textproduct: Cheyenne

KEY MESSAGES

- Near perfect and dry early Autumnal weather will prevail into early next week.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 204 PM MDT Thu Oct 1 2026

Tonight...Primary challenge will be fog duration, areal coverage and cessation. Northwest flow aloft prevails. With return southerly flow at low levels, the low level jet kicks in, especially across the Nebraska Panhandle. Boundary layer progs suggest areas of low clouds and some fog will likely develop along and east of Interstate 25, roughly, and perhaps over the Southern Laramie Range. Thus, agree with the Denver/Boulder NWS office and have added areas of fog along and near the I-25 corridor overnight. Low clouds may be more prevalent as occurred this morning. Where low level mixing will be maximized, decent low level winds will keep minimum temperatures locally higher, such as near Wheatland and over Sioux and Dawes Counties near the Pine Ridge.

Friday...A picture perfect day for outdoor weather enthusiasts due to a minimum of cloud cover, mild southerly winds and 700 mb temperatures near 11 Celsius yielding maximum temperatures from the mid 70s to mid 80s. As a persistence forecast, expect areas of low clouds and some fog to dissipate by late morning, as has occurred this morning. No precipitation expected due to the limited low and mid level moisture, and paucity of cloud cover.

Friday night/Saturday...In this early autumnal progressive synoptic pattern, the next shortwave trough aloft moves into eastern Montana, aiding in the development of a leeside surface trough east of the Rockies from western South Dakota to northeast New Mexico. This decent mixing and atmospheric column warming will produce a relatively mild overnight for early October with relatively mild lows in the lower to mid 50s from Douglas to Wheatland to Scottsbluff.

On Saturday, the shortwave ridge aloft moves to the eastern Dakotas, with a weak cold front, dry due to the lack of enough low and mid level moisture, sweeping south of our forecast area, and bringing in a shot of cooler Canadian origin air, dropping maximum temperatures to the lower 70s to lower 80s, perfect for outdoor weather activities.

Saturday night...In the cooler airmass behind the cold front, expect cooler overnight low temperatures compared to Friday night, although it appears there will be residual cloud cover, perhaps scattered, to limit cooling.

LONG TERM /SUNDAY THROUGH WEDNESDAY/

Issued at 204 PM MDT Thu Oct 1 2026

Mostly benign and warm conditions expected as we move into the long term starting with Sunday, which will actually be our coolest day of the period. We'll see widespread temperatures in the 70's with a few sites possibly peaking around 80, but Monday into Tuesday more widespread upper 70's to 80's will be present under high pressure ridging. This feature may briefly recede and flatten thanks to troughing to the north and allow for a bit more widespread 70's to return by the end of the forecast period, but this will likely be brief as extended models show the ridge building back in beyond the long term. Otherwise with no major features expected to add variability to the forecast, pressure gradients will remain on the weak side with a chance at daily breezy, diurnally driven winds, but nowhere near strong for this region. Elevated to near critical fire weather conditions could be present thanks to the expected dryness and the afternoon breezy winds, and will need to be monitored particularly on Monday when RH's look to be at their lowest. Overall there is high confidence in the forecast, with ensembles showing near unanimous agreement on the above forecast, as a warm start to fall and October continues.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1133 AM MDT Thu Oct 1 2026

VFR conditions expected over the next 24 hours. Easterly to southeasterly winds today will turn more southerly by tomorrow morning into the afternoon, with gusty conditions between 20-30 knots expected all Nebraska sites. One exception will be KRWL which is expected to turn more southwesterly, but will remain similarly gusty. CIGs will be mid to high level at SCT to FEW, though some BKN mid level clouds will be possible near KCYS tomorrow morning.

CYS WATCHES/WARNINGS/ADVISORIES

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