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000
FXUS65 KBOI 221604
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
1004 AM MDT Mon Apr 22 2024

.DISCUSSION...Dry westerly flow will continue today with high
clouds at times. A weak ridge will build into the area and bring
warmer temepratures on Tuesday and Wednesday. A weak system over
CA will bring enough instability for showers and thunderstorms
during the afternoon on Tuesday along the NV border and over the
mountains on Wednesday afternoon. Then a trough will develop
and remain over the Western US in the extended period bringing
cooler temperatures and unsettled conditions. Current forecast
on track with no updates.

&&

.AVIATION...VFR with high clouds. Surface winds: W-NW 5-15 kt, with
gusts to 25 kt near KJER KTWF KGNG this afternoon. Winds aloft
at 10kft MSL: W-NW 10-20 kt.

KBOI...Surface winds variable 6 kt or less this morning,
becoming NW 5-10 kt by 18Z.

&&

.PREV DISCUSSION...
SHORT TERM...Today through Wednesday night...West-northwesterly
flow aloft will bring sunny, cool weather today. A low-amplitude
upper ridge in the Pacific will come inland Tuesday bringing
warmer air. Moisture will begin to spread into our CWA from the
south Tuesday for a 10-20 percent chance of showers and
thunderstorms in southern zones late Tuesday and Tuesday evening.
Moisture and instability will increase further Wednesday leading
to a 40 to 70 percent chance of showers and thunderstorms south
of the Snake Basin late Wednesday. Southeast Oregon will also
have a 20 to 40 percent chance of showers and thunderstorms late
Wednesday and Wednesday evening, as will the Boise mountains
and west-central Idaho Mountains. High temps today will be 2 to
4 degrees warmer than yesterday, and another 5 to 8 degrees
warmer Wednesday, then hold steady Thursday. Low temps will be
in the 20s and 30s Tuesday morning but the Idaho agricultural
valleys will stay above freezing. Lows will rise about 8 degrees
Tuesday night, then hold steady Wednesday night.

LONG TERM...Thursday through Monday...A weak upper level trough
will move overhead on Thursday as a stronger trough moves onshore.
Temperatures will cool several degrees from Wednesday, but
remain a few degrees above normal. A 10-50% chance of showers
will develop near the Nevada border and in the higher terrain
with mostly dry conditions elsewhere. As the stronger system
moves inland Thursday night and Friday, precipitation chances
will rapidly increase to 40-90%. As colder air aloft advances
into our area, a 10-20% chance of thunderstorms will also
develop by Friday afternoon. Temperatures will cool several
degrees on Friday to near to slightly below normal. Over the
weekend, the trough will move east, but a deep upper low will
move across the Gulf of Alaska, placing our area in broad upper
level troughing and southwest flow aloft by Sunday or Monday. A
20-60% chance of showers will continue over the weekend into
Monday, with the highest chances each afternoon over the
mountains. Temperatures should rebound a few degrees Sunday and
Monday as southwest flow develops. Snow levels will fluctuate
through the period, but should generally remain above 5500 feet
MSL. Winds will be breezy through the period.

&&

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

&&

$$

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DISCUSSION...KA
AVIATION.....KA
SHORT TERM...LC
LONG TERM....ST