


Area Forecast Discussion
Issued by NWS Cheyenne, WY
Issued by NWS Cheyenne, WY
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939 FXUS65 KCYS 132026 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 226 PM MDT Sun Jul 13 2025 .KEY MESSAGES... - An upper level trough brings a Marginal Risk for severe thunderstorms Monday evening. - A cold front will bring thunderstorms on Tuesday/Wednesday alongside cooler temperatures on Wednesday, but a gradual warming trend will occur thereafter alongside daily shower and thunderstorm chances. && .SHORT TERM /THROUGH MONDAY NIGHT/... Issued at 226 PM MDT Sun Jul 13 2025 Easterly upslope flow look to likely produce a couple brief showers in the mountains south of Laramie this afternoon and evening. There may be a couple bolts of lightning as there will be a couple hundred joules of CAPE to play with but overall rather uneventful. Monday, An upper level trough dives down from the Alberta providence of Canada to give us scattered thunderstorms with some severe chances for the Intermountain west in the evening and early overnight period. Model soundings depict an inverted V sounding indicative of severe winds with hail up to the size of quarters. CAPE values look for modest between 1000 to 1500 joules with the higher values located in the Northern portion of our CWA. Temperatures look to reach into the 90`s with some areas reaching 100 providing a buoyant environment with some mid level moisture advecting into the region. Some models suggest some warm air advection occurring overnight, which would sustain some stratiform rain if that does occur overnight. SPC has a Marginal Risk for Monday afternoon through Tuesday morning with the primary threats being wind and hail. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Issued at 226 PM MDT Sun Jul 13 2025 The long term will remain active as a trough and cold front cool the region off early, but a deep ridge will begin trying to overspread and warm us up, but systems to the north will stave off a stronger and faster warming trend as we move into next weekend. The long term begins Tuesday as a cold front is approaching the region and will slowly pass across through Wednesday morning. This will promote areas of showers and thunderstorms across the CWA with the most likely areas for storms including some stronger activity across Converse/Niobrara Counties in Wyoming, and the Nebraska Panhandle (highest for the northernmost counties here). Any stronger storms will be capable of large hail and damaging winds. On Wednesday with the cold front through the region and stalling along our southern counties and just south into Colorado, cooler temperatures with highs in the 70`s to low 80`s are expected alongside another round of showers and storms. With more moisture moving into the region, the stalled boundary, and another shortwave passing through, even more widespread precipitation is likely with conditions supportive of another day of strong to severe activity. Thursday we begin warming back up though and will continue to do so through the weekend, but the ridge will be slow to build due in part to passing systems to the north. Expect a gradual increase in temperatures with 80`s to 90`s by Saturday alongside daily showers and thunderstorms thanks to the aforementioned passing systems. Enough moisture should be present to help fuel this activity while also keeping our western and northern zones just above critical fire thresholds. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1135 AM MDT Sun Jul 13 2025 VFR conditions expected over the next 24 hours. Skies will be either clear or mid to high level clouds at FEW to SCT primarily for Wyoming terminals. Winds 10-15 knots with some gusts to near 20 knots possible. Winds may begin to increase tomorrow morning for Nebraska terminals right as the forecast period ends. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MM LONG TERM...CG AVIATION...CG