354
FXUS65 KRIW 110701
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
101 AM MDT Thu Jun 11 2026

.KEY MESSAGES...

- Lingering light showers continue overnight into Thursday
  morning coming to an end by sunrise. Mainly across the Bighorn
  Basin with upslope snow across the western Bighorns.

- Seasonable temperatures, breezy, low humidity, and limited
  rain and thunderstorm chances (less than 10-20 percent)
  Thursday through Sunday.

- Warming trend into next week with mainly dry conditions
  expected with the next widespread weather system by week`s
  end.

&&

.DISCUSSION...
Issued at 100 AM MDT Thu Jun 11 2026

IR shows cooling cloud tops pushing out of Montana over northern
portions of the CWA associated with the main upper level trough
starting to exit the upper Rockies to the east. The main finger
of the PFJ pushes cyclonically around the aforementioned
disturbance diving south out of eastern Montana progressing more
progressive eastward into the High and Great Plains. It is
weakening with its eastward moving due to decreasing divergence
aloft. Lingering shower activity on the backside of this system
that has affected the area the past few days stretches over the
northern Bighorn Basin to the Bighorns. Mainly in the form of
rain for lower elevations but some light snow possible for the
northern Bighorns through sunrise Thursday morning with minor
accumulations for the higher terrain with no impact to the
mountain passes heading east into the higher plains of the
state.

Northwest flow sets in place Thursday stretching from an upper
level ridge southwest of California building with increasing
convergence aloft keeping a tight gradient in the upper levels.
As such, daily afternoon/evening shower activity possible
through Saturday with daytime heating. Progressive in movement,
this shower activity will be limited in coverage and shortened
in time frame with little impacts constrained mainly to higher
elevations along and northeast of the Winds. Coverage and
confidence remain low for these daily occurrences around
10-20%. With the aforementioned system pushing east, weaker
surface convergence and gradient will be instilled across the
CWA with only breezy winds expected. The gradient will be cut
nearly in half around 3-4mb throughout the CWA giving way to
mainly westerlies up to 20-30 mph east of the Divide and 10-20
mph to the west from late morning to early evening due to
daytime heating and mixing to the surface. Improved skies
Thursday onward, clear at night and some passing clouds in the
afternoon and evening, but otherwise, a more calm weather
pattern going forward.

The upper level flow weakens even more come Sunday and into much
of next week with very minimal if any at all shower activity
diurnally. Nothing of note looks to be on the horizon until
later in the work week and following weekend as longer term
model solutions are pretty consistent with another deep
low/trough pushing in from the Pacific northwest.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 949 PM MDT Wed Jun 10 2026

VFR conditions continue through the TAF period. A cold front is
passing through central Wyoming currently, which will wash out
tonight. Rain showers along this front will dissipate overnight as
the cold front weakens. Another area of rain showers will pass
through the Bighorn Basin overnight behind the front, with another
PROB30 at KCOD and KWRL. Rain will be light enough and CIGS should
only drop to around 4kft FL keeping conditions VFR.

Wind has decreased this evening, but remains elevated at most
terminals for an hour or two to begin the TAF period. Behind the
front wind will remain strong for a few hours before dropping off
substantially overnight. Wind will be much lighter Thursday
afternoon only increasing to around 10 knots at most terminals. A
bit stronger wind will occur at KCPR beginning around 12-13Z
Thursday morning, with gusts around 25 knots through Thursday
afternoon. Frequent mountain obscuration along and behind the cold
front, especially around western mountains for the first few hours
of the TAF period.

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.

&&

$$

DISCUSSION...Lowe
AVIATION...Rowe