489
FXUS65 KBOI 231518
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
918 AM MDT Mon Sep 23 2024

.DISCUSSION...Cirrus clouds coming in from the northwest as a
warming Pacific upper ridge builds inland. The ridge will move
over our CWA Tuesday and east of us Wednesday. Wednesday will
be the warmest day with highs now forecast 90 to 93 degrees in
the Treasure Valley, 80s in other valleys and basins, and 70s
in the mountains. A cold front Wednesday evening looks strong
enough for a 10-20 percent chance of thunderstorms north of
Baker/OR- McCall/ID. Current forecast has all this. No updates.

&&

.AVIATION...VFR. High clouds will diminish late Monday. Surface
winds: Becoming mostly NW 5-15kt with afternoon gusts to 25kt
east of KMUO. Light and variable overnight. Winds at 10kft MSL:
North-northeast at 10-15kt.

KBOI...VFR. Scattered to broken cirrus. Light winds this morning
becoming northwest 5-15kt this afternoon.

&&

.PREV DISCUSSION...
SHORT TERM...Today through Wednesday night...A dry weak cold
front will finish moving through the area this morning, ushering
in increasing NW winds by this afternoon, especially from
around Mountain Home east toward Twin Falls and Jerome. An upper
level ridge will build over the region tonight and then move
quickly off to the east Tue and Tue night. This will allow dry
and warmer SW flow aloft to move in. Temps will warm each day,
reaching a peak Wed with readings around 15 degrees above
normal. There may be enough moisture by Wed night for showers
and thunderstorms across the north, and the forecast PoP is
trending slowly upwards in/near Baker County. This latest
forecast has values of 5-20% there, mainly Wed evening.
Otherwise, the short term period is dry. After the previously
mentioned increase in NW winds this afternoon, winds will be
fairly light Tuesday. However, Wed will bring an increase in SW
winds across much of SE Oregon, Owyhee County, and the higher
elevations of our Idaho mountains.

LONG TERM...Thursday through Monday...Dry southwest flow aloft
will remain over the region Thu through Sat night. A shortwave
trough is likely to move through Sun, but models differ
significantly on the strength and impact of this trough. It is
not forecast to bring any precipitation according to the latest
NBM. However, if the stronger members of the ensembles come to
pass, it would bring showers and perhaps thunderstorms across
our northern zones Sunday, along with a breezy day across most
of the region. Monday is expected to be dry and cooler, but how
much cooler will depend on the strength of the system. At this
time, the forecast is for a return to normal Monday after an
week of above-normal temperatures.

&&

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

&&

$$

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DISCUSSION...LC
AVIATION.....JR
SHORT TERM...SP
LONG TERM....SP