textproduct: Western and Central Wyoming

KEY MESSAGES

- Dry with temperatures 5 to 15 degrees above average for this time of year. Breezy winds from Rock Springs to Casper and into Johnson County as well this afternoon with frequent gusts over 30 mph.

- A weak disturbance will bring showers to portions of western and southern WY by early Saturday morning and much of the day. Light accumulating snow may be possible for the higher elevations with overall impacts remaining minimal.

- Mild and dry conditions return for Sunday into the start of next week.

- There is the potential for a system to bring colder temperatures and widespread precipitation chances by the middle of next week.

UPDATE

Issued at 1200 PM MST Fri Nov 13 2026

Status quo in the short term with increasing upper and mid level clouds west to east this afternoon and evening ahead of the next weak system. Models do indicate it digging further south, and thus, a bit less in terms of QPF amounts west of the Divide. Mainly, this system will be just a reinforcement of the not as warm air and moreso out west. The next system mid next week still much in uncertainty on details, but will push in late Tuesday evening/night and start impacts west of the Divide overnight with a transition east Wednesday. Colder temperatures of higher confidence but precipitation amounts and type will be dependent on these temperatures and track of the system itself. Stay tuned for details and updated forecasts in the coming days.

DISCUSSION

Issued at 213 AM MST Fri Nov 13 2026

A fairly quiet day is forecast across the Cowboy State for Friday. Temperatures to no surprise remain mild with values 10 to 15 degrees above normal. Highs are expected to reach the upper 50s to low 60s east of the Divide and low to mid 50s for the west. Aside from mild temperatures, winds will increase in the afternoon ahead of an approaching disturbance. These winds will be mostly restricted to the Wind Corridor from Rock Springs to Casper and into Johnson County. Speeds are likely to range from 15 to 25 mph with gusts of 30 to 40 mph a few gusts up to 45 mph cannot be ruled out.

The aforementioned disturbance is in association with a trough that will begin to make its way onshore Friday afternoon. This disturbance continues to weaken and become more unorganized which will lead to lesser impacts for the area. Showers begin to move into western WY Saturday morning with much of the moisture staying across the higher elevations. That being said showers will be possible for the lower elevations of western WY throughout the day. Temperatures should be cold enough to support snow showers during the morning before warming temperatures transition any low elevation precipitation into rain. Some showers may be possible across southern WY as well but similar to other low elevation locations, amounts will be minimal. East of the Divide will be quite similar to what has occurred over the past week or so. Mild temperatures and mostly dry conditions prevail as southwesterly flow will be unfavorable for showers. Due to the unorganized nature of the system much of the precipitation will end by Sunday. Overall, a coating to maybe an inch of snow is possible across the higher elevations of western WY. A very wet coating of snow cannot be ruled out for some low elevation locations Saturday morning but the warm temperatures should quickly melt any accumulation by the afternoon. Per usual locations east of the Divide will remain dry with mild temperatures. Breezy winds will be possible across the same locations as Friday.

The remainder of the weekend sees cooler but still above normal temperatures with mostly dry conditions. Above normal temperatures and dry conditions persist into the start of next week as ridging builds back in over the Intermountain West. Another disturbance is lurking around the corner for the middle of the week. Models show a trough digs across the western CONUS Monday before moving into the Great Basin by Tuesday. This disturbance makes its way over the area Tuesday into Wednesday and then quickly ejects into the Northern High Plains. The timing of this may be a little quick with models possibly slowing the trajectory by 12 to 24 hours as we get closer. At this time, the main things to watch will be the track and how well this system can organize. Models currently show it remaining mostly unorganized until it begins to leave the area where a more defined low begins to develop but by then it will be to the northeast of the area. If things stand, the greatest impacts look to be focused across western and northwestern WY. These locations would have the most favorable dynamics to see steady precipitation. As for other locations, there does look to be the possibility for some widespread precipitation but it would likely be on the lighter side. Temperatures may hinder any daytime snowfall mainly for locations east of the Divide. Overall, chances for accumulating snowfall will be the best across the higher and even lower elevations of western WY. Probabilistic guidance is currently showing a 30-50% chance for an inch or more of accumulating snow for the western valleys such as Star Valley and Jackson Hole. The higher elevation mountains of western WY have a 30-60% of 3 or more inches of snow. Other locations see much lower chances for any accumulating snowfall due to less favorable dynamics and warmer temperatures. However, things are not set in stone and could possibly change as we head through the weekend, it definitely bears monitoring.

Colder more seasonable temperatures look to follow in behind this system as it moves out of the region for the second half of the week. Longer range models show another disturbance quickly move in for the end of the work week into the weekend. As mentioned in yesterday's discussion, this system is looking more potent. There looks to be greater potential for widespread precipitation possibly in the form of snow for mostly all elevations. Not to be a pessimist especially for those east of the Divide but with how things have gone the past winter, its best not to get overly excited for 200+ hour model depictions. So stay tuned as we wait and see what kind of trends may develop over the next few days.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1034 AM MST Fri Nov 13 2026

West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals.

Anticipate dry and VFR flight conditions through at least 08Z Saturday with increasing high clouds. A weather system approaches southwest Wyoming overnight and brings a 20 to 40 percent chance of light rain or snow to all West of the Divide terminals early Saturday. Confidence in the onset and duration of precipitation is rather low, so opted for PROB30 groups at this times. MVFR visibilities or ceilings are possible with the precipitation, with higher confidence of reduced flight conditions at KJAC, KBPI, and KPNA. Frequent mountain obscurations are expected from 08Z Saturday through the end of the TAF period. Otherwise, winds are forecast to be 12 kts or less at KJAC, KBPI, and KPNA. A south to southwest breeze is forecast at KRKS Friday afternoon.

East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals.

Confidence is rather high (90 percent or greater) in VFR flight conditions through 18Z Saturday with increasing mid to high level clouds. Winds are forecast to be 12 kts or less at KCOD, KRIW, KLND, and KWRL the entire TAF period. At KCPR, expect breezy southwest winds with gusts in the 25 kt to 30 kt range through sunset before decreasing to 12 kts or less. However, an occasional gust around 40 kts cannot be ruled out at KCPR Friday afternoon.

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.