Lander, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

749
FXUS65 KRIW 172357
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
457 PM MST Tue Dec 17 2024

.KEY MESSAGES...

- Light snow showers linger across western Wyoming mountains,
  gradually coming to an end by Wednesday afternoon.

- Strong and gusty winds for the Absaroka Mountains, Cody
  Foothills, and western Bighorn Basin Wednesday afternoon
  through early Thursday morning.

- Near record warmth for the end of the week into the weekend
  with highs 10 to 20 degrees above normal.

&&

.DISCUSSION...
Issued at 138 PM MST Tue Dec 17 2024

Those in Star Valley and Jackson Hole woke up to a winter wonderland
with a fresh layer of snow on the ground. Snowfall reports this
morning show amounts ranging from 5 to 9 inches with a few isolated
reports of 10 or more inches. As for those east of the Divide, the
wonderful dry and brown ground is what continues to great us each
morning. Western WY will see light snow showers linger across the
area through Wednesday morning with minimal additional accumulation
expected. The system along with any lingering snow showers clear out
by Wednesday afternoon.

Wednesday has been looking breezy across parts of the state but
recently models have trended towards the possibility of strong gusty
winds. This is due to a shortwave moving across the northeastern
portion of the state. The jet associated with this shortwave is
looking quite robust with 700 MB winds of 60 to 70 knots moving
across northern parts of the CWA. This is creating the potential for
some strong downsloping winds developing across areas east of the
Absarokas. Specifically along the Cody Foothills, along WY-120, WY-
296, US-212, and other locations in the far eastern portions of Park
County. Probabilistic models are showing locations such as Cody and
Clark having a 40-60% of seeing wind gusts of at least 55 mph
Wednesday afternoon/evening. Other locations such as northern
Johnson County, the upper Wind River Basin, and along the Wind
Corridor may see wind gusts exceeding 40 mph at times Wednesday
evening into early Thursday morning. At this time High Wind Watches
are being issued for the Cody Foothills and the Absaroka Mountains
starting mid day Wednesday through late Thursday morning. The main
concern will be strong wind gusts of 55 or more mph in locations
such as Clark and Cody. The concern with the Absaroka Mountains will
be wind gusts exceeding 70 mph especially along the WY-296 over
Chief Joseph Pass.

Winds diminish gradually during the day Thursday as a ridge moves
over the region. Temperatures are forecast to warm up as a result of
this ridge with well above normal highs expected for the second half
of the week. Models are forecasting highs starting Friday to be in
the upper 40s and low 50s east of the Divide which is nearly 15 to
20 degrees above normal. West of the Divide will see above normal
temperatures as well with highs in the mid to upper 30s. Depending
on how warm it gets some locations may near record values with
current record highs sitting in the mid 50s for places like Casper
and Lander. Looking ahead towards the holiday week, there is some
signs pointing towards unsettled weather developing. However, at
this time uncertainty remains high and it will be something to
monitor as we head into the second half of the week.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 455 PM MST Tue Dec 17 2024

Snow has ended and conditions have improved for most valleys
west of the Continental Divide. Scattered mid-level clouds
linger, especially over the mountains with isolated snow showers
and terrain obscurations through Wednesday afternoon. VFR
conditions prevail for basins and valleys overnight into
Wednesday.

Winds will be a major aviation impact Wednesday, especially
during the afternoon and evening. A strong jet stream over
northern Wyoming is in an ideal position to cause a mountain
wave along the Absaroka Range, with extremely gusty winds
impacting the western Bighorn Basin, including KCOD. Wind aloft
a thousand or so feet off the ground will be even stronger. Have
added wind shear mention at KCOD for much of the day, and may
have to consider adding to KLND as well, especially for
Wednesday evening. High Wind Watches are in effect for the
region, indicting the threat of 50 kt gusts at the surface. KCPR
will also be breezy during the afternoon, but winds in central
Wyoming are not expected to be quite as strong as in northern
Wyoming. Winds remain elevated after the TAF period, and into
overnight hours on Wednesday.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from Wednesday morning through late Wednesday
night for WYZ002-003.

Winter Weather Advisory until 5 PM MST this afternoon for
WYZ023.

Winter Storm Warning until 5 PM MST this afternoon for WYZ024.

&&

$$

DISCUSSION...Dziewaltowski
AVIATION...VandenBoogart/Rowe