textproduct: Western and Central Wyoming

KEY MESSAGES

- A Dense Fog Advisory has been issued for portions of Natrona County through 9 AM this morning. Patchy areas of dense fog have reduced visibilities below a quarter mile in some locations in/around Casper and east along I-25.

- A few light rain/snow showers across portions of western and southern WY today. The rest of the area should remain dry with mild temperatures persisting.

- Mild and dry conditions return for the entire area by Sunday and into the start of the work week.

- A system may bring precipitation chances to portions of the state by Tuesday/Wednesday. Cooler temperatures could support snowfall across the western valleys with accumulating snowfall across the higher elevations.

- Much colder temperatures build into the region for the second half of the week with values returning to seasonable or even slightly below normal.

DISCUSSION

Issued at 138 AM MST Sat Nov 14 2026

Above normal temperatures and mostly quiet weather will prevail across much of the Cowboy State this weekend. For Saturday a nearing trough will try to bring some precipitation chances to portions of southern and western WY. However, due to it being so unorganized and the bulk of the energy tracking farther south, much of the state will remain dry. A few rain/snow showers cannot be ruled out this morning into the early afternoon hours today. The best chances 30- 60% will be across far southwestern and western WY with lesser chances elsewhere. The higher elevations of western WY may see a very light coating of snow but overall accumulations will be little to non existent. Locations east of the Divide will remain dry with breaks in the cloud cover by the afternoon likely allowing for sunshine to break through. Temperatures will be in the mid to upper 50s east of the Divide and mid to upper 40s west of the Divide. Sunday is looking quite nice with clouds decreasing allowing for plenty of sunshine throughout the day. Temperatures are expected to remain around the same values as Saturday. Winds do look to increase across the Wind Corridor by the afternoon from Rock Springs to Casper. Speeds of 15 to 25 mph with gusts of 30 to 40 mph will be likely during the afternoon.

The start of the work week will see pleasant, dry, and mild conditions continue across the region. Temperatures will be similar to Sunday with breezy winds once again expected in the afternoon from Casper to Rock Springs. Another disturbance looks to be on the horizon for late Tuesday afternoon into Wednesday. This disturbance is in association with a trough that digs across the western CONUS starting late Monday. However, energy with this trough is likely to struggle to organize as it tracks east throughout the day Tuesday. Models do not really show any well defined closed low developing which will limit impacts. Precipitation chances overall do look much better than this most recent system, especially for the higher elevation mountains and western WY. Along with better precipitation chances this disturbance will bring cooler and seasonable temperatures to the area.

The current forecast is for showers to move into western WY late Tuesday behind a cold front that will gradually sweep west to east over the region. Temperatures may be a little too warm for snow to initially fall for the western valleys but they should cool quite quickly allowing for a transition over to snow. Snow showers will be possible through the overnight Tuesday into Wednesday across portions of western and southern WY. Some precipitation may make it across the Divide but dynamics may not be the most favorable. So at this time the best chances for precipitation will remain over western and southern WY along with the higher elevation mountains of western, central, and northern WY. Winds are another aspect to monitor as initially models showed a potent area of 700 mb winds move over central WY. However, the recent trends have lowered these winds, that being said some gusty winds of 30 to 40 mph still look possible Tuesday afternoon along the Wind Corridor from Rock Springs to Casper. As for snow accumulation probabilistic guidance is showing western valleys having a 30-60% chance of at least 1 inch of snow. The higher elevations of the Teton, Gros Ventre, Wyoming/Salt River, and western Wind River Ranges have a 50-70% of 3 or more inches of snow accumulation. Other high elevations such as the Absaroka and Bighorn Ranges have a 20-50% of seeing 3 inches. Models are trying to show the chance for snow light snowfall across the lower elevations of central and northern WY. However, the dynamics are not very favorable as mentioned before so chances for any snow accumulation at this time look very low. The system moves out by Wednesday afternoon leaving behind much colder temperatures. If any snow accumulation does occur overnight temperatures may be even colder than what is currently forecast. Currently Wednesday nights lows look to get into the 20s east of the Divide and teens west of the Divide. As mentioned earlier, especially for western valleys if snow accumulation does occur these lows could be even colder. There remains the potential for another possibly more potent system to impact the region by the end of the work week into the weekend. However, being so far out and with how volatile the current set up is its tough to know what to expect at this time. Long range models continue to flip flop with not much consensus at this time. So, stay tuned as it is looking like the upcoming workweek may be quite eventful for the Cowboy State.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 342 AM MST Sat Nov 14 2026

Largely VFR conditions will continue through 12Z Sunday for most TAF sites. There are a few exceptions though. In vicinity of KJAC and KRKS, a weakening weather system may bring some showers, largely before 20Z that could bring some brief MVFR visibilities and ceilings. In vicinity of KCPR, there is around a 20 percent chance that fog could move in from the west and bring IFR ceilings until around 16Z this morning. We did not include at this time, but included a lower cloud deck for now. Wind should remain under 11 knots for most TAF sites, but wind gusts to 20 knots are possible in vicinity of KCPR and KRKS this afternoon before decreasing after sunset.

RIW WATCHES/WARNINGS/ADVISORIES

Dense Fog Advisory until 9 AM MST this morning for WYZ020.