114
FXUS65 KRIW 191045
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
345 AM MST Wed Nov 19 2025

.KEY MESSAGES...

- Near to slightly above seasonable temperatures remain across
  the Cowboy State today.

- A weak disturbance may bring periodic isolated showers over portions
  of western and southern WY throughout the day today into
  Thursday.

- Quiet and dry weather with near seasonable temperatures are expected
  to persist into the weekend.

- Chances for colder temperatures and precipitation may return
  to the region for the second half of next week.

&&

.DISCUSSION...
Issued at 137 AM MST Wed Nov 19 2025

Near seasonable temperatures and mainly uneventful weather will
start today and likely persist into the weekend. Temperatures remain
at or slightly above normal today with highs in the low to mid 40s
west of the Divide and low to mid 50s east of the Divide. Much of
the state looks to see quiet conditions with partly to mostly cloudy
skies. The exception to this will across portions of western and
southern WY. A weak shortwave will interact with moisture that is
being funneled into the region by a cutoff low from the southwestern
CONUS. This will lead to periodic showers throughout the day today.
The best chances (20-50%) for showers is expected to be across
western WY with lesser chances (10-30%) for parts of southern WY.
Showers gradually dissipate with coverage lessening by the morning
hours on Thursday. The highest elevation mountain ranges of western
WY may see a light coating or at most an inch or two of fresh
snowfall by this time.

The second half of the week into the weekend will see temperatures
remain near to slightly above seasonable with mostly quiet and dry
weather prevailing. This is due to two upper level lows managing
to navigate their way around the area, which seems to be the
theme of November so far. The cutoff low mentioned earlier
currently is over the southwestern CONUS and will gradually
shift east through the second half of the week. This shift looks
to quicken due to another low digging south from the PACNW and
replacing the first low leading to it stagnating over the same
area by Thursday into Friday. The first low is ejected to the
east remaining well to the south of the state to see any
widespread or noteworthy impacts. At most a few showers may be
possible over southern WY (10-30%) late Thursday night into
Friday. The weekend currently looks quiet as the second low
settles in over the southwestern CONUS and zonal flow developing
over the area. The second low will gradually shift east through
the weekend, once again remaining well to the south to see any
impacts here.

Looking ahead to the start of next week, the jet stream is expected
to become active again. This translates to the possibility of
multiple rounds of disturbances moving into and through the region.
However, similar to this week the track and setup will be the key
factors in determining if the state may see any impacts. Along with
the possibility for precipitation there may be a strong push of
cold arctic air for the second half of the week. Models differ
with the track of this cold air with some keeping the coldest
temperatures to the north and east of the area. Overall, many
locations are still awaiting the first real snowfall of the
season, especially east of the Divide. The late arrival of the
first measurable snowfall (1" or more) is starting to near
record values. One location for example is Lander where as of
November 18th is sitting within the top 10 for latest first
measurable snowfalls. If the close calls with disturbances
continues through next week, its very possible Lander may be
within the top 5 latest dates on a record which goes back to
1891. That being said, there may be some chances for
precipitation late next week and with Thanksgiving next Thursday
it bears monitoring.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 345 AM MST Wed Nov 19 2025

Mainly VFR conditions for the entirety of the period outside of
JAC with MVFR ceilings later in the period. Light winds and
scattered to broken mid to upper level clouds throughout. Some
light snow at JAC/BPI/PNA after 00-02Z west to east respectively
ending between 06-07Z. This is a bit later with the previous
trends, and since after sunset and cooler temperatures, expect
this to be in the form of snow at that point in time. Otherwise,
mid level ceilings overnight with JAC seeing a low MVFR stratus
deck off Jenny Lake with the switch to a light northerly flow
after about 06Z and through the end of the period.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for
the latest information on smoke, icing, and turbulence
forecasts.

&&

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

&&

$$

DISCUSSION...Dziewaltowski
AVIATION...Lowe