000 
FXUS65 KBOI 112021
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
221 PM MDT Sat Sep 11 2021

.SHORT TERM...Tonight through Monday night...Valley fog this
morning was more extensive than forecast and helped delay 
daytime warming, but afternoon sunshine will allow temps to 
reach forecast highs. Residual moisture weakly connected to 
the tropical storm near Baja California will develop isolated 
thunderstorms in southern Twin Falls County early this evening. 
Elsewhere tonight skies will be clear in the south and mostly 
clear in the north. Patchy fog will again form in the valleys 
early Sunday morning but less extensive than today. Sunday will
be mostly sunny in the south and partly cloudy in the north, 
and several degrees warmer than today as the next weak Pacific 
trough comes inland. This trough will bring a slight chance of 
thunderstorms to southern Twin Falls County late Sunday afternoon 
and evening. Sunday night should be warmer than tonight under 
partly cloudy skies. Monday will be sunny and cooler as the weak 
upper trough passes through. Some afternoon clouds will develop
in the central Idaho mountains. Monday night looks clear and 
cool. West-southwesterly flow aloft will continue to bring smoke 
into central and southern areas Sunday, but Monday looks clearer 
in northern areas as flow aloft turns to northwesterly.

.LONG TERM...Tuesday through Saturday...A large upper level low 
pressure system will remain over northwestern Canada with west to
northwest flow over the region. This will keep temperatures at or
slightly below normal Tuesday and Wednesday, with shortwaves 
passing by to the north, but no precipitation. A dry cold front 
will bring cooler temperatures on Thursday and Friday. Ensembles 
favor a longwave trough developing over the Pacific Northwest on 
Saturday which would bring cooler temperatures and showery 
conditions.

&&

.AVIATION...VFR. Mostly clear skies through Sunday. Surface winds: 
W-NW 5-10kt during the afternoon, becoming variable 10kt or less 
after sunset. Winds aloft at 10kft MSL: W-NW 15-25kt easing to 5-
15kt by 00z/Sun.

&&

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

&&

$$

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SHORT TERM...LC
LONG TERM....JDS
AVIATION.....JDS