968 FXUS65 KCYS 111754 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 1154 AM MDT Sun Sep 11 2022 .SHORT TERM...(Today through Tuesday) Issued at 204 AM MDT Sun Sep 11 2022 Surface high pressure is taking hold of the area despite the lingering low clouds/fog in some spots across the cwa early this morning. A 1024mb surface High is residing over central NE/KS, and the predominant winds that aren't variable are coming from the south-southwest. This weak upslope flow is elongating the thin stretch of low clouds and fog from the CO/WY toward the east- northeast into the WY/NE/CO triple state line region as of 8Z this morning. Areas that have remained under clear skies so far this evening into the early morning have seen temperatures decrease quickly. We have many observations of west of the Laramie Range that are down into the low to upper 30s. Some locations are even in down to the middle 20s along the highest RAWs locations of the Snowy/Sierra Madre Mountain ranges above 8000 feet. Would expect several other locations to begin to creep into the 30s east of the Laramie Range by daybreak. Many will wake up to patchy frost in the Laramie Valley, so have continued the Frost Advisory due to the forecast still being on track. Upper level ridging across the Four Corners region will amplify today, and as it does so, WAA will advance north and east beneath the ridge pattern. Despite the chilly start for many this morning, once we have the daytime heating begin mixing with temperatures at 700mb, we will see a pleasant day for all weather zones across the cwa. Afternoon highs will primarily be in 70s to near 80s degrees for the high plains/lower terrain, with middle 50s to low 60s for the higher terrain. Dry conditions will prevail, with very low minimum RH values west of the Laramie Range from 7-15%. Wind gusts should remain within 10-20mph today, so fire weather concerns will remain low as well. The WAA will continue into the overnight hours as we transition to westerly winds, thus overnight lows will be elevated into the 40s and 50s. Monday and Tuesday will be a return to what we have been familiar with for most of summer...above average temperatures. Monday afternoon highs will quickly surge into the 80s across SE WY, with the NE Panhandle seeing high temperatures near 90 degrees, to potentially the lower 90s. 850mb temperatures across the eastern tier of the NE Panhandle will see +27C to +30C, easily making it another very warm day. Tuesday will see more of the same with above average temperatures expected for the area...highs in the 80s to lower 90s, with slightly cooler readings in the mountains. The only slight change will be that a surface low will develop by late Tuesday afternoon over WY, as an upper level disturbance approaching the region. Increasing clouds over our western zones by the late afternoon will be likely, ahead of precipitation by Tuesday night. Our cool temperatures for the weekend will be a brief memory as the start of next week looks to have another return of summer like conditions. .LONG TERM... (Tuesday night through Saturday) Issued at 200 AM MDT Sat Sep 11 2022 Little to no changes to the long term forecast period. An unsettled pattern is in store due to a series of shortwaves breaking down the high pressure system positioned along the Front Range. Temperatures in southeast Wyoming are forecast to be right around normal for September, whereas the Nebraska panhandle is forecast to be +5 to +10 above normal. This is primarily due to monsoonal surges advecting moisture into areas west of the Laramie Range, then spilling eastward through Wednesday and Thursday afternoons. High pressure builds back in over the weekend, bringing temperatures above average everywhere across southeast Wyoming and the Nebraska panhandle with dry conditions. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) Issued at 1153 AM MDT Sun Sep 11 2022 VFR prevails through the TAF period with SKC conditions likely for all terminals. Winds are expected to remain light. && .FIRE WEATHER... Issued at 204 AM MDT Sun Sep 11 2022 Fire weather concerns will remain low today, despite critical minimum RH values of 7-15% being likely for FWZs west of the Laramie Range. Winds will remain at 10-15mph from the west to west-southwest by the afternoon, but Red flag conditions are not expected for any FWZs today. Overnight RH recovery will be very good, between 55-85% east of the Laramie Range. However, overnight RH recovery will be poor west of the Laramie Range, where maximum RH values will be 25-40% as dry air moves into the area through Monday. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...BW LONG TERM...LK AVIATION...CLH FIRE WEATHER...BW