FXUS65 KBOI 211013
Area Forecast Discussion
National Weather Service Boise ID
313 AM MST Wed Nov 21 2018
.SHORT TERM...Today through Friday...Generally dry conditions
anticipated for much of the day, with models showing increasing
moisture through the evening hours. Reduced mention of activity
during the daytime, but increased the evening with the trough
approaching the area. Precipitation will spread eastward tonight,
moving into Idaho early Thursday morning with activity continuing
through the day. Snow levels will hover around 4000-5000 ft, with
mountain snow and valley rain. The anticipated increase in
activity remains on track for Friday, when potentially significant
mountain snow will be possible through Friday night as low
pressure dives south towards the Washington coastline. This
approach will also increase the pressure gradient on Friday
afternoon, resulting in gusty wind for portions of the forecast
area. Additionally with this diving low pressure, decreased
daytime temperatures several degrees for Friday.
.LONG TERM...Friday night through Wednesday...Drying and colder
over the weekend as Friday's upper trough moves out and the next
Pacific upper ridge moves onshore. The ridge will move inland and
dominate through Tuesday with generally dry weather and also
moderating temperatures mainly at higher elevations. Models
diverge Tuesday and Wednesday but they still agree on moist
westerly flow into our area for a chance of light rain and snow on
.AVIATION...VFR. Increasing clouds from the west after 18Z.
Scattered rain and snow showers after 21z/Wed in SE Oregon and
06Z/Thu in SW Idaho with mountains becoming obscured. Snow
level 3000-4000ft rising to 4500-5000ft Thursday. Surface winds
southeasterly 5-10kt. Winds aloft near 10kft MSL, southwest
FXUS65 KPIH 210905
Area Forecast Discussion
National Weather Service Pocatello ID
205 AM MST Wed Nov 21 2018
.SHORT TERM...Today through Saturday. Timing is still consistent
with approaching upper trough. Precip will spread west to east
starting Thanksgiving morning. Light snowfall is expected for the
Snake Plain through Thursday evening as precip will start as rain.
A second shortwave trough will push through on the heels of the
first, bringing greater precip amounts as moisture transport ramps
up with stronger winds in the mid-levels. Significant mountain
snowfall is expected Thursday night into Friday associated with
the second shortwave. Lower elevations will again see most of this
as rain, but snow levels look to drop to valley floors late
Friday night into Saturday while a third upper trough works into
Idaho from the northwest. Current headlines still representative
of latest forecast. Will keep the winter storm watch rolling given
forecast snow amounts and wind speeds. Hinsberger
.LONG TERM...Saturday night through Wednesday.
Storm system departs the region Saturday night providing mainly dry
weather and near normal temperatures for a couple of days. There
will be some weak disturbances brushing through the region, but we
probably won't see much more than flurries or a dusting of snow.
Next system of any real consequence arrives Tuesday. At this point,
this does not appear to be a major storm but could produce some
light rain/snow to the region for Tuesday and Wednesday.
Expect vfr conditions with light winds at all TAF locations today.
Will begin to see lowering clouds tonight with precipitation
possible by Thursday morning in some locations.
Winter Storm Watch from late Thursday night through late Friday
night for IDZ060-062>064.
Winter Storm Watch from Thursday evening through late Friday
night for IDZ071>074.