textproduct: Cheyenne

KEY MESSAGES

- Mostly dry conditions and above average temperatures are expected to continue for much of the week ahead.

- The next chance for precipitation and temperatures closer to seasonal averages will be Friday into next weekend.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 258 PM MDT Sat Oct 17 2026

Based on observations, today seems to be overperforming in the dry and warm department. Temperatures this morning were quick to warm up, with many locations warming almost 10 degrees an hour, which was faster than what most models predicted. The rapid warming helped fuel the rapid drying that also occurred, especially in the South Laramie Range and the Arlington area. Relative humidity was already below 15 percent in these areas by 10 AM. With windy conditions also occurring, this prompted the issuance of a Red Flag Warning for the Arlington area where fuels are critical. Fuels are non-critical in the South Laramie Range with visible satellite still showing lingering snow cover. Therefore, held off on a Red Flag for this zone despite the critical conditions. The Red Flag Warning is in effect through 7 PM this evening, at which point winds will begin to weaken and relative humidity should recover. On the opposite end of the spectrum, High Wind Warnings are still in effect but have been underperforming. It has certainly been windy, with gusts up to 50 MPH being observed, but based on surface analysis, the MSLP gradient was not as strong as models suggested in previous runs. Despite not hitting high winds, gusty winds will continue into the overnight hours as MSLP gradients remain elevated.

A weak and subtle cool front will move across the forecast area during the day on Sunday. This will lower temperatures by about 5 to 10 degrees compared to Saturday. Highs will still be a few degrees above average. There will also be a weak shortwave passing to the south of the CWA. This will increase cloud cover across the area during the afternoon hours. Also cannot rule out an isolated shower over the high terrain with the shortwave, however precipitation chances are below 15 percent. Overall, weather conditions will make for a pleasant end to the weekend. Monday will be virtually the same as Sunday, with highs in the 60s. Still some lingering cloud cover over the mountains from the shortwave to the south. Once again, cannot rule out a stray shower in and around the high terrain later in the afternoon.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 258 PM MDT Sat Oct 17 2026

Warm and dry weather is expected to continue through most of next week, though a transition to a more active pattern is possible by the end of the week into next weekend. The synoptic weather pattern for the weak ahead will features a broad ridge over the central US, with another slow moving closed low meandering into the western part of the country. Southwest flow aloft will prevail through most of the week. Temperatures will be well above seasonal averages with 700- mb temperatures around +5 to +8C for much of the week. Look for highs in the mid 60s to mid 70s across the area, which will be about 10-15F above normal. The flow direction will continue to improve mid to upper level moisture through the week. By Thursday afternoon, NAEFS mean precipitable water is actually quite close to climatological maximums. Despite the high moisture content, we don't have much lift to actually translate this into precipitation. Weak heating this late in the season will keep convective instability to a minimum, and synoptic forcing appears unimpressive at this time. Still, we may see some widely scattered high-based showers each afternoon and early evening through the week ahead. Forcing may be strong enough by Thursday to pick up coverage a little as the upper level low to our west inches closer. Fortunately, the moisture advection will mix into the boundary layer periodically, which should keep fire weather concerns down.

The upper level low will make its exit to the east sometime in the Friday through Sunday period. This will present the next chance for notable precipitation, while also dropping temperatures closer to seasonal normals. Most likely, Friday will be another warm day but with increasing chances for rainfall later in the day, with the cool- down waiting until Saturday. Since we are still 6 to 7 days out, precipitation is highly uncertain at this time. NBM PoPs are generally in the 30 to 50% range which seems appropriate at this lead time. While a sizable minority of ensemble members have healthy precipitation totals (0.5" or more), this system appears fairly disorganized so there is also a possibility (30% or so) that it delivers minimal rainfall to our area.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 523 PM MDT Sat Oct 17 2026

VFR conditions are expected for the forecast period. Lingering wind gusts will ease in the next hour or two (except RWL, where it will remain breezy into the evening). Over the High Plains, look for southwest winds to turn more westerly overnight, then northwest Sunday morning, followed by north to northeast by the late morning or early afternoon hours as a weak front passes through the area.

CYS WATCHES/WARNINGS/ADVISORIES

WY...High Wind Warning until 7 PM MDT this evening for WYZ106-110. Red Flag Warning until 7 PM MDT this evening for WYZ427. NE...None.