348 
FXUS65 KBOI 060209
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
809 PM MDT Sat Nov 5 2022

.DISCUSSION...A few light sprinkles of rain and a few snow 
flurries have been observed around the area this evening, but 
mostly dry conditions will prevail overnight. Patchy early morning
fog is possible especially in higher mountain valleys. Westerly 
winds will continue to slacken overnight and then become 
southeasterly on Sunday. The forecast remains on track for rain 
and snow to move back into the area on Sunday night. 

&&

.AVIATION...Generally VFR conditions, with periods of MVFR in 
light/moderate showers over higher terrain through this evening. 
Mountain obscurations. Pockets of mountain valley fog Sunday 
morning. Precipitation will return late Sunday afternoon/evening 
creating periods of MVFR conditions and mountain obscurations. 
Surface winds: W-NW 10-20kt with gusts 25-35kt, decreasing to 
variable 5-15kt after 00z/Sun. Winds aloft at 10kft MSL: NW 40-55kt 
becoming NW 25-40kt by 00z/Sun.

&&

.PREV DISCUSSION...
SHORT TERM...Tonight through Monday night...Surface cold front, 
marked by a line of showers, has moved south to the Snake River 
as of 130 PM MDT. However, clouds still cover our CWA except in 
northern Baker and Valley Counties where clearing has started. 
The cold front also marks the northern edge of the strong winds. 
Winds will therefore decrease in southern-most Idaho by late 
afternoon. Tonight will bring gradual clearing from north to 
south and also cooler temperatures as the supporting upper 
trough expands southward from western Canada and the nearby 
Pacific. The trough will dig southward most strongly along the 
coast Sunday and Sunday night leaving our CWA under strong 
southwesterly flow aloft and an east to west surface pressure 
gradient. The pressure gradient will result in breezy easterly 
winds Sunday. As the upper trough and low move south, rain and 
snow showers will increase in our CWA Sunday night and Monday. 
Late Monday night the upper low will be along the northern 
California coast and showers will decrease in Oregon, but will 
continue in south-central Idaho under moist southwesterly flow 
aloft. Temperatures will be near normal through Monday, then
lower to slightly below normal Monday night.

LONG TERM...Tuesday through Saturday...A large and cold low 
pressure center is anticipated to move southward along the west 
coast on Tuesday, and progress eastward on Wednesday. With unstable 
cold air aloft and associated moisture with the low, a chance of 
rain/snow showers is forecast across southeast Oregon and southwest 
Idaho for these days. Chilly, northwest flow will develop aloft 
later on Wednesday and into Thursday that will support gusty 
northwest winds at the surface, especially Wednesday when the 
pressure gradient will be strongest. Beginning Thursday, models 
are depicting drier conditions as weak high pressure is expected 
to build into the area. However, ensemble model guidance suggests 
great forecast uncertainty after Thursday. Overall, expect 
temperatures to drop around 10-15 degrees below normal by mid-week
to late week.

&&

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

&&

$$

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DISCUSSION...JB
AVIATION.....AL
PREV SHORT TERM...LC
PREV LONG TERM....SH