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 /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 433 AM MST Tue Feb 17 2026

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

An incoming system will bring snow and wind to the area through much of the period. MVFR to IFR impacts are expected, especially through the morning hours when snow is most persistent. West to southwest wind will continue to ramp up during this time, with gusts to 30 knots at KJAC, and 35 to 45 knots at KBPI, KPNA, and KRKS. Wind will decrease between 00Z and 03Z Wednesday with lighter wind expected through the end of the period. VFR conditions are expected at all terminals by sunset. However, the next system will follow quickly, returning snow and MVFR conditions to KJAC after 05Z.

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

A system will bring wind and some precipitation impacts to the area through much of the period. Wind gusts of 40 to 50 knots will be widespread, generally out of the west or southwest, strongest this morning through 00Z Wednesday. Rain and snow is largely expected to remain over the mountains, though brief impacts are possible at KCPR and KLND this morning. Skies will become scattered or few by 00Z, with lighter wind then expected through the rest of the period.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC 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.