Riverton, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

223
FXUS65 KRIW 131952
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1252 PM MST Tue Jan 13 2026

.KEY MESSAGES...

- Record warm temperatures persist across the Cowboy State
  today, along with gusty winds.

- A few isolated showers cannot be ruled out late this evening
  over parts of the Bighorns as well as portions of Johnson and
  Natrona Counties.

- Record warmth prevails through Friday when a cold front moves
  through ushering in a brief return to near seasonable
  temperatures.

&&

.UPDATE...
Issued at 1220 PM MST Tue Jan 13 2026

As of noon, multiple locations have already either tied or
broken their daily high temperature record for Jan 13th. Lander
has already reached 60F breaking the previous record of 58F set
back in 1953. Other locations such as Casper, Riverton, and Big
Piney have all either broken or tied their previous records.
Locations such as Lander have the potential to reach the top 3
record highest temperatures recorded during month of January.
Lander`s current highest recorded January Temperature is 64
which may be within grasp.

The forecast has not changed all too much as the warm, breezy,
and overall quiet weather continues to prevail across the
region. One slight adjustment to the overnights forecast has
been temperatures which are warmer than many model guidances
have suggested. This may be due to winds being slightly stronger
than originally forecast leading to better mixing throughout the
atmosphere. A few isolated showers remain possible this
afternoon and evening across portions of the Bighorns along with
Johnson and Natrona Counties. Impacts from these showers are
expected to be very minimal and short lived. The remainder of
the week sees record warm continue with mainly quiet conditions
as well. A cold front still looks to make its way into the state
late Thursday into Friday with temperatures dropping closer to
seasonable values. However, this is forecast to be short lived
as high pressure will try to reassert itself over the region.
Temperatures will likely remain well above normal through the
weekend and into the start of next week.

Looking ahead, next week may be the start of the end for this
prolonged period of warm and dry conditions we have seen for
much of January. Long range guidance is showing the potent area
of high pressure that has dominated the region begin to be
suppressed south through the week. If this does come to
fruition we may see a more zonal pattern develop by the end of
the week. This pattern change may usher in increased chances for
colder temperatures along with precipitation chances. However,
being so far out a lot can change but it definitely is
something to monitor.

&&

.DISCUSSION...
Issued at 1200 AM MST Tue Jan 13 2026

Upper level ridging continue to dominate much of Western CONUS
centered around a high over northern California. As such, the
main finger of the PFJ remains to the north before it dives
south into the Great Plains and Missouri River Valley. IR
depicts ample high clouds spilling over the aforementioned ridge
across the state with no weather concerns for the foreseeable
future impact wise.

A weak mid level disturbance propagates south down the ridge
that will drop a weak frontal boundary east of the Bighorns for
Tuesday afternoon. Winds will be gusty up to 40 to 45 mph plus
for Johnson and Natrona Counties through about sunset.
Otherwise, some light snow showers expected for the northern
Bighorns earlier in the afternoon to even Casper Mountain by
evening time. Little to no accumulations expected due to the
warmer temperatures ongoing with no impacts expected.
Temperatures will remain 10 to 20 degrees warmer than average,
especially east of the Divide through Thursday ahead of the
next system.

This disturbance looks to be a bit more potent than Tuesday but
still limited in impacts. Outside of some gusty winds and cooler
temperatures, minor snow showers expected for the same general
areas of the Bighorns to Casper Mountain. Temperatures the only
impact to be felt with more seasonable temperatures for mid
January Friday at worst. Ensemble data keeps this consistent
behind the FROPA late Thursday into early Friday morning.
Otherwise, ridging builds back in even stronger for the weekend
and into much of next week. Warming and dry trend continues with
longer term outlooks seeing more of the same for the remainder
of the month.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1023 AM MST Tue Jan 13 2026

Dense cirrus overcast continues across the state today, but cigs
for most location s should stay well above MVFR limits through
the next 24 hours. Main issue today will be winds, with most
areas seeing gusts through the day. Most areas see gusts 20 to
30kts through the afternoon, with higher gusts at KCPR and KBYG.
A weak front moves through areas east of the Divide late this
afternoon and evening, turning winds from the north, but not
bringing any significant gusts. The front will bring a deck of
lower clouds and possible light rain to KCPR after 00Z, with
main chances for rain and low clouds between 02Z and 07Z. By
Wednesday morning, the high cirrus and any low clouds will be
thinning quickly, with likely SKC for Wednesday afternoon for
all sites.

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

&&

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

&&

$$

UPDATE...Dziewaltowski
DISCUSSION...Lowe
AVIATION...Straub