Area Forecast Discussion
Issued by NWS Boise, ID

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FXUS65 KBOI 202209

Area Forecast Discussion
National Weather Service Boise ID
309 PM MST Fri Jan 20 2017

.SHORT TERM...Tonight through Sunday...Snow continues in much of
southeast Oregon this afternoon. Burns has received 1 to 2 inches
as of 130 pm PST, and this is likely representative of northern
Harney county. Snow will continue and spread northeast this
evening. Amounts will taper off after midnight, and the advisories
will be left in place. Looking at the bigger picture, a negatively
tilted upper level short wave trough will rotate over the area
tonight, leaving zonal flow briefly in its wake tomorrow. Saturday
night, as another short wave trough moves closer, upper flow will
turn back to southwest. Finally, on Sunday, one piece of this
upper level trough will move through the area. The result of this
rapidly evolving flow will be our current snow lasting toward
midnight, followed by scattered snow showers Saturday (mixing with
rain at lower elevations), followed by a relatively dry Saturday
night, to be finished off with another snow on Sunday. Sunday`s
snow amounts will be similar to the system today. We may end up
issuing an advisory for that storm as well, but will let today`s
system finish up before moving on to the next one. Temperatures
will be more mild than what we have become accustomed to this
winter, with readings at or slightly above normal through Sunday.
This could easily result in mixing of rain with snow at elevations
below around 3000 feet.

.LONG TERM...Sunday night through Friday...Warm front will push
across southwest Idaho and southeast Oregon on Sunday night, and
snow levels will rise to around 3500ft in the Boise area, snow
levels will stay lower in the Magic and the lower Treasure Valley
and Weiser River Basin towards Baker County. A cold front moves
through the region on Monday morning, and snow levels fall to the
valley floors at all locations. Snow amounts of 2-4" possible in
the lower Treasure Valley and Malheur county and 3-6" across the
mountains as this feature moves across the area. A ridge begins to
build across the West Coast on Wednesday, allowing cold northerly
flow to develop. Temperatures expected to be below normal through
the remainder of the extended period with inversion conditions


.AVIATION...Generally VFR in southwest Idaho with conditions
deteriorating. Snow across SE Oregon spreading into SW Idaho later
this afternoon with widespread MVFR-IFR conditions as the snow
passes through. Expect a rain/snow mix in Upper Treasure Valley
near KBOI, KEUL. Mountains becoming obscured. Winds aloft at 10kft
MSL: southerly 20-30kt becoming WSW 10-20kt by 09z/Sat. Surface
winds: generally E-SE 10-20kt, strongest in Baker and upper
Treasure Valley.

Weekend Outlook...Mountains will be obscured. Scattered to isolated
snow showers will remain over the area Saturday and Saturday night
with MVFR conditions and areas of IFR conditions. Next round of snow
will move over the area Sunday into Monday for widespread MVFR and
areas of IFR conditions.


OR...Winter Weather Advisory until 11 PM MST /10 PM PST/ this evening



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