Area Forecast Discussion
Issued by NWS Pocatello, ID

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FXUS65 KPIH 092028

Area Forecast Discussion
National Weather Service Pocatello ID
128 PM MST Fri Dec 9 2016

.SHORT TERM...Tonight through Monday. An active westerly flow
pattern with several embedded Pacific disturbances were noted on
satellite imagery early this afternoon. The first in the series of
disturbances was pushing into WRN Oregon with a flat warm-frontal
precipitation signature evident on satellite and region radar
imagery advancing slowly ENE across SRN Idaho. The models continue
to support the idea of warm air associated with the front advancing
into the ERN Magic Valley around noon today and then up through a
portion of the Snake River Plain this afternoon and
evening...[pause]...we are just now seeing that develop in the Twin
Falls area. With that delay in mind we will extend the winter
weather advisory across the ERN Magic Valley and Lower Snake River
Plain zones through 8pm this evening primarily to cover the
potential for freezing rain. The warnings in the mountains are
verifying nicely and will continue through Saturday when the
aforementioned disturbance passes east of the region and the threat
of at least heavy snowfall subsides. Ongoing snowfall is expected
Sunday into Monday as the moist WNW flow continues across the
region. The NW facing aspects of the Sawtooth and Targhee Ranges
should continue to see ongoing light accumulations through that time
frame with intermittent showers intruding into the Snake River
Plain. Again, the models continue to push the idea of warmer temps
into Saturday with moderating daytime highs Sunday and Monday in the
wake of the passing system. We have strayed little from that
guidance. Huston

.LONG TERM...Monday night through next Friday. GFS/ECMWF have
notable differences heading into the long-term periods. ECMWF has
bumped up the timing of the warm front by about 24 hours, with
impacts beginning Tuesday afternoon rather than Wednesday afternoon.
GFS is showing better run-to-run consistency in keeping generally
drier and cooler conditions for the forecast area. Precip chances
are highest over the South Central and Southeastern Highlands
through Wednesday morning, but will keep slight chance to chance
mention elsewhere. Hinsberger

.AVIATION...We continue to see warm air overrunning cooler air in
the valleys so FZRA potential continues for BYI and PIH through
around mid-afternoon. Forecast soundings showing a transition to
rain for those sites with continued warm air advection. Temperature
profiles support continued snow at KIDA...KSUN and KDIJ.
Ceilings/visibility could fluctuate through the bands of heavier
precip expected through the period.  Hinsberger

Winter Weather Advisory continues until 8 PM MST Today for IDZ017-

Winter Storm Warning continues until 5 PM MST Saturday for IDZ018-

Winter Weather Advisory continues until 5 PM MST Saturday for IDZ024.

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