textproduct: Western and Central Wyoming

KEY MESSAGES

- Strong winds gusting in excess of 60 mph will continue for areas along and east of the Continental Divide through sunset, with localized gusts to 70 mph in wind prone locations.

- The highest elevation mountains (above 9000 ft) in western Wyoming will see multiple rounds of light to moderate snow over the next 3 days. Expect wintry conditions if traveling over area passes.

- A cold front is forecast to bring light accumulating snow to lower elevations of central and northern WY Saturday night into Sunday.

- Confidence is high (90%) for well above average temperatures for the middle of next week, with record-breaking heat possible.

UPDATE

Issued at 1225 PM MDT Thu Mar 12 2026

The forecast for today remains on track, but the air mass has been a bit drier than expected, and snow is likely to be on the lower side of forecasts for today and tonight. Snow will still affect the highest elevation mountains (above 9000 ft) in western Wyoming. Expect multiple rounds of light to moderate snow over the next few days if recreating in the higher terrain, and wintry conditions if traveling over area passes during this timeframe.

Winds from the strong jet stream aloft continue to mix down to the surface this afternoon and evening. Lots of reports of strong winds have been received already, with gusts in excess of 60 mph being common, and several 70+ mph reports. A few wind prone locations have gusted 80 to 90 mph. High Wind Warnings continue for areas along and east of the Continental Divide through sunset. Although relative humidities will remain in the 20 to 30 percent range (and hence no Red Flag Warnings), fire weather danger is elevated due to the notably strong winds today, and fine fuels are of particular concern. Winds decrease notably after sunset, but will remain elevated and breezy compared to a typical night.

DISCUSSION

Issued at 244 AM MDT Thu Mar 12 2026

After a rather quiet and uneventful Wednesday all focus now shifts to the next weather maker that will bring heavy precipitation across northern mountains and widespread strong gusty winds. The main surface low associated with this system will remain well to the north of the state. However, the key component of this system as a whole is a very potent jet that will set up across the northern half of the CONUS. 500 mb winds look very robust with a strong jet streak of 100 to 130 kts stretching from southwestern Canada down into the northern High Plains. As a result, the pressure gradient will become very tight across the region. 700 mb winds of 50-90 kts will spread across nearly all of the state today. The strongest winds continue to look as they will set up east of the Divide with widespread wind gusts in excess of 60 mph likely throughout much of the day Thursday. Probabilistic guidance gives nearly all lower elevation locations east of the Divide a solid 60-80% chance of seeing gusts in excess of 70 mph. The only exception to this is portions of Johnson County and the eastern Bighorn Basin where confidence is not as high (20-50%). Higher elevations will see very potent wind gusts, likely in excess of 80 mph at times. Chances to see gusts in excess of 80 mph range from 60-90% over much of the Absarokas, Bighorns, Owl Creek Mtns, Bridger Mtns, Wind River, Green Mtns, Rattlesnake Range, and Casper Mtn. This likely creates dangerous conditions along mountain highways/routes such as Powder River/Granite Passes, South Pass, and Chief Joseph (Wyoming Highway 296) along with many others. Hi-res models have continued to show the potential for a rather vigorous mtn wave developing along the eastern slopes of the Wind River and Absaroka Ranges. The timing of this looks to be around the late morning hours into the mid afternoon. The main areas of concern look to be along the Cody Foothill, Lander Foothills, upper Wind River Basin, south along South Pass, and possibly stretching far enough south to cross parts of I-80 in Sweetwater County. There is the potential for periodic gusts of 80 mph occurring in the aforementioned locations with chances around 30-60%. South Pass would likely see stronger winds possibly in excess of 90 mph at times with chances around 50% for that to occur. Another location that may see some strong winds is parts of Lincoln, Sublette, and western Sweetwater Counties. Hi-res models have shown a recent increase in 700 mb winds over this area ranging around 50-60 kts. The confidence in wind gusts exceeding 55 mph is not really there with chances only sitting around 30-50%. Winds look to weaken some overnight into Friday but widespread breezy to gusty winds of 25 to 40 mph likely persist. 700 mb winds do weaken some Friday with speeds ranging from 30-60 kts over much of the state. Winds are expected to gradually increase during the late morning hours Friday and peak during the afternoon/evening hours before once again decreasing overnight. Saturday may see strong winds return as gradients tighten with a nearing cold front. At this time 700 mb winds look to range from 50 to 70 kts which could translate to near high wind criteria at the surface. So high wind highlights may be needed once again Saturday but at this time there is not enough confidence. High Wind Warnings remain in place through late this evening across nearly all high and low elevations east of the Divide.

