textproduct: Cheyenne

KEY MESSAGES

- Elevated fire weather conditions will continue through the end of the work week.

- Afternoon and evening storms will be possible most days through the end of the week. A few strong to severe storms will be possible.

- Somewhat cooler, though comfortable, temperatures will occur for our bisesquicentennial, the 250th anniversary of our country on Independence Day, then a slow warming trend develops again for Sunday through Tuesday.

- Adequate moisture in the low and mid levels will help produce isolated to widely scattered afternoon and evening thunderstorms each day from Saturday through Tuesday, primarily in the deeper moisture east of Interstate 25.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 125 PM MDT Wed Jul 1 2026

Over the next several days we'll see a very similar pattern daily as evening thunderstorms, mostly for our Nebraska Panhandle zones and possibly our northern zones, will be possible, alongside a marginal risk at a storm or two becoming strong to severe, but otherwise warm and dry bringing elevated fire weather concerns.

The overall weather pattern should look largely similar each day, with ridging deepening across the Southeast US, and troughing over the Western US with a daily shortwave riding between these features. This consistent pattern should give us similar weather conditions through the end of the week, as highs on Thursday increase around 3-5 degrees with 80's west of the Laramie Range and 80's to 90's to the east. While generally dry conditons will be present as RH values mostly sit in the teens, our far eastern counties in the Nebraska Panhandle should see some moisture thanks to southerly to southeasterly flow, but it will be marginal overall with daytime RH values still down into the low to mid 20's. This moisture alongside the daily shortwaves will fuel thunderstorm chances, mostly in the Panhandle, though our northern zones in east-central Wyoming could also see some grazing showers or storms.

Each round of storms does present a marginal risk of strong to severe activity with hail and/or winds the primary hazards. A quick increase in shear this evening may help to fuel storms, but instability will be meager, though high resolution guidance has been indicating a stronger storm or two forming along the I-80 corridor near Sidney. Into Thursday we should see instability increase with around 1500-2000 J/kg of CAPE present, but shear will wane meaning storms may struggle to remain sustained or could be pulsing in nature. Friday the best instability should shift eastwards just outside of the area, but the nocturnal jet kicking up may help to sustain any storms that can pop up.

Finally, the aforementioned dry conditions will keep our fire weather conditions elevated, but thankfully surface winds are not expected to be quite strong enough to fuel critical status. The one exception could be our western zones, but as of today fuels remain in the green based on partner feedback. This likely won't be lasting much longer however with no precipitation expected anytime soon.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Issued at 125 PM MDT Wed Jul 1 2026

Independence Day...The flow aloft remains westerly, and with decent moisture in the 850-500 mb layer, and individual layers, combined with low level convergence east of I-25, we anticipate seeing isolated to widely scattered afternoon and evening thunderstorms east of I-25 in the afternoon, and over western Nebraska in the evening. All in all, the 250th anniversary of our country should see quite pleasant weather conditions across southeast Wyoming and western Nebraska, with minimal late day showers and thunderstorms, near perfect for outdoor activities. Somewhat cooler for the holiday due to more cloud cover and in a post cold frontal airmass, with maximum temperatures in the 80s, near perfect for the bisesquicentennial, 250th anniversary of our country's birth. A decent 850/700 mb theta-e ridge axis will extend across western Nebraska, so there is a possibility of isolated strong thunderstorms across the southern Nebraska Panhandle where CAPES of 2000 to 3000 J/kg will occur, though 0 to 6 km bulk shear values near 25 knots will somewhat mitigate the storms severity.

Evening temperatures will be quite pleasant on Independence Day with readings

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 to widely scattered afternoon and evening thunderstorms along and east of I-25. Another warming trend begins based on 700 mb temperature trends.

Monday-Wednesday...Similar synoptic pattern to Sunday, with decent southerly low level moisture advecting northward into our counties, especially east of I-25, though warm temperature aloft will produce enough convective inhibition, CIN, to limit afternoon and evening thunderstorms to isolated to widely scattered coverage. Temperatures will continue their warming trend based on 700 mb temperatures and the paucity, limited amount, of cloud cover. Slightly cooler on Wednesday due to an increase in mid and high level cloudiness.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 427 PM MDT Wed Jul 1 2026

Southwest flow aloft will continue, while a weather perturbation, also known as a shortwave trough aloft, passes by the terminals late this evening and to northern Nebraska by daybreak Thursday. The shortwave trough will combine with a low level convergence axis to produce isolated to scattered showers and thunderstorms late this evening across far southeast Wyoming, and over the central and southern Nebraska Panhandle from 07Z to 12Z late tonight, with clearing skies commencing thereafter.

HRRR model has been quite consistent in showing thunderstorms erupting from 07Z over the southern Nebraska panhandle, and then propagating northeastward across the central Nebraska Panhandle through 12Z Thursday. Confidence is high enough in this model solution to go with TEMPO grouping at Alliance and Sidney, with PROB30 at Scottsbluff, and VCTS at Chadron.

Nebraska TAFS...High confidence in VFR prevailing at Chadron, Alliance and Scottsbluff through the period, with the same at Sidney, except for isolated to scattered showers and thunderstorms from 07Z to 12Z, with moderate confidence in thunderstorms producing wind gusts to 35 knots with MVFR visibilities and low VFR ceilings at Sidney. Improving conditions thereafter after 12Z. A developing low level jet will aid in boosting south winds at Alliance and Chadron to 18 mph gusting to 30 mph from 06Z to 14Z.

Wyoming TAFS...High confidence in VFR. Wind gusts from 25 to 28 knots at the terminals after 14Z Thursday. Moderate confidence in MVFR ceilings and visibilities in fog occurring at the Cheyenne site from 09Z to 14Z, with clearing skies thereafter.

CYS WATCHES/WARNINGS/ADVISORIES

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