Area Forecast Discussion
Issued by NWS Boise, ID

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FXUS65 KBOI 271616

Area Forecast Discussion
National Weather Service Boise ID
916 AM MST Mon Feb 27 2017

.DISCUSSION...Area of light snow in the western Magic Valley
fading as of 9 AM MST.  Flurries or light snow showers also
in Idaho mountains this morning.  At 9 AM MST satellite showed
weak vort center just north of Valley County, ID, moving east.
Current winter wx advisory for snow in the west Central Idaho
mountains will expire on schedule at 11 am MST.  Next short
wave trough and more light snow again this evening in southeast
Oregon, and mainly from midnight through Tuesday morning in
southwestern Idaho, already in forecasts.  Little change in
temps through Tuesday.  West winds will increase to 15-25 mph
in the Snake Basin Tuesday afternoon.  No updates for now.


.AVIATION...Generally VFR. Snow showers currently over the
Western Magic Valley and south toward the Nevada border will
slowly taper off by early afternoon. Otherwise, snow showers
will be focused over the mountains today. Snow showers will
pick up again overnight for at least a trace over most of the
region with higher amounts over the mountains. MVFR/IFR
conditions within heavier showers with areas of mountain
obscuration. Surface winds: variable 10 kts or less, except
10-15 kts with gusts to 25 kts south and east of KMUO. Winds
aloft to 10k feet MSL: W 15-25 kts, becoming WNW 20-30 kts
after 03Z.


SHORT TERM...Today through Tuesday...Long wave trough over the
Pac NW will keep unsettled conditions across southeast Oregon and
southwest Idaho through Tuesday. An upper wave over s-central
Oregon this morning will track into s-central Idaho by afternoon.
Shower activity will focus out ahead of this system, which
represents the best chance for snow in lower valleys for today.
Mountains will pick up another 1-2 inches this morning while
valley sites see less than an inch. Showers retreat to the
mountains this afternoon in the wake of the upper wave. A second
wave drops into the Intermountain NW tonight with another round of
light snow across all elevations. Amounts will be similar to what
is expected today. Tuesday brings a tightening northwest flow and
the continuation of snow showers across southwest Idaho as drier
air works into southeast Oregon. The northwest flow aloft will act
to ramp up surface winds during the afternoon, especially across
the Snake Plain. Temperatures remain about 10 degrees below normal
through Tuesday.

LONG TERM...Tuesday night through Sunday...Westerly flow aloft will
continue to bring moisture inland across the Pacific Northwest
states. Precipitation will be mainly over northern areas, including
Baker County Oregon and the central Idaho mountains, through
Thursday night. Showers are expected to spread as far south as
northern Nevada Friday through the weekend as a weak upper level
trough crosses the area, with snow levels near 5000 feet.
Temperatures will gradually warm to near normal by Friday.  Models
are in good agreement, and run to run consistency is above average.


ID...Winter Weather Advisory until 11 AM MST this morning IDZ011.



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