textproduct: Western and Central Wyoming

KEY MESSAGES

- Winds continue through the overnight hours but slowly on the decline. - Elevated to critical fire weather will occur through Saturday, with Wednesday and Saturday looking like the most impactful days at this time.

- Record high temperatures are possible starting Wednesday, and likely Thursday through Saturday. Some locations will likely set all time March record high temperatures.

UPDATE

Issued at 1248 PM MDT Tue Mar 17 2026

Areas across central and southern WY remain windy this afternoon, with gusts in the 40 to 50 mph range. Expect the winds to die off some tonight, but another round of winds returns Wednesday and continues the rest of the week. Will be upgrading the Fire Weather Weather to a Red Flag Warning this afternoon, in effect all day Wednesday and continuing through Saturday.

DISCUSSION

Issued at 225 AM MDT Tue Mar 17 2026

Right now, it is rather windy at the humble Riverton weather abode, courtesy of a shortwave passage and some 50 knot 700 millibar winds being mixed toward the ground. The balloon launch has the potential to be rather interesting. I think I will need to put some extra weight in my shoes. It is also bringing some snow showers to the western mountains, but these should end by sunrise.

Before I get into the forecast, what comes to your mind when I mention these sports figures: Tiger Woods, Tom Brady, Babe Ruth, Michael Jordan, Wayne Gretzky and Novak Djokovic. If you said possibly the greatest or most notable of all time of their individual sports, you would be correct. And in weather terms, the strength of the ridge that will be in place across much of the western United States looks to be one of the most notable in a long time. Some models project the ridge to reach 5960 meters at 500 millibars, closer to what we would see in late spring or early summer. And the result will be a high likelihood (greater than a 4 out of 5 chance) of some locations setting their all time March record highs and possibly the earliest 80 degree high temperature in some locations by a few weeks. We have a few concerns, and we will tackle each of them individually.

FIRE...This looks to be the greatest concern at this time. Some areas did get some snow last weekend, but that will be gone in the lower elevations by today. We have a good set up for elevated to critical fire weather. Temperatures as much as 30 degrees above normal for one. In addition, it will be rather dry, with relative humidity falling into the teens and under 15 percent at times across around the southeastern half of our area. In addition, the polar jet will be close to the area. Not over the area for most part, but close enough to bring breezy to windy conditions for much of the area for much of the week. In addition, fuels are now critical for all of the lower elevations across southern Wyoming and east of the Divide. With this, we will issue a lengthy Fire Weather Watch for almost all of the critical zones from Wednesday through Saturday. The one exception is Big Horn County, where humidity will be somewhat higher and wind a bit less. But even here, elevated fire weather is likely. As for today, temperatures are expected to not be as warm and humidity a bit higher so nothing for today. Of the watch days, some zones may not be critical on Friday as the wind may decrease a bit, but I will not try to split hairs at this point. The strongest wind is expected Wednesday and again on Saturday as a cold front approaches the area. Needless to say, burning is not advisable through this period.

RECORD WARM TEMPERATURES...The very warm temperatures begin today with widespread temperatures around 70 in the lower elevations east of the Divide and 50s and 60s west of the Divide. Temperatures continue to rise through the period, likely peaking Thursday and especially on Friday. For example, the NBM ensemble gives a greater than 4 out of 5 chance of high temperatures over 80 degrees in elevations under 6000 feet on that day. The warmest March temperature I could find in our County Warning Area is 81 degrees at Worland back in 2012. Some locations even have a greater than 1 out of 3 chance of reaching 85 on Friday, such as the Bighorn Basin from Thermopolis to Lovell. We are not sure if it will get that warm, but many locations should set their all time March record high. Even more impressive that it would be 11 days earlier than the previous records, as most of the other records occurred on the last day of the month. Heat should peak on Thursday and Friday, with a slight cool down on Saturday as more clouds move in ahead of an advancing cold front.

WIND...The strongest wind is expected today with the shortwave moving over the area as well as Saturday as a cold front approaches from the north, tightening the pressure gradient. As for today, many of the wind prone areas have a greater than 4 out of 5 chance of wind gusts over 40 mph. However, as we head toward 60 mph, the chance drops to at most 1 out of 3 and these are largely in areas with little or no population of impacts. Because of this, and 700 millibar wind expected to decrease through the day, we will not issue any wind highlights. A few spots could see a gust to around 60 mph at times today though, with the best candidates in the Wind River Basin, Cody Foothills and Sweetwater County. Saturday is similar, with the usual progression of southwest wind in the favored Rock Springs to Casper locations and the post frontal northwest wind later on as the cold front moves south. Parameters are similar, with a greater than 4 out 5 chance of wind gusts past 40 mph but at most a 2 out of 5 chance of wind gusts over 55 mph. The main concern on these days would be fire weather though. Breezy conditions continue Thursday and Friday, but wind should not be as strong with the jet being pushed further northward.

RISING RIVER LEVELS...The warm weather and gusty wind will likely bring some high elevation snowmelt, especially Friday into Saturday. Flooding concerns are low at this time though. It is still March, so we still have 12 hours without sun and lows falling into the 30s should limit snowmelt at night. In addition, with the drought a lot of the water would be absorbed by the ground. However, some rising creeks and rivers are likely for the end of the week.

SUNDAY AND BEYOND...The aforementioned cold front should clear the area Sunday as the ridge weakens and moves to the east. It should knock temperatures down closer to normal levels. Unfortunately, moisture is limited so any showers would be sparse and limited to northern Wyoming. The start of next week looks mainly dry and breezy with above normal temperatures continuing as flat ridging moves across the area.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1000 PM MDT Tue Mar 17 2026

VFR conditions expected for the entirety of the period remaining dry throughout. Winds remain elevated at RIW/RKS overnight with the drainage flow of the Wind River Basin and LLJ to the south along the I-80 corridor. All other locations will increase after 15-17Z with daytime heating and mixing to the surface. Highest wind gusts up to 35kts expected at RIW/RKS after 19-20Z with all locations diminishing after 01-02Z with radiational cooling around 10kts or less. A weaker drainage wind likely for RIW with a frequent higher gust possible for Wednesday night. Some high clouds present throughout the period is the only other weather element to be had in the coming days.

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 225 AM MDT Tue Mar 17 2026

Well above normal temperatures and a gusty to strong wind will bring elevated fire weather to much of central and southern Wyoming today. However, with humidity expected to remain above 15 percent, critical fire weather is not expected. Starting Wednesday and continuing through Saturday, a combination of a gusty wind, humidity falling below 15 percent and record warm temperatures will bring a strong likelihood (greater than 80 percent) of critical fire weather across much of central and southern Wyoming, with Wednesday and Saturday possibly being the most impactful.

RIW WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from noon Wednesday to 9 PM MDT Saturday for WYZ276>283-287-289.