518
FXUS65 KPIH 142032
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
132 PM MST Thu Nov 14 2024

.SHORT TERM...Tonight and Friday
Afternoon satellite imagery shows some fair weather CU across the
higher terrain of eastern Idaho as well as some mid/high level
cirrus streaking across the southernmost part of the Gem State.
Aside from that, it`s a rather quiet afternoon with ample sunshine
and seasonal temperatures. Enjoy while you can because things
change drastically overnight and into the day Friday. A potent U/L
trough digging into the PacNW this afternoon will move over our
area during the day tomorrow bringing clouds, much cooler
temperatures and precipitation (mostly snow) to the region. Clouds
will begin to increase during the overnight hours but most of the
precipitation will hold off until around daybreak tomorrow in the
central mountains and by midday Friday, should be impacting just
about everyone across eastern Idaho. Locations above 5500 ft will
see snow throughout the event but lower elevation areas in the
Snake Plain and Magic Valley COULD see a brief period during the
afternoon when we see more of a mix or even all rain but there
will only be a very thin layer of the atmosphere above freezing
during this period and we`ve seen it many times where models can
overdue this and/or other atmospheric conditions occur bringing
that freezing level just above or near the surface. That being
said, precip type is a bit tricky but only for a brief period
before everything will change to snow. The snow will linger into
the day Saturday as well along with much cooler temperatures. See
below for specific snowfall amounts over the Friday - Saturday
time period. McKaughan

.LONG TERM...Saturday through Thursday
Snow will wind down Saturday, with linger light showers across
the eastern and southeast highlands by afternoon. There is some
potential for some pockets of blowing snow during the morning
hours but nothing widespread. Looking at rain/melted snow numbers,
that gives most valley areas anywhere from a few hundredths to
around 0.25". For most mountain ranges, we are looking at up near
0.50". There still appears to be a heavier band from the Big Holes
down through the South Hills and Albion Mountains, including
bench areas from Idaho Falls to Burley. That looks to crank out up
to near 0.50" for the valleys and 0.75- 0.80" in the
mountains...locally higher south of Burley. There is a 10-15%
chance of picking up more than 0.50" from Idaho Falls to Burley
down low, and a 10-20% chance of more than 0.80" for higher
elevations along the benches. That equates to up to 3" of snow for
lower elevations and up to 7" for the mountains...depending on
location. Along the Idaho Falls to Burley corridor, that means
2-5" for the valleys/benches with up around 10" for some highest
elevations. The next even isn`t far behind, and begins in the
central mountains early Sunday, spreading eastward Sunday night
and Monday. Early totals for that one show a few hundredths in the
valleys and up to near 1/3rd of an inch for the mountains. The
Sawtooths and eastern highlands are favored with 0.40-0.60". Snow-
wise, that gives us a Trace to near 2" for most folks and up to
5" in the mountains. For those favored areas, we COULD see up to
8" for higher peaks and ridgelines. Eventually by the end of next
week, strong high pressure is still forecast as a blocking pattern
tries to set up from the Pacific across the lower 48. Highs
struggle to hit 40 over the weekend in some spots, and the
mid/upper 30s next week under the ridge. We will need to watch for
inversion conditions due to the strength of that ridge. Keyes

&&

.AVIATION...
VFR conditions in place this afternoon with mostly clear skies and
light winds. Winds will remain light through the period but CIGs
will gradually lower and the sky will become more obscured with
clouds as our next weather system moves in overnight and into the
day Friday. KSUN will be the first to see precip, likely after
sunrise tomorrow, and eventually overspread to the rest of the
east Idaho terminals between 15-18Z. Snow will be dominant precip
type at KSUN and KDIJ but KBYI, KIDA, KPIH will see a period of
RA, RASN before becoming all snow later in the day Friday. Snow
will likely bring a prolonged period of MVFR to localized IFR
conditions to all terminals. These impacts are all just beyond the
current TAF period however but will be applicable for the 00Z TAF
issuance. McKaughan

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$