


Area Forecast Discussion
Issued by NWS Cheyenne, WY
Issued by NWS Cheyenne, WY
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105 FXUS65 KCYS 122344 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 544 PM MDT Sat Jul 12 2025 .KEY MESSAGES... - Temperatures will be warming Sunday through Monday, before a potent cold front brings cooler temperatures for Tuesday and Wednesday, with another warming trend for Thursday and Friday. Shower and thunderstorm chances will be greatest for Tuesday and Wednesday. - Elevated fire weather conditions expected late this weekend and early next week. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 224 PM MDT Sat Jul 12 2025 There is an upper level ridge pushing into the Intermountain West placing us in Northwest flow. Looking at water vapor imagery there is some moisture advecting in from the Pacific Northwest that could provide enough moisture for some shower possibly storm development later on this evening. Models are holding onto 1000 joules of CAPE along the I-80 corridor with only a couple hundred joules elsewhere. There is still lingering low stratus along the I-80 corridor keeping temperatures cool and stable. There`s also a very weak shortwave passing through later this evening which looks like the primary forcing for any storm development. However, with this low stratus its uncertain if we will reach convective temperature to spark initiation this afternoon. Also, with the timing of this shortwave it may pass through a little late for storm development as we become more stable with this nocturnal inversion. Slight chance for thunderstorms was kept in case we hit convective temperature with our 1000 joules of CAPE but its more likely that we remain relatively dry today into tonight. Sunday, there could be some fog development as this nocturnal inversion sets up over the low level moisture. The upper level ridge should stabilize our region of the Intermountain West as the subsident flow may inhibit any convection. Sunday afternoon the winds will switch to easterly upslope flow. THis upslope flow may produce some showers in the mountains and morning foggy mess Monday morning for the Summit and Foothills along the mountains if showers do develop. Otherwise temperatures should return to warmer temperatures as the 700mb temperatures reach between 17 to 20 celsius tomorrow. With these warmer temperatures there are some elevated fire concerns mainly for Carbon County as RH values drop into the low teens, however winds gusting over 25 mph will be harder to do under the ridge. && .LONG TERM /MONDAY THROUGH SATURDAY/... Issued at 224 PM MDT Sat Jul 12 2025 The long term will fluctuate between warmth and cooler temperatures thanks to a mid-week system. Monday begins as the warmest day of the period, with highs in the upper 80`s to upper 90`s with some locations across the Nebraska Panhandle eclipsing 100 for the day. A shortwave will be making its way across the region though helping to disrupt the deep high across the southwestern US and with it moisture will return as well. This will start to fuel chances for scattered showers and thunderstorms, but precipitation looks to be mostly sub-severe at this time. That being said, daytime warmth alongside low RH values and breezy winds could bring elevated fire weather concerns for our western and northern zones where fuels have reached critical status. Tuesday a cold front begins to move into the region bringing a more widespread shower and thunderstorm risk alongside cooler temperatures aided by cloud cover. Storms could see a bit more severe risk compared to Monday under more favorable conditions. Wednesday the front should fully pass through the region with highs back down into the 70`s to mid 80`s. Storms could once again initiate thanks to this slow moving feature however, so anticipate another round of potential precipitation. Thursday features temperatures similar to Wednesday, but ridging will start to take back control, and by Friday warming begins anew with 80`s to 90`s once again in the forecast. Precipitation chances linger on both days however as moisture remains and a shortwave on Friday could fuel some stronger activity yet again. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 543 PM MDT Sat Jul 12 2025 A shortwave will move some high clouds into the area this evening and overnight. Clouds will not pose any issues, with conditions remaining VFR through the TAF period. Expect light and variable winds overnight. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MM LONG TERM...CG AVIATION...SF