462 FXUS65 KCYS 270510 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 1110 PM MDT Sat Jul 26 2025 .KEY MESSAGES... - Widely scattered showers and thunderstorms will have the potential to produce strong gusty winds this afternoon and evening. - A Red Flag Warning remains in effect until 8PM for portions of southeast Wyoming. Critical fire weather conditions are expected again on Sunday. - A strong cold front will push through the region Tuesday, cooling temperatures significantly and increasing the potential for showers and thunderstorms once again. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 230 PM MDT Sat Jul 26 2025 Southwest flow continues to dominate aloft this afternoon in between west coast troughing and a broad ridge over the central and eastern CONUS. GOES water vapor imagery shows a modest shortwave trough moving over the area at this hour, helping to provide a little boost of lift for shower and thunderstorm activity today. At the surface, numerous weak wind shift boundaries are floating around the area, and these are providing the focus for convective development. Most recently, we are seeing additional development along the diffuse dryline straddling the Nebraska panhandle. With much better low- level moisture here, this is expected to be the main show this afternoon and early evening. The latest mesoanalysis indicates ample instability over the central and southern NE panhandle, with marginal shear (0-6km around 25 to 30 knots). We will need to watch for primarily strong gusty winds, but brief heavy downpours and isolated large hail cannot be ruled out. The showers and storms to the west will bring mainly gusty winds. However, even the western activity may bring a brief downpour and small hail. The shortwave trough axis should pass through the area around 02z, which is expected to limit any shower or thunderstorm activity after that point. Moisture will return to most of the High Plains this evening and overnight, while very dry air remains entrenched to the west. Poor RH recoveries are expected along and west of the Laramie range, keeping fire weather concerns elevated overnight. The dryline will rapidly advance to the east Sunday morning, ushering in a very dry airmass over the entire forecast area. With dry air moving in aloft as well, precipitable water values will fall to under 0.5" for the area, which is near the climatological 10th percentile. Sunday will be largely dry as a result, with very low PoPs for the entire area. && .LONG TERM /MONDAY THROUGH SATURDAY/... Issued at 230 PM MDT Sat Jul 26 2025 An upper level ridge will pull in warm but dry air into the Intermountain west. NAEFS has PWAT values in the 10th and lower percentile Monday to reinforce the fire weather concerns. Winds look also to be a little breezy to put some areas into the critical fire weather category so a Red flag may be warranted especially for area west of the Laramie range. While the RH values look to be under 15 percent across the forecast area the fuels may not be cured enough to warrant a red flag warning. East of the Laramie range, there will be isolated chances for showers and weak thunderstorms mainly in Niobrara county and the Northern panhandle. Tuesday, a cold front looks to push through and provide us with our next precipitation chances in the long term. Looking at the 700mb RH field there looks to be a little bit of moisture associated with this front to be utilized in afternoon convection. Wednesday, an upper level trough moves across the Canadian Providences flattening our upper level ridge even more than Tuesday. The synoptic ascent combined with the continued moisture advection should continue our precipitation chances into Wednesday night. Ensemble guidance has cooler temperatures for the rest of the work week with temperatures in the 70`s and 80`s. However, starting Friday the global ensembles show the area of high pressure currently over the South and southern Midwest to retrograde back to the four corners region of the United States. If this happens then the warm but dry westerly flow will elevate our fire weather concerns for the weekend as storm and shower development will be very limited and RH values may drop below 15 percent. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1109 PM MDT Sat Jul 26 2025 Mostly quiet night tonight with clearing skies over the next few hours. Light winds will be present for most terminals, though KCDR looks to remain gusty through about 10Z this morning. Light winds and mostly clear skies continue through the morning and afternoon hours. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MN LONG TERM...MM AVIATION...AM