677
FXUS65 KRIW 300701
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
101 AM MDT Tue Jun 30 2026

.KEY MESSAGES...

- Winds and shower activity has diminished and mainly come to
  an end into early Tuesday morning.

- Chilly temperatures by Tuesday morning under improved skies
  allowing for mid 20s to mid 30s by sunrise.

- Warming trend and mainly dry conditions for the remainder of
  the week and into the weekend with only limited shower
  activity each afternoon for northern mountains.

- Elevated fire weather conditions persist east of the Divide
  with low humidity values but only slight breeze throughout
  each afternoon/early evening.

&&

.DISCUSSION...
Issued at 100 AM MDT Tue Jun 30 2026

IR currently depicts the main upper level low pushing northeast
into the upper Great Plains as the troughing in its wake fills
with decreased divergence aloft. WV continues to show distorted
fingers of the PFJ, mainly into Canada now with little support
to the aforementioned upper level low. Radar activity has
diminished for the overnight hours as skies have improved in its
wake. This will allow for one more cold morning Tuesday allowing
for western valleys to see mid 20s to mid 30s with minor frost
likely for areas of the upper Green River for the usual suspects
between Pinedale to Bondurant.

Otherwise, southwest flow continues aloft Tuesday and Wednesday
with a couple minor shortwaves clipping the northern counties
but mainly into Montana. Each afternoon and evening will see
some limited coverage in shower activity for the northern
mountains (10-20%) with a rumble of thunder even less likely
<10% due to weak CAPE values less than 100 J/kg. This pattern
continues for the remainder of the work week as a warming trend
and mainly dry trend extends through the weekend. A more zonal
pattern by the weekend as the high to the south builds in
further north increasing convergence aloft and weaker flow.
Afternoon high temperatures back to the 80s east of the Divide
and 70s to the west for the holiday weekend with no significant
winds even to speak of. Each afternoon/early evening will see
slight breezes up to 20-25 mph for wind prone areas east of the
Divide but otherwise calm for Wyoming standards. Even with low
relative humidity values, fire weather concerns will be limited
to elevated throughout the week and weekend. This upper level
high continues to build in from the south into next week with
some longer term model ensembles showing some record heat coming
by mid to end of next week, welcome to July....

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1100 PM MDT Mon Jun 29 2026

VFR conditions across nearly all terminals for the start of the TAF
period. The one exception to this is KJAC where light rain shower
have lingered through the evening. Ceilings have gradually lifted
but are likely to linger through much of Tuesday morning. That being
said a brief period of MVFR ceilings cannot be ruled out at times.
Winds will continue to decrease across all terminals with a light
breeze through the overnight. Winds are expected to increase some to
15 to 25 knots around 14Z mainly at KCPR and KCOD. Showers begin
developing after 18Z Tuesday mainly across western and southwestern
WY. Coverage begins to spread farther north and east after 00Z
Wednesday with slight chances possible at KLND, KRIW, KWRL, and
KCPR. Overall showers are expected to be light with minimal impacts
but a few gusty outflow winds cannot be ruled nearby any developing
showers. Dry conditions return after 03Z for all terminals and
prevailing into the end of the TAF period. Mountains are likely to
be obscured especially across western WY with conditions improving
during the day Wednesday.

&&

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

&&

$$

DISCUSSION...Lowe
AVIATION...Dziewaltowski