textproduct: Cheyenne

KEY MESSAGES

- Strong winds early this afternoon will gradually weaken this afternoon and evening.

- Elevated fire weather conditions will continue for much of the week ahead.

- Scattered thunderstorms late Tuesday evening will have the potential to become strong to severe, mainly in the central and southern Nebraska panhandle.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 300 PM MDT Mon Jun 29 2026

The unseasonably strong upper level low to our north continues to drive active weather across our area today. The axis of the main trough is currently on its way through the area. South to southwest flow remains out ahead of the frontal boundary, while westerly flow prevails behind. A plume of very dry air is being pulled across our area underneath the upper level low. All together, this is supporting an out-of-season high wind event and continuing fire weather concerns across the area. Winds are exceeding expectations in southeast Wyoming this afternoon. Widespread gusts over 60 mph are occurring in Platte county. The highest measured gusts was 79 mph around 1:30PM between Wheatland and Glendo. Winds are rapidly surging upward behind the slow moving frontal boundary progressing from west to east this afternoon, but the window for high winds is fairly short. Low-level height gradients are tightest right along the trough axis, which is just moving east of the I-25 corridor at the time of this writing. Therefore, we probably have another 1-2 hours of this before winds start to gradually come down through the evening hours. While relative humidity isn't really critical across most of the area, the fairly extreme winds (for this time of year) will lead to control issues. The Red Flag Warning remains in effect until 9PM for the High Plains.

While high winds will be gone by the evening, we will remain breezy for much of the night tonight as winds slowly come down. As the main parent trough lifts off to the northeast, we will see weak ridging try to nudge into our area Tuesday. Expect temperatures to be about 5 to 10F warmer than today, but fortunately, weaker gradients will mean weaker winds. Still, breezy westerlies will remain over the US- 20 corridor and northward Tuesday. Therefore, these areas were added into another Fire Weather Watch for Tuesday afternoon. As the ridge lifts northward, expect southerly winds to follow, spreading into the High Plains from south to north through the day. Confidence is lower in these winds being consistent and strong enough to classify as critical fire weather conditions. Later shifts will need to take another look at this for a possible expansion of fire weather headlines. South to southeast flow will eventually improve low-level moisture, but this may not occur until later in the evening. Meanwhile, another weaker upper level shortwave will approach the area in the southwest flow aloft. In a fairly similar setup (but overall weaker magnitude) to last night, we can expect to find another lee cyclone developing over northeast Colorado and ejecting northeastward Tuesday evening. Elevated instability will improve through the evening hours in place with another round of potent isentropic lift ahead of the approaching system. Expect some shower activity to kick up late Tuesday afternoon likely in southeast Wyoming or the central/southern Nebraska panhandle. As elevated instability increases, the probability for lightning will also increase, along with the potential for hail. The primary window for storms looks to be between about 8PM and 2AM. Hail (some of which could be large to very large) will be the primary concern, though locally heavy rainfall due to training thunderstorms will be possible too.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 300 PM MDT Mon Jun 29 2026

As we progress past Tuesday, we become stuck in Southwest flow on the front side of this ridge. The warm, dry, but smokey air from the Desert southwest and the Colorado/Utah fires will be filtering over the area for the remainder of the week. This will limit our rain chances as this dry air removes all the moisture from the surface and lower dewpoints and RH values. The models have a few shortwaves pushing into the region past Tuesday but with no moisture and very limited forcing there isn't much confidence these waves will do anything beside increase our gradient and produce the normal amount of wind through our area. Fire weather will be the biggest concern as our fuels will enter a curing state once again despite our stormy 7 days last week. Winds will be light to marginal so it may be difficult to reach Red Flag criteria for most of our area despite the low RH and curing fuels. There is another trough that may move through Friday night into Saturday morning for a possibly wet start to our 4th of July weekend plans. Looking at the global models, each one has a different intensity of forcing but there is a general uptick by the models compared to yesterday. While it still doesn't look to be a strong four corner low, the shortwave trough may be strong enough to overcome the dry air and give us some measurable precipitation. Given it is the 4th of July, we will be monitoring this set up closely and try to narrow down timing and locations for everyone.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1144 AM MDT Mon Jun 29 2026

There are a few brief showers popping up across Southeast Wyoming. This may cause KRWL to drop down into a broken ceiling around 2,000ft for a couple hours before clearing out. There is a thunderstorm developing near KTOR so be advised of that as well. Winds are expected to kick up and remain gusty through Midnight before dropping off for most areas. Then around 20z tomorrow we play this game again with potentially severe thunderstorms near KSNY, KAIA, or KCDR depending on which model you choose.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning until 9 PM MDT this evening for WYZ417>419- 430>433. Fire Weather Watch from Tuesday morning through Tuesday evening for WYZ417-418. High Wind Warning until 6 PM MDT this evening for WYZ106-107- 110. High Wind Watch until 6 PM MDT this evening for WYZ116. NE...Red Flag Warning until 9 PM MDT this evening for NEZ434>437. Fire Weather Watch from Tuesday morning through Tuesday evening for NEZ434.