Local Forecast Discussion

000
FXUS65 KPIH 151004
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
304 AM MST Fri Dec 15 2017

.SHORT TERM...Through Sunday. Widespread Fog continues this
morning, especially across the Interstate corridor. Fog is much
less dense when compared to last night. Considered canceling the
Advisory early, but models suggest Fog should further thicken
towards sunrise. Thus, will continue the Advisory and will
continue to monitor trends.

Attention then turns to the next trough of Low Pressure slated to
wash ashore across the PacNW this evening. This trough will begin
to spread Snow Showers across the Sawtooth/Stanley/Galena Summit
and Willow Creek Summit areas not long after Sunset. Snow is then
expected to develop closer to Midnight across the Continental
Divide/Island Park area and then across the Palisades/Pine Creek
Pass/WY border region towards Sunrise Saturday morning. Shortly
after Sunrise, the trough axis enters the Snake Plain and winds
turn Northwesterly in its wake. These winds will meet the ever
increasing West/West Southwest winds across the I-84/86 Corridor
to set up a Convergence Snow Band, which is expected to develop in
the 8/9 AM hour from Mud Lake to Idaho Falls, then sludge
Southward to Pocatello by late morning, then across the
Coldwater/Raft River and adjacent high terrain to the South
(Sweetzer Summit) by mid-afternoon. Will issue a Winter Weather
Advisory for the Snake Plain/I-15 corridor, Wyoming Border Region
and Montana Border region as a result of anticipated impacts to
travel. Combination of Snow and wind could make for tricky travel
along the I-84 corridor from Burley to Utah border on Saturday as
well, with West winds gusting to 45 mph possible by Saturday
morning for Yale and Idahome. Will hold off on an Advisory for
these areas for now due to less certainty in terms of Snow
Amounts here. Elsewhere, 1-2" across the I-15 corridor from
Pocatello to Idaho Falls and 3-6" for the Continental Divide and
Wyoming border region should be attainable. Snow quickly
diminishes Saturday evening. Fog/Stratus should return across the
Snake Plain for Sunday. AD/Valle


.LONG TERM...Sunday Night through Friday. Models seem to be in
better agreement today with run to run consistency as well. Looks
like moist northwest flow will set up across the region beginning
Sunday night and persist into Tuesday before it lifts northward.
This will bring some light snow showers to the region, but amounts
look very light, generally a dusting to a couple of inches in the
high country. On Wednesday, a cold front will sweep through the
region and this will bring widespread snow to the area. Could see 1
to 3 inches from this storm with higher amounts possible in the high
country. Some lingering snow showers will persist Wednesday night
into Thursday with dry weather likely for Friday.

Valle


&&

.AVIATION...Widespread fog and stratus persists across the Magic
Valley, Teton Valley and Snake Plain. This stratus will produce IFR
conditions today. Will likely see the stratus bust up tonight as a
storm system will arrive late tonight.

Valle


&&

.AIR QUALITY...Poor air quality continues for Franklin county
because of temperature inversions. A storm system will arrive late
tonight, which may help improve air quality for Saturday.

Valle


&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 5 AM to 5 PM MST Saturday for
IDZ020-021-023-025.

Dense Fog Advisory until noon MST today for IDZ017-019>021-023.

Winter Weather Advisory from 11 PM this evening to 5 PM MST
Saturday for IDZ019.

&&

$$

NWS PIH Office Area Forecast Discussion