FXUS65 KBOI 140932
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
332 AM MDT Sat Sep 14 2024

.SHORT TERM...Today through Monday night...Southwest flow aloft
will maintain the dry conditions today, along with slightly
above-normal temperatures and light winds. An developing upper
low near the British Columbia coast is forecast to move
southward along the PacNW coast on Sunday, then inland -
reaching the Great Basin (centered over Nevada) on Monday.
Southerly flow will bring an increase in moisture ahead of the
low on Sunday. Initially, the best chances for precip will be in
SE Oregon, but as the low moves inland, the precip spreads into
SW Idaho late Sunday into Monday. Showers are likely (> 60
percent chance) across most of SE Oregon and all SW Idaho late
Sunday night through Monday night. However, the latest model
runs have shifted the track further south than previous runs,
which lowers the chance of precipitation across portions of SE
Oregon from Burns to Baker City. There is also some support for
at least a slight chance (15-25 percent) of thunderstorms. This
is an unusually moist and dynamic system which has implications
on heavier rainfall rates, especially in locations that receive
any thunderstorms. The potential for excessive rainfall will
need to be monitored, especially on recent burn scars.

.LONG TERM...Tuesday through Saturday...There are some timing
differences with regard to the track of the upper low, but
generally agree that the low will move northeast across
southern and eastern Idaho on Tuesday. Widespread (> 80 percent
coverage) showers, along with at least a slight chance of
thunderstorms, will continue near the low - including SW Idaho
and far eastern Oregon. There remains a concern for excessive
rainfall, especially on the burn scars. Another upper low
develops over the PacNW late Tuesday that tracks further west
and south than the previous one. The chance for showers
continues through Thursday as the low moves through Nevada,
mainly in central Idaho and in our southern areas near the
Nevada border. Models then diverge significantly with regard to
the strength of a third system that moves across the northern
Rockies to our east late in the week. Precip chances will be
limited to less that 20 percent in SW Idaho. Temperatures
average 10-15 degrees below normal through the week with valley
highs only in the 60s to lower 70s.

&&

.AVIATION...VFR. Mostly clear skies. Surface winds: variable
less than 10 kt. Winds at 10kft: SW 10-20 kt.

KBOI...VFR. Surface winds: SE 5-10 kt becoming north around 5
kt after 21Z.

Sunday Outlook...Increasing clouds. Local MVFR in showers, and
slight chance of thunderstorms mainly SE Oregon Sunday
afternoon and evening. Winds variable less than 10 kt, becoming
mainly northwest 5-15 kt during the afternoon.

&&

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

&&

$$

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SHORT TERM...BW
LONG TERM....BW
AVIATION.....BW