textproduct: Western and Central Wyoming

KEY MESSAGES

- Somewhat cooler but still warm today with a gusty to strong wind along with elevated to critical fire weather.

- Remaining warm and breezy on Friday with elevated to near critical fire weather continuing.

- It will turn much cooler Sunday and Monday with a decent chance of rain and snow across much of the area. Details on placement of the heaviest rain and snow as well as amounts remain uncertain.

DISCUSSION

Issued at 215 AM MDT Thu May 14 2026

You may remember tongue twisters from when you were younger, like "Peter Piper Picked A Peck of Pickled Peppers." Well, we will have a shorter tongue twister do describe the weather over the next 7 days. It is "Wyoming Weather Whiplash." If dare you to say it fast three times. By the time we get to the weekend, we will be feeling the whiplash compared to the unseasonably warm weather we have had.

And it was very warm yesterday. All nine of our climate stations had record high temperatures yesterday. Three (Riverton, Buffalo and Casper), had their earliest occurrence of 90 degrees in the calendar year. And Buffalo set an all time high for the month of May. Temperatures will remain above normal today, although about 10 to 20 degrees cooler for most behind the passage of the cold front that brought the gusty showers and thunderstorms yesterday.

The main concerns today will be wind and fire weather. I an giving though to possible wind highlights for the Cody Foothills. The area will be in the right front quadrant of an 100 knot jet streak to add some downward forcing. The 700 millibar forecasts are showing an area of 50 to 55 knot wind in northern portions of the zone. However, things don't look as cut and dry as yesterday. The area of 700 millibar wind is smaller. In addition, it only lasts for about 4 to 8 hours. HREF ensemble guidance only gives around a 1 in 3 chance of wind gusts over 55 mph as well and this is mainly for areas very close to the Absarokas where impacts are limited, especially in regards to travel. If may issue something sometime this morning but this will be a game time decision. Elsewhere, there will be a gusty wind but high wind should not occur. In addition, relative humidity will remain very low, under 10 percent in some locations. Elevated to near critical fire weather remains very likely for most locations as a result. Most wind should decrease after sunset as the wind decouples.

Friday at this point looks fairly similar. Although with somewhat less 700 millibar wind, high wind looks unlikely. Relative humidity will remain very low though, so this looks like another day of elevated to near critical fire weather.

The whiplash will begin Saturday. This looks like another day of above normal temperatures, although with somewhat less wind. However, some southern stream moisture will begin to move into southern Wyoming on Saturday with a chance of a few showers and thunderstorms. At the same time, an upper level low will be moving in from the Pacific northwest. Most other portions of the state should remain dry during the daylight hours on Saturday. Precipitation starts to spread into the area Saturday night and especially on Sunday. As for details, there are a few moving parts with this system. In addition, some models open the low into a trough and are more progressive with it, moving it out on Monday while others cut it off and keep unsettled weather over the area into Tuesday. So details on placement of the heaviest precipitation and amounts remain very much in flux. And, this system has a decent amount of cold air with it. So, some of it will be in the form of slow, even in the lower elevations. With 700 millibar temperatures falling to minus 7, most areas will have a chance. We may need some highlights for the mountains, where the NBM ensemble gives a greater than 1 in 2 chance of over 6 inches of snow, especially above 8500 feet. Amounts in the lower elevations are impossible to determine right now. With the recent very warm temperatures, the ground is very warm and a lot of snow may melt on contact, especially on paved surfaces. Anything that falls during the day will likely melt on roads, since we will be less than 5 weeks from the summer solstice and the sun is very strong. It will also be very elevation dependent, with most accumulation largely above 6000 feet. However, with some high temperatures 40 to 50 degrees colder on Sunday and Monday when compared to yesterday, it will be weather whiplash for most of western and central Wyoming.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 404 AM MDT Thu May 14 2026

VFR conditions expected throughout the entirety of the period. Wind will increase through the day with the highest wind gusts in vicinity of KCOD where gusts to 40 knots are possible. Gusts up to 35 knots at CPR and 25-30 knots at all other locations. Winds will diminish towards sunset after 02-03Z as winds decouple West of the Divide as well as in vicinity of KWRL. Winds will weaken but still breezy up to 25kts at COD/RIW/LND, although wind will decrease somewhat here as well.

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 215 AM MDT Thu May 14 2026

Temperatures will be cooler today. However, a combination of a gusty to strong wind and relative humidity falling under 15 percent will bring another day of elevated to near critical fire weather. Friday looks similar although wind may be somewhat lighter. Wind should finally decrease and humidity should begin to rise on Saturday and bring some improvement in conditions.

RIW WATCHES/WARNINGS/ADVISORIES

None.