Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service Boise Idaho
905 PM MST sun Feb 26 2017
Discussion...a strong upper low is located in western Oregon this
evening, and it's moving southeast. I will swing eastward through
our area as it becomes an open wave tomorrow. This is helping to
initiate areas of snow showers, some of which have been rather
vigorous. Up to an inch of snow has fallen with the stronger
showers in the lower elevations of southeast Oregon and southwest
Idaho this evening. However, much of that melted off rather
quickly, especially on the roads. More snow has fallen in the
mountains, with McCall reporting around 3 inches so far today. The
snow stake at Brundage has reported around 8 and bogus has seen
around 3. Another inch or so is expected in McCall tonight, with
higher amounts in the mountains. Lower elevations will only see a
trace to perhaps half an inch.
An area of concern in the southwest Highlands east into southern
Twin Falls County. Latest guidance gives them anywhere from 1 to 3
inches overnight. Confidence in seeing the higher number
materialize is low at this time because of the showery nature of
the precipitation, so will not change the forecast. However, felt
is was Worth mentioning that some of guidance is indicating an
event that would be worthy of an advisory.
Aviation...mostly VFR. Snow showers will continue through Monday
evening. MVFR/IFR conditions within heavier showers and higher
elevations. Surface winds, southerly 10-15 kts. Winds aloft to 10k
feet msl, westerly 10-35 kts.
short term...tonight through Tuesday...light snowfall continues
across the northern forecast zones this afternoon, with accumulation
noted on webcams across the impacted areas. Snowfall is not meeting
its potential based on past forecasts, but will wait to adjust any
highlights in case additional intensity begins. The alaskan trough
producing the surrounding snowfall has weakened a bit since coming
on shore, but may still bring low advisory amounts across the
northern zones. Light accumulations expected elsewhere over Baker
County and the Boise Mountains. Hi-res models indicate the potential
for a few bands of snowfall to impact the Treasure valley this
afternoon and evening, but do not appear likely to produce much in
the way of snowfall accumulation. Wind associated with the leading
edge of the trough will weaken as the trough progresses eastward
through the afternoon evening hours. Snowfall across the area is
expected to weaken through Tuesday, though a dirty northwest flow
over the area will keep some shower activity present through Tuesday.
Long term...Tuesday night through Sunday...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.
Idaho...Winter Weather Advisory until 11 am MST Monday idz011.