890
FXUS65 KRIW 301030
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
430 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. Better chance
coming in from the southwest later in the evening towards sunset
from Sweetwater to Fremont Counties (30-40%). 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 /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 430 AM MDT Tue Jun 30 2026

VFR conditions expected throughout the entirety of the period.
Weaker winds to start the period, expecting gusts up to 25kts
after 14Z. Other locations east of the Divide along with RKS/PNA
cold see weaker outflows from some limited shower activity
after 21-22Z through around 02-03Z, latest at CPR until 07Z
where frequent gusts possible through. Confidence is low on
precipitation on station with its isolated coverage (~10-15%)
carrying only VCSH. Otherwise, winds diminish and some scattered
mid level clouds through the overnight hours into Wednesday.

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...Lowe
AVIATION...Lowe