely evident on IR satellite imagery,
extending from southern BC to near Astoria/OR then into the
Pacific. The front should become better defined later today
with scattered showers (30-40 percent areal coverage) as the
supporting upper trough slowly deepens along the nw coast
before moving into our CWA tonight. Cooling aloft will cause
enough destabilization for isolated thunderstorms (10-15
percent areal coverage) in Idaho south of the Snake River this
afternoon.  Skies will remain mostly cloudy tonight then clear
from the west Monday.  Temps will lower about 5 degrees Monday,
and west or northwest winds will gust to 35 mph in south-central
Idaho Monday afternoon, with lighter northwest winds (10-20 mph)
elsewhere in our CWA.  Temps will warm 2-4 degrees Tuesday after
the upper trough exits east. Latest models then show another
upper trough forming over WA and OR Tuesday night, leading to
weak frontogenesis and a slight chance of rain showers in
southwest Idaho overnight into early Wednesday. Total rainfall
today through Monday will be only around .10 inch in Owyhee and
Twin Falls Counties, and in Valley County, ID. Snowfall up to
one inch is also possible in the west-central Idaho mountains
above 5500 feet MSL.

.LONG TERM...Wednesday through Sunday...Dry and seasonable
conditions Wednesday/Thursday, as an upper level ridge builds
over the region. While uncertainty remains regarding timing and
precipitation amounts, model ensembles are in good agreement of
an upper level trough moving from the Pacific into our area
Friday. As a result, chances for precipitation are raised
Friday afternoon through Sunday. Precipitation chances Friday
afternoon through Sunday range from 15-50%, with the highest
chances found in the West-Central Mountains. Breezy northwest
winds return over the weekend following a cold frontal passage.
Temperatures will warm from around normal on Wednesday to 5-10
degrees above normal Thursday/Friday, dropping back down to
around normal come Saturday and Sunday.

&&

.AVIATION...VFR today. Showers developing This afternoon/evening,
mainly over the ID West-Central Mtns and South Central ID. There
is a low (10-20%) chance of thunderstorms developing this
afternoon over the western Magic Valley and Southern Highlands.
MVFR conditions possible in thunderstorms. Mountains obscured
in precipitation. Snow levels 5.5-6.5 kft MSL. Surface Winds:
Variable under 10 kt this morning, becoming W-NW 10-20 kt this
afternoon. Winds aloft at 10kft: W-NW 15-25 kt.

KBOI...VFR. Surface winds variable less under 10 kt, becoming
NW 10-15 kt this afternoon.

&&

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

&&

$$

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SHORT TERM...LC
LONG TERM....NF
AVIATION.....NF