Area Forecast Discussion
Issued by NWS Pocatello, ID
FXUS65 KPIH 081621
Area Forecast Discussion
National Weather Service Pocatello ID
921 AM MST Thu Dec 8 2016
.UPDATE...Progression of precipitation into East Idaho on target.
Have made only minor update today to split weather grids to better
depict spread of precip across region this afternoon and evening.
Have made no changes to QPF or snow grids. Heaviest snowfall to
target Snake Plain 21Z-06Z with snow continuing across higher
elevations overnight. Headlines in great shape, no other updates
planned at this time. DMH
.PREV DISCUSSION... /issued 340 AM MST Thu Dec 8 2016/
SHORT TERM...Today through Saturday.
Active short term period with a variety of winter storm warnings
and advisories in effect from this afternoon through Saturday.
First round of precipitation will come this afternoon through
tonight as Pacific moisture begins to overrun the very cold air
currently in place over southeastern Idaho. Have winter storm
warnings in effect for all mountain zones and a winter weather
advisory for the Snake River Plain and Franklin County. Ended the
advisory late Friday morning in the Snake Plain as warmer air
should change any precipiation left to rain by Friday afternoon
and evening. Kept the warnings in place for the mountains through
Saturday as after a slight break in precipiation Friday morning
heavier precipiation will move back in Friday afternoon and
evening. Temperatures will remain very cold and below normal today
then remain steady overnight or even rise and then rise to above
normal by Friday. Expect snow levels to rise to above 5 thousand
feet Friday afternoon then drop back down to valley floors
LONG TERM...Saturday night through next Thursday. Models continue
to show our area remaining in a moist West Northwest flow Saturday
night through early Tuesday. Expect mainly mountain showers. Though
with heavier periods of moisture, snow will likely extend into the
valleys. Will have to wait for future model runs to pin down timing
of periods of heavier snow. Tuesday afternoon a trough drops down
from the North leaving us in dry...very cold...North Northwest flow.
Expect much cooler temperatures Tuesday afternoon through Wednesday.
Late Wednesday into Thursday expect a moist West Southwest flow
bringing back a good chance of snow. Though there is a lot of
uncertainty, models are indicating a chance of rain and/or a rain
snow mix across lower elevations for the Eastern Magic valley, Snake
River plain and the Southern Highlands. Wyatt
AVIATION...Expect fog at KPIH and to an lesser extent at KIDA
through mid morning. Otherwise, look for VFR conditions until this
afternoon when the next system arrives. KSUN and KBYI will be the
first TAF sites to go down to MVFR/IFR conditions with snow around
mid afternoon. KPIH and KIDA will drop down to MVFR/IFR conditions by
late afternoon with KDIJ dropping down by early evening. Expect all
TAF sites to remain in MVFR/IFR conditions through Thursday evening
and most of Friday. Wyatt
Winter Weather Advisory from 1 PM this afternoon to 11 AM MST
Friday for IDZ017-020-021.
Winter Storm Warning until 5 PM MST Saturday for IDZ018-019-022-
Winter Weather Advisory from 1 PM this afternoon to 5 PM MST
Saturday for IDZ024.