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fxus65 kboi 202059 

Area forecast discussion
National Weather Service Boise Idaho
259 PM MDT sun Aug 20 2017

Short term...tonight through Tuesday...tonight and Monday will
remain dry with temperatures near normal. The leading edge of a
cirrus shield has pushed into E-central Oregon and W-central Idaho
this afternoon. This area of clouds is accompanying a weak upper-
level trough which will cross southeast Oregon and southwest
Idaho overnight. While afternoon satellite imagery shows an
extensive area of high clouds upstream across WA, dry and stable
air following the trough passage will erode the backside of the
cloud shield early Monday morning. Thus expect clear conditions
across southeast Oregon and southwest Idaho for the eclipse. North
to northwest flow in the low to mid-level will continue to keep
much of the smoke from the large fires in central Oregon west of
the area. However some haze and thin smoke layers aloft will
persist through the period. Mountain valleys north and east of
McCall will be the exception due to smoke from nearby large fires
in N-central Idaho.

For Monday night into Tuesday winds shift to the southwest,
warming temperatures and increasing moisture. By late Tuesday
afternoon a slight chance of showers and thunderstorms will exist
along the Nevada border. Temperatures will warm to 4-7 degrees above

Long term...Tuesday night through upper low off the
coast of British Columbia is expected to draw up a closed low near
coastal California, and bring moisture to the area. As that trough
swings inland on Thursday, a cold front is expected to pass through
the area possibly later on Thursday into Friday morning. A chance
of showers and thunderstorms exists on Wednesday afternoon, into
Thursday, and ending Friday morning. For Friday and beyond, a ridge
builds into the western US, so conditions are expected to dry and
warm through the weekend.


Aviation...VFR with passing high clouds. Smoke layers. Surface
winds: generally west/northwest 10 kts or less. Winds aloft near 10
kft msl: west/northwest 10-15 kts.


Boi watches/warnings/advisories...




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