textproduct: Cheyenne

KEY MESSAGES

- Strong to Marginally Severe thunderstorms possible Monday through Thursday.

- A ridge builds late in the long term, drying the area out and perhaps breaking heat records.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 152 PM MDT Mon Jul 6 2026

A few storms are beginning to appear on radar early this afternoon over the high terrain. Storms are currently pulsey as there is very little shear in the environment to sustain them as per model soundings. As the afternoon progresses, no organized convection is anticipated as shear remains quite weak with rather unimpressive instability. Regardless of the unfavorable environment, Hi-Res guidance still has showers and storms developing off the high terrain and progressing eastward through the afternoon and evening hours. Cannot rule out a few isolated severe gusts in any showers and storms given the extremely dry low-levels. Model soundings show strong inverted-V profiles, leading to impressive DCAPE values as high as 1600 J/kg. MUCAPE values are also high enough to see some small hail in storms. The other concern given the dry low- levels is dry lightning. With relative humidity values in the teens across much of the area and high cloud bases, little, if any, precipitation will make it to the ground in these storms. Therefore, fire starts cannot be ruled out with dry lightning. Storms will dissipate and move out of the area by midnight tonight.

Tuesday will be almost a carbon copy to today as upper-level ridging continues over the Rockies. The ridge will lead to another hot day with 700 mb temperatures in the upper teens. Highs will range from the upper 80s out west, to 90s and low 100s east of the Laramie Range. Yet another weak disturbance will pass through the ridge on Tuesday, leading to storm chances during the afternoon and evening hours. The disturbance will spike mid-level moisture a bit more than Monday, leading to greater coverage of storms. The environment will be slightly more favorable for stronger storms with a bit better shear and CAPE values. Threats will be the same as today, with primarily a severe wind concern with dry low-levels and DCAPE values around 1000 J/kg. MUCAPE values will also be around 1000 J/kg so isolated large hail will also be possible with storms. Hi-Res guidance shows lingering showers and storms through much of the overnight as the disturbance is slow to move out of the area.

Flow will turn more zonal on Wednesday, flattening out the ridge and cooling temperatures off about 5 to 10 degrees. A weak disturbance moving across Wyoming will result in another round of afternoon and evening thunderstorms. The environment on Wednesday looks more favorable than Monday and Tuesday for severe storms, with the best shear and instability seen this week. This will once again lead to both a severe wind and hail threat, mainly east of the Laramie Range.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/

Issued at 152 PM MDT Mon Jul 6 2026

Afternoon thunderstorms should be ongoing through the first couple of hours of Wednesday night. This activity should tapper off before midnight leaving for a cloud filled and muggy night. Some fog could be possible in portions of the Nebraska Panhandle.

Thursday will be the last day in a stretch for mild afternoon temperatures. The remainder of the monsoon moisture and upper level lifting will keep the weather interesting, something that cannot be said for later on. Afternoon highs are likely to stay below 90. We will need to watch the western most counties for elevated fire conditions. Minimum relative humidity values will bottom out in the mid to lower teens for portions of Carbon, Albany, and Converse Counties. Winds look to be just below red flag criteria at this time however. Afternoon thunderstorms are anticipated along I-25 where MUCAPE values of around 2000 J/kg and bulk wind shear of 30-40 knots could support some organized thunderstorms. The sub cloud layer may not be as dry as it has been during the previous days allowing for more rainfall from storms along with severe weather potential.

Past Thursday and through at least Monday the upper level ridge builds with force and subsiding air starts drying and heating the area. A large portion of the Nebraska Panhandle will see +100 degree afternoons while the inner basins see 90s. The GFS has been showing some rather hot temperatures the last few days, however runs recently are trending down thankfully. The GFS does have a warm bias at longer ranges. That being said model blends are still hot and if the ridge center slides east of our area, downsloping effects can cause temperatures lee side of ridges to heat a few degrees on top of expected temperatures.

Lets talk about the fire weather outlook. Naturally this subsiding air also dries the environment efficiently and forecasts have afternoon minimum relative humidities in the teens and single digits. Being directly underneath of such a strong ridge does have a perk, the winds are typically lessened. We will likely still see 25- 35 mph wind gust during this period, but consistent winds above 25 mph may be difficult to achieve. Regardless, the antecedent conditions and critical fuels could lead to us having afternoon critical fire conditions through much of the ridging pattern days.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1130 PM MDT Mon Jul 6 2026

Gusty winds expected to start the 06Z TAF period with the western Nebraska terminals gusting 20 to 30kts. Winds slowly decrease by 09Z for all terminals before increasing for the late morning and early afternoon hours. Gusty winds continue through the remainder of the the TAF period once they increase this morning.

Primary aviation concern will be isolated to scattered showers and storms with severe storms possible across western Nebraska. All showers and storms tomorrow will have gusty and erratic winds. The Nebraska Panhandle storms are expected to be stronger in nature, with large hail and damaging wind gusts possible.

CYS WATCHES/WARNINGS/ADVISORIES

WY...None. NE...None.