textproduct: Western and Central Wyoming

KEY MESSAGES

- Windy and dry today, with the next weather maker entering the region tonight.

- Widespread gusty winds 40 to 60 mph occur Thursday, stronger for the mountains. Isolated areas up to 70 mph possible.

- Strong winds and snow begins across the mountains tonight. Winter travel conditions are expected for these higher elevations Thursday, with continued snow and wind into the weekend.

UPDATE

Issued at 1247 PM MDT Wed Mar 11 2026

Today's update is just refining the details of the big event tomorrow. The overall message remains the same, however, with widespread 40 to 70 mph gusts. Have adjusted some of the specific timings of the High Wind Warnings, as the chances for gusts on the lee side of mountains could occur earlier than what was previously thought. Have also upgraded the final watches to High Wind Warnings for the Bighorn Basin and Johnson County as confidence has increased (60 to 90 percent) for gusts over 55 mph. Finally, have hoisted Winter Weather Advisories for the Tetons and Yellowstone National Park. This mainly is due to the expected combination of wind and snow. Snow totals are not overall impressive, but with wind, will bring reduced visibilities and difficult travel for those along mountain passes or doing any mountainous recreation. The period of heaviest snow is expected Thursday afternoon into the early evening, where snow rates could be around an inch an hour at times.

DISCUSSION

Issued at 357 AM MDT Wed Mar 11 2026

A brief lull is expected across the state today in what has been a busy first half of the week in terms of weather. Temperatures today are forecast to be on the cooler side with highs in the low to mid 40s east of the Divide and mid to upper 30s west of the Divide. Winds will be lighter compared to the past few days with gusts of 20 to 30 mph. Stronger gusts of 30 to 40 will be possible along the Wind Corridor from Casper to Rock Springs. Cloud cover increases through the day as a result of the next weather maker nearing the region.

All focus now shifts to 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 120 to 150 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 Thursday. The strongest winds currently look to be east of the Divide with widespread wind gusts in excess of 60 mph likely throughout much of the day Thursday. Current 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. 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. The strongest winds look to occur Thursday but gusty winds of 40 to 55 mph are still likely to persist through Saturday. 700 mb winds do weaken some Friday with speeds ranging from 40-70 kts over much of the state. Winds are expected to decrease some overnight Thursday into Friday and then again Friday into Saturday. Winds are expected to gradually increase each day during the late morning and peak during the afternoon/evening hours. There will still likely be some gusty winds through the overnight hours these days. High Wind Watches were issued during the day Tuesday and many of these Watches have been upgraded to warnings due to increased confidence. The zones that remain Watches still have the potential for strong gusts in excess of 55 mph but confidence is not as high. The eastern Bighorn Basin and Johnson County have remained watches due to there still being some uncertainty. Casper Mtn has been added to the list of High Wind Warning locations due to increased confidence in seeing criteria level wind gusts. Probabilistic guidance has highlighted these area as having a good chance 60-80% of seeing gusts of 75 mph or more. The Tetons/Gros Ventre and Salt River/Wyoming Ranges may need a wind related highlight but at this time no issuance has been made. This is due to chance of criteria winds being a coin toss with 50/50 chances of seeing gusts exceeding 75 mph. So this is something that will need to be reexamined during the day today.

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 Thursday through Saturday. This looks to funnel precipitation across northern mountain ranges such as the Absaroka, Bighorn, Teton, Gros Ventre, and northern Wind River Ranges. The most favorable mountain ranges looks to be the Absarokas, Tetons, and Gros Ventre. Models have increased QPF amounts compared to last night with large areas of amounts ranging from 0.75 to nearly 2 inches. There is one caveat to this though and that 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 may be areas with amounts nearing 3 feet mainly along the highest peaks of the most favorable mountains ranges mentioned previously. Overall, the main take away is that any snow that falls Thursday through Saturday morning 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 Thursday through Saturday across the higher elevations of northern and northwestern WY. As a result of the combination of strong gusty winds, and periods of moderate to heavy snowfall, Winter Storm Watches have been issued for these locations. The timing for these highlights is rather long starting Thursday evening through Saturday evening. There will likely be some breaks in heavy precipitation over this period. However, the combination of the strong gusty winds and heavy precipitation is a concern which warrants Watches at this time. As for the Bighorns they will see precipitation move in later in the day Thursday. 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 highlights have been issued for the Bighorns at this time but one may be needed eventually.

A cold front will gradually make its way into the area by Friday but looks to get stall across the northern/northeastern portion 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 not showing any major impacts with the current likely outcome being a few inches of snowfall Saturday night into Sunday morning.

Looking a bit ahead there are early indications for a very potent area of high pressure to build in over the western CONUS by the start of next week (March 16th). There continues to be agreement among long range models and ensembles for this to occur. It is looking increasingly possible that much of the western CONUS and Intermountain West will see a period of WELL above normal temperatures. The NBM, which usually tends to be on the more tame side when compared to other models, is showing a multi day stretch of record breaking temperatures. Highs have the potential to get into the mid to upper 70s by the middle of the week. There is a possibility for some locations to near their all time March high temperature records. 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. This situation definitely bears monitoring as we near the end of the work week and enter the weekend.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1127 AM MDT Wed Mar 11 2026

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

VFR conditions prevail at all terminals except KJAC through the forecast period. Shortwave energy reaches western Wyoming around 03Z/Thursday, which allows for a period of IFR/MVFR conditions in light snow at KJAC from 04Z-10Z/Thursday. This initial wave passes between 09Z-12Z/Thursday, with snow ending and ceilings rising to VFR. Otherwise, gusty surface wind will be the main aviation hazard. Wednesday afternoon 15-25kt speeds show a slight downturn Wednesday evening at KPNA and KBPI, while 10-22kt winds continue at KJAC and KRKS overnight. Attention then turns to increasing surface wind Thursday morning as strong mid-level wind arrives from the west. All terminals to see 25-35kt speeds develop by 15Z-18Z/Thursday. Mountain tops obscured after 02Z/Thursday.

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

Wind will be the primary aviation hazard through the forecast period. The most persistent westerly surface wind through Wednesday evening will be at KCPR and KCOD where speeds will be 15-30kts. Strong mid-level flow on the order of 50-80kts arrives from the west overnight and Thursday morning. This leads to steadily increasing surface wind speeds between 08Z-16Z/Thursday. Therefore, widespread surface wind 30G45kts occurs by 16Z-18Z/Thursday. VFR conditions prevail at all terminals. Mountain tops along the Continental Divide frequently obscured after 02Z/Thursday.

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 1247 PM MDT Wed Mar 11 2026

Widespread strong west to southwest winds 40 to 70 mph occur Wednesday night through Thursday evening. Overall, minimum RHs Thursday are 20 to 30 percent. However, wind may mix the air a bit more than current models suggest, resulting in isolated areas of drier conditions, nearing 15 percent. Driest locations will be the basins east of the Continental Divide, such as Fire Zones 275, 280, 281, and 283.

RIW WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory from midnight tonight to midnight MDT Thursday night for WYZ001-012.

High Wind Warning from 6 PM this evening to midnight MDT Thursday night for WYZ002-015.

High Wind Warning from midnight tonight to 9 PM MDT Thursday for WYZ003-008-009.

High Wind Warning from 9 AM to 9 PM MDT Thursday for WYZ004>007-010-011-016>018-030.

High Wind Warning from midnight tonight to midnight MDT Thursday night for WYZ019-020-022.