textproduct: Cheyenne

KEY MESSAGES

- Elevated fire weather conditions will continue, mainly west of I-25.

- Afternoon and evening storms, some of which may become strong to severe, will be possible most days through the weekend into next week along and east of I-25.

- Hot temperatures expected by early next week, with highs topping out in the mid 80s to mid 90s.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 121 PM MDT Fri Jul 3 2026

It is early July and the weather pattern will not differ from the norm for this time of year. Lets take a brief look aloft, at 500mb we will have zonal flow, west to east, over the region with embedded weak shortwave energy. In this pattern, with the added energy aloft, expect a continuation of isolated to widely scattered showers and thunderstorms, generally confined to locations along and east of the I-25 corridor into the Nebraska Panhandle. With forcing being limited, ample CAPE in place, between 1500 to 2500 J/kg, coupled with the energy aloft will overcome any limiting factor. As the aforementioned shortwave energy lifts northeast towards the northern portions of Nebraska by this afternoon, exiting the CWA by this evening will mark the end of the thunderstorm threat for today. Modest 0-6km shear profiles, a strong to severe thunderstorm can't be ruled out, especially north of the North Platte River. Hence, the Storm Prediction Center (SPC) slight risk (2 out of 5) in this general region. SPC has a marginal risk (1 out of 5) that extends to I-25. Winds and large hail look to be the main threat with this activity being isolated in nature. Rinse and repeat, expect a similar set up for July 4th, as a more potent VORT max digs south into the high plains the best chance for severe thunderstorms will shift towards the I-80 corridor from Laramie to Cheyenne and over towards Sidney Nebraska. SPC has increased the areal coverage of the Slight Risk to include all of western Nebraska and far southeast Wyoming, including Cheyenne. Similar chances for severe are expected with mainly strong gusty winds and large hail as the primary threats. At the tail end of this short term period, ridging will amplify into our CWA. Shifting to temperatures, with ample warm air in the mid-levels, expect highs to soar into the upper 80s to mid 90s by the tail end of this forecast period.

LONG TERM /SUNDAY THROUGH THURSDAY/

Issued at 121 PM MDT Fri Jul 3 2026

Sunday...With warm temperatures aloft, the CIN, convective inhibition, will increase markedly with 700 mb temperatures near 17 Celsius, limiting convective potential, and allowing for at best, isolated afternoon and evening thunderstorms along and east of I-25. Another warming trend begins based on 700 mb temperature trends.

Monday...Similar synoptic pattern to Sunday, with enough mid level moisture to produce isolated to widely scattered afternoon and evening thunderstorms, primarily east of I-25 where convergence at low levels will be maximized.

Tuesday...Beneficial rain appears increasingly likely as low and mid level moisture increases markedly, while a shortwave trough aloft, also known as an atmospheric perturbation, moves overhead near peak heating, sparking scattered showers and thunderstorms, especially east of a Douglas to Laramie line, with isolated convection further west in the drier airmass.

Wednesday...Shortwave ridging builds aloft and with decreasing atmospheric moisture in the low and mid levels, expect a corresponding decrease in areal coverage of showers and thunderstorms.

Thursday...Expect a slight increase in afternoon and evening shower and thunderstorm coverage, as a shortwave trough aloft passes overhead near peak heating, though coverage will be limited and scattered due to warm temperatures aloft producing some convective inhibition, also known as CIN.

Friday...GFS showing a decent discontinuity in PWAT, precipitable water values, and low and mid level moisture from dry punch across southeast Wyoming, to a buoyant and moist atmosphere across western Nebraska. Since it is still day seven, our relatively low POPS for our eastern counties looks decent for now, though later shifts may see chances for thunderstorms, particularly across western Nebraska increase for the afternoon and evening.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1133 AM MDT Fri Jul 3 2026

As with the past three days, the synoptic weather pattern is quite similar, showing a shortwave trough aloft moving across southeast Wyoming this afternoon, and to western Nebraska early this evening. A low level convergence axis, and dryline, along with some mid level instability will set up near the Wyoming and Nebraska state line this afternoon, with isolated to widely scattered showers thunderstorms first developing across southeast Wyoming between 19-22Z, and developing and increasing in areal coverage as the storms propagate into western Nebraska this evening, before ending by late evening with clearing skies thereafter.

Wyoming TAFS...VFR prevails. Based on the 16Z HRRR run, which has shown good continuity from previous runs, have high confidence in isolated to widely scattered showers and thunderstorms developing after 19Z, and affecting the area until 00Z or 01Z. Confidence is high enough in the 16Z HRRR to go with VCTS for Laramie for much of the afternoon for isolated high based thunderstorms, and to maintain PROB30 for Cheyenne for late afternoon with erratic and sudden gusts up to 35 knots. Skies will clear out this evening. Gradients and mix down winds indicate gusty winds as usual until sunset and after mid morning on Independence Day.

Nebraska TAFS...VFR prevails, with the caveat that there will be isolated to scattered showers and thunderstorms in the 21Z to 03Z timeframe, with a few of the storms late this afternoon and early evening producing erratic wind gusts of 38 to 48 knots, with possibly higher wind gusts, in excess of 50 knots, from isolated severe thunderstorms. Likelihood of strongest thunderstorm wind gusts will be at Chadron and Alliance, closer to the best low level convergence and deeper low level moisture along the 850/700 theta-e maximum ridge axis. Expect localized MVFR in visibilities due to thunderstorms. Skies will clear out after mid evening. Gusty gradient and mix down winds will occur until sunset.

CYS WATCHES/WARNINGS/ADVISORIES

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