Casper, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

061
FXUS65 KRIW 022359
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
459 PM MST Thu Jan 2 2025

.KEY MESSAGES...

- Light snow showers linger across western WY through the
  afternoon while eastern and central locations see seasonable
  and dry conditions prevail.

- Another round of accumulating snow moves into portions of
  northwestern WY late Thursday night into early Friday
  morning.

- A potent Pacific system looks to move through the region this
  weekend possibly bringing the potential for light snow in some
  locations.

&&

.DISCUSSION...
Issued at 1205 PM MST Thu Jan 2 2025

Ski resorts as well as any winter outdoor enthusiasts are loving the
start to 2025 across western WY. Overnight, another fresh dumping of
snow fell over western mountains and valleys. Snow reports this
morning show portions of Jackson Hole and Star Valley with snow
amounts ranging from 5 to 10 inches. The upper Green River Basin saw
some fresh snowfall as well with amounts of 2 to 4 inches.
Preliminary reports from some western mountains are showing amounts
ranging from 12 to 18 inches. The remainder of the day should be
perfect for any winter activities across western WY. The only thing
to monitor will be a few lingering light snow showers hanging around
the area through the evening tonight. Elsewhere across the CWA
conditions remain chilly but seasonable with dry conditions
prevailing. Some gusty winds are expected to develop across portions
of Sweetwater and Lincoln Counties this afternoon, with gusts of 30
to 40 mph possible at times, eventually diminishing overnight.

Another round of snow moves into western WY early Friday morning
ahead of a potent trough thats digging across the PACNW. This quick
burst of snow looks to be more limited to the northwestern corner of
the state. The current forecast is for 4 to 8 inches of snow across
the higher elevations of the Tetons and Gros Ventre Ranges as well
as the higher elevations of YNP. Lower elevations such as Jackson
Hole may see a quick accumulation of 1 to 2 inches by Friday
afternoon. Overall, impacts will be minimal and at this time no
winter highlights are expected to be issues as a result.

The second half of the week into the start of the weekend will see
quiet and mild conditions over central and eastern portions of the
CWA. Models currently show a ridge building in over the region for
Friday and Saturday. This ridge looks to bring a brief warm up in
temperatures to the CWA with highs reaching the upper 30s to mid
40s. This warm up is short lived as cooler but more seasonable
temperatures return for the end of the weekend into the start of
next week. These cooler temperatures are associated with a potent
Pacific trough that will dig across the CONUS over the weekend.
Models still are not in good agreement regarding how this
disturbance will develop and if it will be close enough to bring a
widespread impactful snow event. At this time that outcome is
looking very unlikely, things are starting to point towards a
widespread minimal impact event instead. The majority of models show
a low that is still too unorganized while it is nearby the area to
produce any significant snowfall but may still create some chances
for light snow as it moves through. Models are showing a period of
light snow possible across central and eastern WY starting Saturday
into Sunday. Preliminary snowfall amounts are marginal with low
elevations maybe seeing anywhere from a quick coating to 2 inches.
However, there still is a lot of uncertainty regarding this system
and there should be a better idea of what we can expect over the
next 24 hours.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 459 PM MST Thu Jan 2 2025

West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals

Western sites continue with midlevel blowover clouds remaining
above VFR levels through the evening. Next weather system moves
into the KJAC area late this evening, with cigs and vis quickly
lowering with return of snow. The start of snow is currently
expected in the 04Z to 06Z period, with lowest cigs and vis
around 11Z Friday morning. The lowest levels of the atmosphere
will warm as warmer air pushes into the region overnight,
making freezing rain a concern and possibility (60% chance) for
a few hours around sunrise. The warm layer that would melt snow
currently looks to be shallow, perhaps 1000 ft in depth, so it
may end up being more "melting snow that refreezes on contact
with ground and other surfaces", but worth a mention here.

This system move through pretty quickly, with much improved
aviation weather after 18Z through the rest of the day.

East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals

VFR conditions expected at all sites through the next 24 hours.
Skies generally clear this evening will be covered by high
cirrus overnight for most areas. Skies will vary between sct and
bkn through the rest of the day, with minimal to no aviation
impacts expected.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Dziewaltowski
AVIATION...VandenBoogart/Straub