textproduct: Cheyenne

KEY MESSAGES

- Severe weather chances wrap up Thursday night with a slight risk primarily for our northeastern zones.

- Near record high temperatures and near critical fire weather conditions are anticipated this weekend.

- Expect a quick cool down on Monday before heat builds back into the area towards the middle of next week.

- There is potential for widespread critical fire weather conditions on Tuesday and Wednesday.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 239 PM MDT Thu Jun 4 2026

Current observations from across the area position the dryline roughly along the Wyoming/Nebraska border. A cumulus field with a few spotty showers have developed behind the dryline as model soundings still show a weakly capped environment in the Nebraska panhandle early this afternoon. This cap should erode away soon and as these showers trek eastward into a more favorable environment, a few isolated thunderstorms could develop. Cannot rule out these storms being severe, with meso analysis showing about 1500 J/kg of CAPE in the panhandle along with pretty good effective shear. Both large hail and severe wind gusts could be possible given the MUCAPE and DCAPE values across the Nebraska panhandle. For areas behind the dryline, strong inverted-v sounding profiles point to gusty showers this afternoon. With how dry the low and mid-levels are, its likely not much, if any, precipitation will make it the ground. Instead, rogue severe wind gusts will be possible in these dry microbursts. Heading into the overnight hours, model soundings from the GFS show pretty good elevated convection will exist as well as a surge of low-level moisture into the northern Nebraska panhandle and Niobrara County. As a result, some strong storms will be possible overnight in the aforementioned areas.

Much quieter weather is expected for Friday as zonal flow dominates the upper-levels of the Rockies. Dry air aloft will stay in place, leading to a mostly sunny day across the area. Temperatures will remain on the warm side with highs in the 80s across the CWA. Luckily a breeze throughout the day will help the warm air from feeling stagnant.

LONG TERM /SATURDAY THROUGH THURSDAY/

Issued at 239 PM MDT Thu Jun 4 2026

Hot temperatures will prevail this weekend. A strong upper level low pushing into the Pacific northwest will amplify a powerful ridge over the Rockies and Plains over the weekend. Warm air will surge northward, sending temperatures well above seasonal averages. Saturday will be the hottest day of the period, and ensemble members have continued to trend more aggressive on the hot temperatures. NAEFS mean 700-mb temperatures climb to around +15 to +17C across the area, which will range from the climatological 90th to 99th percentile across the area. Over most of the area, highs will easily be 15 to 20F above seasonal averages, with the largest anomalies around the Chadron area. Most locations will be within a few degrees of daily record highs, but no records are currently forecast. The Rawlins to Cheyenne corridor can expect highs in the mid 80s to close to 90 degrees, while even hotter temperatures will show up in the lower elevations north and east of Cheyenne. Probabilities for 100 degree temperatures are around 50 to 60% in Torrington, Scottsbluff, and Chadron, and around 20 to 30% in Sidney and Alliance. Despite a dry airmass in place, the heat should be sufficient to kick off high-based shower and thunderstorm activity. There is some uncertainty on the location of the dryline Saturday afternoon, which will determine whether this activity will be able to produce notable rainfall, or if it will just be the typical dry microburst threat. Sunday will be similar to Saturday. Temperatures will be not quite as hot as the Pacific trough approaches from the west, but expect highs well above seasonal averages once again. The convective threat will again be determined by the exact position of the dryline, which could vary somewhere between entirely east of our area, and closer to the WY/NE state line.

Expect a modest cool down on Monday as the shortwave trough ejects to our north. However, model guidance has trended weaker and further north with this cold front. As a result, highs may actually remain above seasonal averages on Monday, but just by perhaps 5 or so degrees. The powerful ridge will amplify once again Tuesday through the middle of next week as yet another trough dives into the West Coast. Therefore, expect highs to surge to near record high values yet again for Tuesday, Wednesday, and possibly beyond. Ensembles are not very optimistic for widespread precipitation at any point during the forecast period. Fire weather concerns will be elevated to near critical for most of the next week thanks to the hot temperatures and dry airmass expected to remain in place. Tuesday and Wednesday have the potential to be particularly concerning fire weather days due to increasing southwest winds aloft in between the west coast trough and the powerful ridge over the central Plains.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 542 PM MDT Thu Jun 4 2026

Thunderstorms are beginning to move out of the area. At CYS, BFF, AIA, and SNY, VIS reductions are no longer anticipated, but we may see some gusty winds and lightning in the vicinity. CDR still has potential to see a VIS drop with locally heavy rainfall.

The wind direction will be messy overnight. Variable winds are possible at times due to the departing thunderstorm activity. Then, a frontal boundary will slip through the area, turning winds to the northwest, north, or northeast. This may be gusty at times around the frontal passage. There is also the possibility for low CIGs for several hours Friday morning. Confidence in MVFR to IFR CIGs is not very high, but sufficient to add to the TAF with this update. Low clouds will clear Friday mid morning, with winds gradually flipping back to southeast over the High Plains. Gusty west winds are expected near RWL and LAR.

CYS WATCHES/WARNINGS/ADVISORIES

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