textproduct: Cheyenne

KEY MESSAGES

- Near record high temperatures and elevated to 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 SATURDAY/

Issued at 115 AM MDT Fri Jun 5 2026

Some lingering precipitation is noted in Niobrara County and in Colorado/Nebraska bordering our zones, but overall the stronger thunderstorm threat has ended for the day and precip should be exiting the region. With this activity out of the area, we'll now move into a warming and drying trend that will persist through the weekend, though some very isolated precipitation chances may be possible on Saturday. Aloft we'll see a fairly complex and messy setup as high pressure ridging will overtake much of the Front Range and High Plains, but a low over the Central US and a very strong and deep Pacific Trough over the West Coast will keep this ridge from strengthening immediately over the CWA. At the surface, we'll see very dry and warming conditions, with RH values plummeting into the widespread teens by Saturday, while high temperatures today will range in the 80's with a few 90's possible, and on Saturday 90's to some triple digits are expected with these values nearing records for the day.

Meanwhile the enhanced pressure gradient from these aforementioned systems should bring gusty southerly winds, with southwesterly to southeasterly components. The combination of the gusty winds and dry conditions will bring elevated to critical fire weather concerns, particularly on Saturday. The two primary locations for fire weather conditions will be our eastern zones, mostly in Carbon County, and southeastern WY/NE Panhandle. For Carbon County, our last update with partners indicates fuels are not critical, so we will be holding off on any highlights at this time. Our western zones however are another matter, and our last updates indicate that critical fuels remain. We have reached out to make sure that this is still the case due to recent precipitation from the several days of thunderstorms we've seen, but to err on the safe side a Fire Weather Watch was issued for Saturday. This will be updated by Friday night into Saturday morning at the latest, but in any case caution should be exercised moving into this weekend due to the dry and windy conditions expected.

Finally, a weak disturbance riding the periphery of the eastern extent of the West Coast trough will pass across our area on Saturday, and could try it's hardest to produce some form of precipitation during the day, however with how dry conditions will be it's highly unlikely much of this will be able to reach the ground. That being said some instability could produce a few strikes of lightning, creating further fire concerns, and with DCAPE values above 1000 J/kg, the return of gusty showers/virga is expected.

LONG TERM /SATURDAY NIGHT 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 /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 509 AM MDT Fri Jun 5 2026

Primary impacts in the aviation forecast lie in the immediate term, as a band of low clouds moves across the region this morning. Sites KCYS as well as the Nebraska Panhandle could see MVFR to IFR conditions over the next few hours from these clouds. Skies should then become FEW to SKC thereafter with VFR conditions through tomorrow morning. Otherwise periods of breezy winds expected through tomorrow morning, with gusts of 15-25 knots possible all sites.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Fire Weather Watch from Saturday afternoon through Saturday evening for WYZ430>433. NE...Fire Weather Watch from Saturday afternoon through Saturday evening for NEZ434>437.