265
FXUS65 KPIH 232036
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
136 PM MST Sat Nov 23 2024

.SHORT TERM...Today through Sunday Night.
No major changes to the short term forecast as a cold front works
its way across Eastern Idaho today. Radar this morning showed plenty
of moisture out there, but we had some dry air at the surface to
overcome to get much more than sprinkles. As of this discussion
being posted, our population areas are finally seeing some rain as
the cold front itself comes through the Snake Plain and we are
seeing a better band of precipitation moving through the I-15
corridor at 130 PM MST. With this afternoon`s brief window of
rain, these few hundredths of QPF will be it for organized
activity in the Magic Valley and Snake Plain. A few isolated
showers will linger through the evening, but don`t expect much
from those, so any snowflakes we see once the cooler air arrives
will amount to very little, if anything. You have to head farther
north near Rexburg and Saint Anthony to get anywhere near an inch
of snow, and even that`s only about a 20 to 30 percent chance.
Scattered showers will continue in the Central Mountains until
midnight or shortly after, but will be dry for Sunday. Galena
Lodge snow stake camera shows the 3 inches of snow it has gotten
from 9 PM Friday night to 1030 AM MST today with another 2 to 4
inches expected there and near Stanley through tonight. Given this
timing and additional snowfall, will continue the Winter Storm
Warning & Winter Weather Advisory in the Central Mountains until
11 PM as planned. Moisture remains a bit more organized in the
Southeastern Highlands through tonight where snow totals around
Emigration Pass have at least a 70 percent chance to surpass 4
inches and a 40 to 50 percent chance to surpass 6 inches by Sunday
evening based on the latest HREF data. Up in the Island Park
area, snow totals are forecast to be in the 3 to 5 inch range with
about a 50 percent chance of exceeding 4 inches of snow by Sunday
evening. Again, given this expected snowfall, will continue
Winter Weather Advisory in both locations. Much of the Eastern
Highlands in general will pick up about 1 to 3 inches of snow by
Sunday evening.

In addition to the rain and snow today, it`s breezy out there with
the strongest winds out across the Arco Desert/Mud Lake area with
gusts around 35 to 40 mph, with an isolated gust or two around 45
mph. It`ll remain breezy through the Snake Plain and parts of the
Southeastern Highlands with gusts of 30 to 40 mph at times. The gusty
winds and period of heaviest snowfall in the Bear River Range don`t
quite line up, but remember that any snow falling with gusty winds
will reduce visibility and create difficult travel conditions. Early
Sunday morning, some low stratus/patchy fog will exists up in the
Island Park area and across parts of the Arco Desert and eastern
Magic Valley, but impacts will be minimal and not widespread. Highs
on Sunday will be about 10 degrees cooler with most of us in the 30s
to low 40s. Moore

.LONG TERM...Monday through next Saturday.
Following a brief ridge of high pressure Sunday into Monday morning,
our next Pacific trough remains on track to move onshore early next
week with another round of precipitation chances Monday-Wednesday.
With highs Monday and Tuesday in the mid 30s to mid 40s, we are
expecting a mix of rain and snow below about 5000-5500 feet with all
snow expected above 5500 feet. Isolated to scattered showers will
build in throughout the day Monday into Monday night before becoming
more scattered to widespread Tuesday into Tuesday night as the H5
trough axis moves onshore and into Idaho. As this system departs
east on Wednesday over the Continental Divide, snow showers will
shift southeast as a colder airmass settles in midweek with highs
back in the mid 20s to mid 30s. Snowfall totals Monday-Wednesday
will remain generally light overall with a T-3" in the valleys and
an elevation dependent 1-6" in the mountains, locally higher in the
Bear River Range and across the highest elevations along the Wyoming
border region to around 6-12".

Starting Thursday, a ridge of high pressure will begin to build into
the NRN Rockies which will lead to an extended period of quiet,
cold, and dry conditions in East Idaho to finish out November into
early December. With the ridge axis expected to remain situated to
our west, we will remain in a broad NW flow pattern which will keep
temperatures at or below normal with highs generally in the mid 20s
to upper 30s. Should any moisture is able to work up and over this
ridge feature late next week we could see some isolated mountain
showers but that remains unlikely at this time. MacKay


&&

.AVIATION...18Z TAFS through 18Z Sunday.
Early afternoon satellite imagery shows a cold front tracking west
to east across southeast Idaho with a mix of rain/snow showers and
winds of 10-20 kts with gusts to 20-30 kts. As this more organized
precipitation band shifts southeast of the Snake River Plain this
evening, showers will become increasingly isolated and trend all
snow as drier conditions prevail tonight into Sunday as a ridge of
high pressure builds in from the west. MVFR/IFR CIGS/VIS will be
possible at times through tonight associated with more moderate
precipitation and or areas of low stratus and fog. For Sunday,
increasingly clear skies will continue to build in from the west as
a drier airmass shifts overhead, keeping any isolated snow shower
potential confined to the mountains. MacKay


&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 5 PM MST Sunday for IDZ060-066.

Winter Weather Advisory until 11 PM MST this evening for IDZ069-
071.

Winter Storm Warning until 11 PM MST this evening for IDZ072>074.

&&

$$