textproduct: Cheyenne

KEY MESSAGES

- Elevated fire weather conditions will continue for the week ahead with warm and dry weather.

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

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 210 AM MDT Wed Jul 1 2026

With a shortwave moving out of the area, dry and warm air will move in behind it and settle across the region. 700 mb temperatures will climb into the low teens with mid-level relative humidity falling to about 30 percent. The dry air will lead to a sunny day across the area, with highs around average for this time of year. Hi-Res guidance does show the potential for a few high terrain gusty showers developing late in the afternoon. Given the dry surface, little to no precipitation will make it to the ground, but also cannot rule out a severe wind gust with DCAPE values around 1000 J/kg. As the evening progresses, instability will build with a weak disturbance passing aloft. GFS soundings show decent CAPE values around midnight in the southern Nebraska panhandle. Hi-Res guidance agrees with this, showing some nocturnal convection developing around midnight and continuing to move through the panhandle through the early morning hours. Severe storms are not likely given the parameters on model soundings, but a few strong storms could be possible.

Similar weather conditions are possible for Thursday, albeit a few degrees hotter. Most models still show mostly sunny skies throughout much of the day, with the potential for gusty showers during the afternoon. Model soundings do show moderate amounts of instability in the Nebraska panhandle during the afternoon. With MUCAPE values around 2000 J/kg, large hail could be possible. DCAPE values are also around 1500 J/kg leading to a severe wind threat as well. Most Hi-Res guidance currently keeps most of the storms outside of the CWA. This is likely due to the weakly sheared environment. However, if storms do form Thursday in the Nebraska panhandle, they will have the potential to be severe.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 300 PM MDT Tue Jun 30 2026

Friday...Although another weak perturbation, or shortwave trough, will lie across western Nebraska in the late afternoon, with adequate low and mid level moisture, the 850/700 mb theta-e ridge axis will be a bit further east compared to Thursday, though we will need to watch for decent low level convergence across the eastern row of counties in the Nebraska Panhandle for isolated strong to possibly severe thunderstorms. With less cloud cover compared to Thursday, the warming trend will continue.

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.

Sunday...With warm temperatures aloft, the CIN, convective inhibition, will increase markedly with 700 mb temperatures near 18 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 and Tuesday...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. Temperatures will continue their warming trend based on 700 mb temperatures and the paucity, limited amount, of cloud cover.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 534 AM MDT Wed Jul 1 2026

Minimal aviation impacts are expected during the day with mostly sunny skies and relatively light winds. Smoke will likely be seen aloft throughout the day, but should not cause significant visibility reductions at terminals. Heading into the overnight hours, scattered storms will be possible at western Nebraska terminals that could cause impacts.

CYS WATCHES/WARNINGS/ADVISORIES

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