The other aspect of this upcoming weather event will be a prolonged period of precipitation across the higher elevations of northern and central WY. Predominately westerly/northwesterly flow will persist over the region through Saturday. This will funnel moisture across northern mountain ranges such as the Absaroka, Bighorn, Teton, Gros Ventre, and northern Wind River Ranges. PWATS look to be well above normal values with percentages of 120-160% above normal spread over western and northern WY. Models have continued to increase QPF amounts compared to with large splotches ranging from 1 to 2 inches. Some of the higher peaks may even see liquid amounts nearing 3 inches. There is one caveat to this though and its a very important one, it is very mild temperatures across much of the region. 700 mb temperatures are currently forecast to range from -2 to -5C which would keep snow levels at around 7500- 8000 ft during that daytime. That being said, snow ratios would still be rather low even above 8000 ft. Models are showing snow ratios around 12:1 to 10:1 in the best situations with ratios further decreasing after Friday and Saturday. So currently, snowfall amounts as a result of the prolonged period of favorable flow mostly range from 1 to 2 feet. There looks to be areas with amounts of 3 feet or more mainly along the highest peaks of the most favorable mountains ranges such as the Absarokas, Teton, Gros Ventre, and northern Wind River Ranges. Overall, the main take away is that snowfall through Saturday will likely be very wet and heavy. Now combine the very strong winds that are forecast across the higher elevations with moderate to heavy snowfall. There is the potential for very hazardous travel conditions to occur at times through Saturday across the higher elevations of northern and northwestern WY. As for the Bighorns, they will see precipitation move in later today. Currently the best chances for amounts of a foot or more look to remain across the northern half of the range and above 8,500 feet. No winter highlights have been issued for the Bighorns at this time.

Little has changed in regard to the timing and track of the cold front that moves into the state Friday and gets hung up across the northern half of the state. The front does look to finally make its way south Saturday. Behind the front there does look to be much colder air that will filter into the region. Along with the colder temperatures there will be chances for widespread precipitation across all elevations mainly east of the Divide. Models are showing snow makes its way south late Saturday into the early morning hours Sunday. There does look to be some low elevation locations at this time that may see near Winter Weather Advisory amounts (3"). The best chances 30-60% is expected to be along the eastern slopes of the Absarokas including the Cody Foothills and from Johnson County south into Natrona County. So this bears watching to see if any low elevations winter highlights may be warranted.

As mentioned over the past few days, there remains strong confidence in a very anomalously potent area of high pressure building in over the western CONUS by next week (March 16th). There continues to be agreement among long range models and ensembles for this to occur. As of writing this, probabilistic guidance suggest a 40-70% chance of seeing highs exceeding 75 degrees across the lower elevations east of the Divide. For reference of how anomalous this would be, the all time March high temperature at Lander, which has records going back to 1891 is 76F. There is increasing possibility for many locations to near or break their all time March high temperature records. This would also be quite the prolonged period of anomalous heat, likely persisting into next weekend. Now this is still quite a ways out but with each passing day chances for this occurring continue to grow. The other aspect of this is the potential for rapid snow melt if overnight temperatures are able to remain above freezing across the higher elevations. The greatest concern would be over western and central mountains where there is near to slightly above normal snow pack. The concern may increase further, especially with an additional foot or more of heavy wet snow likely to fall over these mountains with this current system. This situation definitely bears monitoring as we near the end of the work week and enter the weekend. Looking back the groundhog may of actually been right with his prediction of another 6 weeks of winter. The only thing is it may not of been the normal Wyoming winter weather and instead it was another 6 weeks of this years record breaking warm winter weather.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1152 AM MDT Thu Mar 12 2026

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

The primary aviation hazard will be gusty westerly surface wind at all terminals through the forecast period. Widespread 20-30kt sustained surface wind with gusts 30-40kts will be common through the afternoon. There is some drop-off in speeds tonight, but not much. Mountain snow showers could occasionally spread downstream into KJAC overnight, but confidence is not high. Therefore, have a few PROB30 groups at KJAC to address low-end VFR potential and light snow. Westerly wind speeds do increase again 15Z-17Z/Friday with frequent gusts 30-40kts. Mountain tops remain obscured.

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

Wind is the story today. Widespread westerly surface wind 30-40kts gusting 50-60kts through early Thursday evening. Speeds decrease 01Z- 04Z/Friday, but remain 20-35kts across the central terminals much of the night. Some high-resolution models indicate a decoupling at KRIW and KLND, but confidence in that solution is low. A frontal boundary sags south through KCOD between 01Z-03Z/Friday and reaches KWRL before 06Z/Friday, with a lighter northerly wind to follow at each terminal. Expect all but KWRL to see westerly 20-40kt surface wind develop 15Z-17Z/Friday. Mountain tops along the Continental Divide remain obscured throughout the period.

Please see the Aviation Weather Center and/or CWSU ZLC and ZDV for the latest information on icing and turbulence forecasts.

RIW WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until midnight MDT tonight for WYZ001- 012.

High Wind Warning until midnight MDT tonight for WYZ002-015- 019-020-022.

High Wind Warning until 9 PM MDT this evening for WYZ003>011- 016>018-030.