


Area Forecast Discussion
Issued by NWS Cheyenne, WY
Issued by NWS Cheyenne, WY
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847 FXUS65 KCYS 161146 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 545 AM MDT Thu Oct 16 2025 .KEY MESSAGES... - A storm system will move through the area today, first bringing showers and thunderstorms, followed by mountain snow and strong winds across the wind prone areas of southeast Wyoming. - A High Wind Warning is in effect for the Elk Mountain and Arlington area along Interstate 80 for late this evening through most of Friday. - A series of clipper systems will impact the region on Saturday and on Monday with another round of strong winds and some rain and snow mix possible down to 6000 feet. && .SHORT TERM /THROUGH FRIDAY NIGHT/... Issued at 310 AM MDT Thu Oct 16 2025 Forecast for the remainder of the week looks on track as the upper level low has moved northeast into northern Utah at this hour, and is expected to lift into central Wyoming by this afternoon. Multiple lines of strong thunderstorms, with a few severe thunderstorms, moved across mainly southeast Wyoming late yesterday evening with a few reports of hail and very heavy rainfall. This activity has since lifted north into the Dakotas. Another cluster of showers with embedded thunder is currently moving north across Carbon and Albany counties at this hour, but is much weaker compared to the convection last night. Areas of fog have been observed east of the Laramie Range and expect this to continue through sunrise until winds begins shifting into the west. Otherwise, kept scattered to numerous showers in the forecast with a few isolated thunderstorms. This activity is expected to slowly translate eastward into the I-80 corridor this morning with fog lifting across southeast Wyoming by 900 AM as the warm front lifts north and the surface cold front moves east across the region through the early afternoon hours. Once the cold front progresses eastward into the plains, surface to 700mb gradients are expected to increase late this afternoon through tonight. Models continue to show increasing low level subsidence along the Laramie Range and the Snowy Range tonight with 700mb winds increasing over 50 knots through Friday morning. With the Canadian on board and in-house wind guidance showing increasing probabilities, decided to upgrade the High Wind Watch to a Warning for the Arlington/Elk Mountain area along I-80 for gusts of 60 to 65 MPH. Models are also showing the surface gradient increasing several hours ahead of the 700mb gradient, so nudged the timing a few hours earlier and started it at 900 pm. Further east, the signal for high winds are not as clear compared to Arlington, so kept the Watch going for now...including portions of Interstate 25. To complicate matters, another high wind event is possible for these same areas Friday night ahead of the progressive clipper diving southeast. Otherwise, high temperatures today and Friday look to be near average for most of the area with highs in the 60s, and slightly below average west of the Laramie Range/I-25 corridor with highs in the upper 40s to mid 50s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Issued at 406 PM MDT Wed Oct 15 2025 As the trough that brought about our short term weather departs, a secondary clipper trough from our northwest will move across the region late Friday into Saturday. While moisture may not be as abundant as it currently is, a few showers and mountain snow showers may be possible. This clipper is bringing in some cooler air, and could even bring snow levels lower than expected with a quick glancing hit of some lower elevation snow, but it would be brief and not expected to accumulate of course. Meanwhile the jet associated with this feature could once again fuel another round of strong winds on Saturday, bringing high wind gusts to our wind prone locations. Sunday a transient ridge will help to clear us out and briefly warm us back into the 60`s to low 70`s, but a deep Pacific trough will bring another round of rain and breezy winds Monday into Tuesday of next week. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 545 AM MDT Thu Oct 16 2025 Pacific storm system will move into southern Wyoming this morning and track northeast through the day. Scattered rain showers and embedded thunder will continue this morning through early afternoon, with improving conditions after 19z. Winds will shift into the west across southeast Wyoming and become gusty this afternoon behind the storm. HAZARDS/WEATHER TRENDS: IFR/LIFR will continue for KCYS and most western Nebraska terminals until 16z to 19z. Conditions are expected to improve to VFR from south (KCYS) to north (KCDR). Showers and thunderstorms may result in brief MVFR VIS and/or CIGS through mid afternoon, especially at KCDR and KRWL. Otherwise, improving conditions through tonight with westerly winds gusting to 30 to 35 knots for the southeast Wyoming terminals. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...High Wind Watch from late tonight through Friday afternoon for WYZ106-107-116-117. High Wind Warning from 9 PM this evening to 3 PM MDT Friday for WYZ110. NE...None. && $$ SHORT TERM...TJT LONG TERM...CG AVIATION...TJT