textproduct: Western and Central Wyoming

KEY MESSAGES

- Active today with moderate snow in western Wyoming this morning and strong to high wind across much of the area.

- Another weather system brings more widespread light to moderate snow from Wednesday through Thursday morning.

- The coldest temperatures in some time move in Thursday and should last through at least Saturday.

DISCUSSION

Issued at 228 AM MST Tue Feb 17 2026

Active weather has returned to western and central Wyoming and a we have little to talk about and a lot of time to do it. Wait, strike that, reverse that, I mean we have a lot to talk about and little time to do it. For a change, we will split the discussion differently. With around an active 54 hours or so, we will tackle each day individually, talking about each hazard individually. So, let us begin.

Snow...Today and tonight...Snow has already begin across the west, with Jackson reporting snow as of 1 am along with many of the western mountains. As for this forecast, the advisories so far look to be on track and we will not make many changes this morning. Timing of the greatest impacts still looks to be through this morning, with the most before 9 am as the trough axis and cold front move through the area. One thing the day shift may consider is if they could cancel the advisory a bit early, as most of the snow may be over by noon. Amounts still look reasonable as well. There has been a bit of drop, but there is still around a 1 in 2 chance of 3 inches or more in the valleys. And this, combined with the expected strong wind, should bring enough impacts to warrant them. Amounts still look reasonable in the mountains as well, with a greater than 1 in 2 chance of 6 inches or more in the areas with the advisories. Chances of 12 inches of snow are fairly small though and largely limited to the highest elevations where impacts would be minimal. Elsewhere, we are still watching for possible brief heavy snow in Sweetwater County, this would best be handled with short term statements. As for East of the Divide, any showers would be limited except for the mountains, like the Bighorns which may see a few inches. In addition, the screaming downslope (that sounds like a good name for an alternative rock band of meteorologists) should keep any showers to a minimum. The best chance would be around Casper but anything here should be brief. A last area of concern this afternoon may be in northern Johnson County, where some snow showers may develop with the front and bring a small accumulation. Following that, there should be a lull before the next system approaches from the west after midnight, but any snow amounts should be light until Wednesday.

Wind...Today and tonight...We have already had some high wind gusts tonight, with gusts past 60 mph in Lander, Buffalo and Rock Springs already. We do have a good setup for high wind with the trough and front moving through along with some strong 700 millibar winds up to 60 knots. Around noon today, we will also have a 24 millibar northeast to southwest pressure gradient from around Gillette to Evanston. In the realm of probabilistic guidance, the NBM ensemble gives a greater than 4 in 5 chance of wind gusts past 55 mph across the warned area, with some of the more wind prone areas having a 1 in 2 chance of wind gusts past 70 mph. As a result, we will keep the high wind warnings as is. Guidance is also showing a fairly decent drop in the wind after around 5 pm, so the timing of the endings still look good as well.

Fire...Today...There will continue to be elevated fire weather across much of the area East of the Divide this afternoon. Dew points could get very low this afternoon, falling into the single digits. However, temperatures will be falling at the same time. Nevertheless, there could be brief periods of critical fire weather this afternoon in Natrona and Johnson Counties. However, we feel that wind is the greater threat right now. We have include wording of rapid fire spread this afternoon though. Conditions should improve tonight as the wind decreases.

Snow...Wednesday and Wednesday night. The second piece of energy in the form of an upper level low opening into a negatively tilted trough will swing across the area at this time. Snow should increase in intensity across western Wyoming. More highlights look likely as well, with at least a 1 in 2 chance of inches of snow or more in the Jackson and Star Valleys and at least a 5 in 6 chance of 6 inches or more across the western mountains. Like this system, the chance of 12 inches or more is less than 1 in 5 except across the highest elevations, so it looks more like advisories than warnings. In addition, there would be less wind with this system. The heaviest snow here should end early in the evening, and then our attention shifts to East of the Divide. At this point, this looks like the best chance of seeing some accumulating snow that we have had in a couple of months. For reference, the last time Casper had an inch of snow was December 27th. At our other two snow sites, Lander and Riverton, it has been since December 3rd. Snow will spread into the area starting Wednesday afternoon, although the steadiest snow still looks to fall at night. This is when low level low should turn easterly and allow more moisture to flow into the area. Most of the area has at least a 9 out of 10 chance of an inch of snow or more. The area of the heaviest snow is still somewhat in flux though, and it all depends on the movement of a mesoscale 700 millibar low and its exact position. And there are still model differences. At this point, the best chance of 3 inches or more would be east of a Worland to Riverton line. The chance of 6 inches or more looks fairly limited at this time. The best chance is near Casper where there is around a 2 in 5 chance of 6 inches or more, with the best chance in the mountains. The chance of 12 inches remains very low though. We will likely need advisories East of the Divide for Wednesday night and possibly into Thursday morning before the snow tapers off.

Following this, quieter weather should return for Friday and the weekend. A weak system may bring some further snow showers for the northwestern mountains Friday, but any amounts should be on the light side. The next question is temperatures. Temperatures on Thursday will be coldest we have seen in a while, especially at night with the fresh snow cover and decreasing wind. The air mass is Pacific though, and that will keep bitterly cold temperatures away. However, below normal temperatures look likely through at least Saturday. Following that, ridging should build back over the area. One question is for inversions in the basins, we will likely have some initially. However, they may not last. It will be late February, with the sun angle back to the equivalent of mid to late October. With any sunny skies, snow would melt quicker than if this occurred during January, and therefore weaken the inversions. However, most areas East of the Divide should have at least a few days of winter weather, something that has been sorely lacking this season.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1000 PM MST Mon Feb 16 2026

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

VFR conditions to start the TAF period at all sites with snow pushing in from Idaho. This should start at JAC within an hour of TAF issuance, followed by PNA/BPI/RKS after about 08-10Z. MVFR conditions to be had there after with likely ongoing snow (50-60%). Winds will steadily increase through the overnight hours into Tuesday morning, peaking up to 45kts at RKS after 15Z, and up to 30-35kts at the other TAF sites after around 10-12Z. Snow will taper off pretty quickly at RKS, then linger at JAC by noon and BPI/PNA through the afternoon. VFR conditions there after as winds diminish after sunset and into the overnight through Wednesday morning.

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

VFR conditions expected at all TAF sites for the entirety of the period. LND might get a shot of quick show with low confidence (10-20%) Tuesday morning if any makes it over the southern Winds with the stronger winds. Wind has pushed down for LND gusting over 50kts already, expected to last through sunrise before a slow diminish the remainder of the period. COD/CPR expected to break 50kts after 16-17Z with RIW/WRL over 40kts through the afternoon hours. Mid level ceilings scatter out after sunset Tuesday evening as winds diminish towards midnight and through the overnight into Wednesday morning.

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

FIRE WEATHER

Issued at 228 AM MST Tue Feb 17 2026

Strong wind and low humidity will bring elevated fire weather to many areas East of the Continental Divide this afternoon. Brief periods of critical fire weather will be possible this afternoon in Johnson and Natrona Counties as well. Fire weather concerns should end tonight and tomorrow as cooler and wetter weather moves into western and central Wyoming.

RIW WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 5 PM MST this afternoon for WYZ001-012>014-023-024.

High Wind Warning until 5 PM MST this afternoon for WYZ002-003- 009>011-015>018.

High Wind Warning until 7 PM MST this evening for WYZ019-020- 030.