Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Boise Idaho
306 PM MDT Sat Oct 25 2014
Short term...tonight through Monday...a large and strong upper
level low is moving into the Pacific northwest this afternoon...and will
progress eastward through the region in the short term. This will
push a cold front through overnight in southeast Oregon...and by noon in
SW Idaho. Showers will move in ahead of the system this evening...
especially in the higher elevations....with a period of showers in
lower elevations mainly tied to the frontal passage late tonight
and tomorrow morning. A Wind Advisory continues until 6 PM MDT...
5 PM PDT...for Malheur and Harney counties in southeast Oregon. Winds
have already gusted to 50 miles per hour at the automated observing site near
Rome Oregon. Much cooler air will move into the region following
the cold front...with highs Sunday 10 to 25 degrees lower than
highs today. The largest change will be in and near the western
Magic Valley where sunshine and southerly winds have brought temperatures
well into the 70s as of 2 PM MDT. Sunday night the precipitation will be
confined to the west central and Boise Mountains as the system moves
east and out of the area. Monday...the only remaining mention of
precipitation will be a slight chance in the west central mountains
temperatures Monday will be similar to Sunday...except in southern Harney
County where a new warm up will begin.
Long term...Monday night through Saturday...a warming trend is
expected to end on Friday as much cooler air from the Gulf of Alaska
enters the intermountain region for the weekend. This is supported
by above-average model agreement...a relatively high measure of
predictability...and a run to run trend toward lower 500mb heights
on Saturday. Near normal temperatures on Tuesday...and scattered
showers Tuesday through Wednesday...will be followed by
temperatures rising to around 10 degrees above normal for Thursday
and Friday. An amplifying upper level ridge will center over our
area by Wednesday night before shifting east of The Rockies on
Friday...leaving southeast Oregon and southwest Idaho under a
southwest flow 0f warm air aloft. At the same time a cold upper
level trough will be deepening offshore...preparing to swing
inland over the interior northwest and Great Basin on Saturday.
This system will lower maximum temperatures by around 15 degrees and
bring scattered showers mainly over the mountains.
Aviation...across southeast Oregon strong southeast to southwest
surface winds 25-35 kts locally gusting to 50 kts will decrease to
10-20 kts after 00z. Elsewhere east to south winds 10-20 kts will
become light and variable after 00z. Expect scattered showers with
mainly VFR conditions tonight except over the central Idaho
mountains where widespread showers by 06z will obscure terrain with
MVFR conditions in the valleys including kmyl. Snow levels will
lower to around 5k feet mean sea level by 12z Sunday. Elsewhere conditions will
slowly improve from the west after 12z.
Or...Wind Advisory until 8 PM MDT /7 PM PDT/ this evening orz061-063.
Short term...snow pellets