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fxus65 kboi 261649 

Area forecast discussion
National Weather Service Boise Idaho
949 am MST sun Feb 26 2017

Discussion...updates not needed for current forecast. Snowfall
noted across the west central mountains of Idaho and reaching into
McCall this morning. Gusty gradient wind impacting portions of the
upper Treasure valley, which may continue for a few hours. Snow
will continue to increase in coverage today, though most areas are
expected to see light accumulation, other than the west central
mountains of Idaho which remain under a Winter Weather Advisory
through Monday morning.


Aviation...generally VFR. Snow showers moving in from the
northwest, progressing southeast. MVFR/IFR conditions in heavier
snow showers. Heaviest showers expected in the west central and
Boise Mountains with lighter accumulations elsewhere, generally
above 4k ft mean sea level before sunset and dropping to valley floors
overnight. Mountain obscuration in snow showers and low ceiling
heights. Surface winds: southeast to southwest 10-20 kts,
diminishing in the afternoon. Winds aloft to 10k feet msl: SW 15-30
kts, turning west 10-20 around 03z.


Previous discussion...
short through Monday...cold upper trough will carve
out a position over the pac northwest through Monday. Energy dropping
into the trough along with afternoon instability will keep a
chance of showers over much the area, though the focus of more
continuous snowfall will be across the east-central Oregon and
central Idaho mountains. Highest accumulations still look to
concentrate over the west-central Idaho mountains with slightly
lesser amounts in Baker County, the Weiser basin and Boise
Mountains. Further to the south, to include the snake plain and
southeast Oregon, precipitation amounts will be light, totaling a
tenth of an inch or less through Monday. Snow accumulation will
generally be limited to sites above 4k feet during the daylight
hours, though temperatures Sunday night will be cold enough to
support accumulations at all elevations. Any snowfall Sunday night
in the lower basins and valleys will be sporadic and light, with
less than an inch for sites that see snow. The advisory for the
west-central Idaho mountains remains in place, while rest of area
stays below criteria. Winds pick up today ahead of the trough,
adding a windchill to the well below normal temperatures. Winds
are lighter tonight and Monday, but temperatures will remain
around 10 degrees below normal.

Long term...Monday night through Saturday...models still have the
cold upper level trough exiting east of our area on Tuesday,
followed by cool northwest flow aloft through Thursday. There will
be enough moisture embedded in this flow for snow showers over the
mountains of Baker County Oregon and central Idaho, but the
remainder of our area is expected to be dry. Friday through Saturday
a Pacific weather system will spread precipitation across our area.
There will be a gradual warming trend through the period, and
temperatures will be close to normal Friday and Saturday, with snow
levels rising to around 5000 feet.


Boi watches/warnings/advisories...
Idaho...Winter Weather Advisory until 11 am MST Monday idz011.




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