Area Forecast Discussion
Issued by NWS Pocatello, ID

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FXUS65 KPIH 120959

Area Forecast Discussion
National Weather Service Pocatello ID
259 AM MST Mon Feb 12 2018

.SHORT TERM...Today through Tuesday Night. The closed low this
morning is currently centered along the Oregon/Idaho border near
Boise and Ontario. That is pushing some moisture into Idaho today
as it continues to trek south toward the Sierras. The deeper
moisture is already east of us and drier air is already working in
from the north and west across northern Idaho. This trend is
similar to previous forecast in pushing any potential for through
the day southward. By late afternoon, any real risk of lingering
snow will be south of a Driggs-Pocatello-Burley line. Snowfall
today overall should NOT be widespread, and more dependent on
smaller bands or pockets of showers. We`re already seeing evidence
of that this morning, along with some pockets of drier air in
lower valleys...which may also prevent snow from getting going.
That said, we will be watching the area from Ketchum south
through the South Hills/Albion Mountains as there is a risk (not
huge at the moment) of enhanced snowfall. This is due to
convergence floating around in the general area, but it has been
shifting around a bit. When we say enhanced, we are talking a
little better chance of seeing snow accumulating to over an inch.
This COULD be especially true from the Lava Beds south. Otherwise
snowfall amounts through this evening will be less than an inch.
We also could see locally higher amounts across the Bear River
Range. Gusty winds (mainly out of the north across the Snake
Plain)will slowly die down through the day. While it`s possible
where it is breezy and it tries to snow, some blowing snow might
occur. However, it will be a low threat.

Otherwise, dry conditions return tonight and Tuesday with some
increase in clouds late in the day from northwest. Temperatures
Tuesday morning will be pretty cold in places, with single digits
and teens across the Snake Plain. The central mountains and
eastern highlands will also be cold with typical colder spots
dropping to near/just below zero. We might have to watch for
stratus or fog Tuesday night across the far Upper Snake Plain and
Highlands. Keyes

.LONG TERM...Wednesday through Monday. Long term period looks to
be a continued phasing into a more winter like pattern with
temperatures transitioning to near normal and even below normal
for a good chunk of the period through President`s Day weekend.
The first upper level wave and associated cold front work through
eastern Idaho Wednesday afternoon through Wednesday night. Snow is
likely in the mountains with a chance of snow in the Snake River
Plain. Right now forecasting 1 to 4 inches in the mountains with
under an inch in the Snake River Plain with this first system.
Expect dry conditions Friday with only a slight chance of snow
showers in the mountains. Will see a short warming trend through
Saturday. A second stronger system will likely spread mountain
snow and valley rain and snow into eastern Idaho Saturday with the
chance for snow showers across the entirety of eastern Idaho
Sunday into Monday. Saturday should be the warmest day of the long
term ahead of the cold front with high temperatures expected to
possibly drop to below normal Sunday and Monday behind the front.


.AVIATION...Upper level trof moving over Idaho today should bring periods of
light snow to TAF sites and MVFR ceilings and occasional visibility
restrictions.  Overnight only SUN has dropped to MVFR and IFR
conditions.  Low confidence in timing the restrictions as where the
main snow band develops will determine which sites have the worst
conditions.  Right now think BYI will have the longest lasting below
VFR ceilings and visibilities today.  All sites should be VFR by
20Z.  Widespread VFR expected tonight through Tuesday.



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