FXUS65 KBOI 091025
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
325 AM MST Fri Feb 9 2024

.SHORT TERM...Today through Sunday night...A short wave trough
currently over Washington will bring snow showers to our Oregon
zones this morning and Idaho zones mid-morning through early
afternoon, ending from north to south along the ID/NV border
this evening.  Snow amounts will be minimal, ranging from a
dusting to a half inch in most areas, up to several inches in
Owyhee County. The Treasure Valley has less than 30 percent
chance of receiving as much as 1/2 inch, with most of the snow
falling between 6 AM and noon. This timing may slightly impact
the morning commute in the Boise metro with a few slippery roads
after 7 AM and reduced visibility in falling snow. Light to
moderate northwest winds today, with gusts to 20 mph in the
Snake Basin east of Boise this afternoon. The short wave
trough will continue to move south tonight into the existing
larger scale upper trough over the Great Basin. Colder and
drier northerly flow aloft late tonight through Saturday will
bring mostly clear skies, except patchy valley fog, and more
winter- like temperatures to our CWA. An upper ridge will come
in from the Pacific with milder temperatures at higher
elevations beginning Sunday and in the valleys beginning Monday.
A weak upper trough from the north Pacific will increase clouds
Sunday night, with flurries in northern areas.

.LONG TERM...Monday through Friday...A shortwave trough from
the Gulf of Alaska will move into the Pacific Northwest on
Monday. Models differ on how far south this will reach, but the
system is not expected to contain much moisture. This results in
a 20-40% chance of snow over the northern mountains, with less
than a 15% chance of precipitation elsewhere. On Tuesday and
Wednesday, another trough is expected to move south from Canada,
but its progress may be impeded by an upper level ridge along
the West Coast extending into the Desert Southwest. Models also
differ on whether a trough from the eastern Pacific will move
through the ridge and bring increased moisture into our area
during this time. Chances of precipitation will remain similar
to Monday as these systems approach our area. Uncertainty
increases further Thursday and Friday with the evolution of the
ridge and additional systems arriving from the west. A more
amplified pattern would shift moisture to our north, while a
weaker ridge would allow more moisture to move into our area.
Precipitation chances increase Thursday and Friday, but still
remain relatively low (15-30%) due low confidence in the
pattern. Temperatures are forecast to gradually increase through
the period, starting from near normal on Monday and ending
around 5 degrees above normal by Friday.

&&

.AVIATION...Widespread light snow arriving from NW this morning,
creating MVFR/IFR and local LIFR conditions through this afternoon.
Snow showers decreasing in the valleys this afternoon but
continuing in the mountains. Mountains obscured in precipitation
and low clouds. Surface winds: W-NW 5-15 kt. Winds aloft at
10kft MSL: NW 10- 20 kt, becoming N 10-15 kt after 00Z/Sat.

Weekend Outlook...Areas of fog/low stratus Saturday morning.
Otherwise, conditions improving to VFR the remainder of the
weekend under drier NW flow aloft. Increasing mid to high
clouds later Sunday. Surface winds generally W to NW 5-10 kt
Sat, shifting to SE to SW 5-15 kt Sunday.


&&

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

&&

$$

www.weather.gov/Boise
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise

SHORT TERM...LC
LONG TERM....ST
AVIATION.....ST