944 FXUS65 KCYS 082345 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 545 PM MDT Sun Jun 8 2025 .KEY MESSAGES... - The back door cold front early this morning may bring isolated to scattered showers and thunderstorms this evening in the higher elevations mostly near the CO border. - Much warmer next week with highs becoming 5-10 degrees above normal with a daily low-end risk of passing showers or thunderstorms each evening. && .SHORT TERM /THROUGH MONDAY/... Issued at 211 PM MDT Sun Jun 8 2025 An influx of low level moisture mixed with pretty stable conditions led to a formation of fog this morning to early afternoon in the Summit and Foothills along I80. A dense fog advisory was issued as the formation of fog dropped visibility down to 1/16th of a mile in some locations. From Rawlins to Laramie is generally clear leading to some possible development of storms in the mountains. Given the model CAPE values between 200-500 j/kg with virtually no shear, these storms are going to be mostly rain makers with some thunder and lightning possible. Hi-Res guidance doesn`t have these lasting very long if they do develop. Model consensus looks to have the best timing between 23 and 02z with the general storm motion being southeast for a quick pass through of Carbon county. Winds are also going to be a little breezy this evening as an upper level low pushes east into the Northern Plains/Midwest against our soon to be upper level ridge pushing in from the west. These winds should die off by tomorrow morning when the ridge would be more over us. Monday, Looks pretty dry as the upper level ridge slowly starts to move east into the Intermountain West. Winds will be a typical Wyoming breezy type of day but calmer than Sunday evening. Some of the dry smokey air will filter in dropping dewpoints into the low 20`s and upper teens, with the driest part being in Northwest Carbon County. The smoke concentration doesn`t look to be that bad as current sensors have it slightly above green (healthy). So members of the sensitive population may notice it some as the smoke plume is slightly visible on satellite but doesn`t seem like a lot of it is filtering down. Skies should also be relatively clear under the ridge as the subsident flow should clear out most clouds. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Issued at 211 PM MDT Sun Jun 8 2025 The long term will be dominated by warmer than average temperatures thanks to high pressure ridging controlling the region for the duration of the period. Expect highs in the 80`s for most of the CWA, with temperatures at their lowest on Wednesday and Thursday as the ridge flattens and evening showers and thunderstorms return thanks to passing systems, alongside a bump in cloud cover. But by Friday and into next weekend, the ridge should begin rebuilding which will allow temperatures to rise to their warmest of the week. Some of the ensemble members expect the risk of precipitation to remain during the peak heating hours, but other guidance suggests any disturbances by this time may not have enough moisture and forcing to work with to produce activity. Expect summer warmth to hit in full force this week with no signs of slowing into the extended forecast period. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 545 PM MDT Sun Jun 8 2025 Upper level disturbance will push southeast of the area tonight with high pressure aloft building over the Front Range for Monday. Any remnant showers will dissipate by 02z. HAZARDS/WEATHER TRENDS: VFR conditions will prevail this evening and tonight with low clouds dissipating and shower activity already pushing south into northern Colorado at this hour. Expect clearing skies and relatively light winds. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MM LONG TERM...CG AVIATION...TJT