textproduct: Western and Central Wyoming

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.