447 FXUS65 KCYS 252338 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 538 PM MDT Fri Jul 25 2025 .KEY MESSAGES... - Warm and dry weather each day through the weekend. - Critical fire weather conditions in southeast Wyoming possible on both Saturday and Sunday. - Weak storm chances return by the middle of next week. && .SHORT TERM /THROUGH SUNDAY/... Issued at 1255 PM MDT Fri Jul 25 2025 A diffuse ridge of high pressure continues to build over the central and southern Rockies this Friday afternoon. This advancing ridge has shunted surface and mid-level moisture farther east into the high plains, reducing PWAT values over both southeast Wyoming and western Nebraska today. While surface dewpoints in the low-50s still remain in far southeast Wyoming and near 60 dewpoints in southwest Nebraska, forecast soundings indicate a significantly drier moisture profile today. Thus, any convection that does manage to develop should be extremely high based, and limited to only areas in eastern Laramie County Wyoming and the far southwest Nebraska Panhandle today. A gusty shower and perhaps a rumble of thunder can not be completely ruled out as around 20% of HREF ensemble guidance members do fire off a few high-based storms. Expect high temperatures overall to run around 5 degrees warmer than Thursday with a bit more clearing expected overnight. The diffuse ridge of high pressure will move east into the high plains on Saturday as a weak wave passes through the Great Basin and Front Range. This wave of energy will bring an increase to mid-level winds, however moisture profiles will not improve much. Thus, the expectation is for another warm and dry day on Saturday, with increased downslope flow offsetting slightly lower heights aloft as our wave of energy moves through. With deep mixing expected, increased flow will likely make it to the surface especially over Carbon and Albany counties in southeast Wyoming. RH below 15% combined with surface gusts expected to exceed 25 mph has resulted in the issuance of a Fire Weather Watch. A Red Flag Warning will likely be needed if the forecast remains on track. Expect afternoon high temperatures to increase again by around 3-6 degrees on Saturday compared to Friday. High temperatures in the mid to upper-90s are likely for much of the Nebraska panhandle with Chadron likely rising over the 100 degree mark. Low to mid-90s are likely for southeast Wyoming as well, with only a very limited shower threat along the Cheyenne Ridge during the afternoon hours. Forecast confidence remains very high in the short-term with only minor adjustments made to PoP and QPF grids in this forecast package. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Issued at 1255 PM MDT Fri Jul 25 2025 An upper level ridge will pull in warm but dry air into the Intermountain west Sunday to keep us dry but brings along some Fire weather concerns. NAEFS has PWAT values in the 10th and lower percentile for SUnday and 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. 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. This should also result in cooler temperatures for the rest of the week. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 538 PM MDT Fri Jul 25 2025 Storms are slowly dissipating for our Wyoming terminals but VFR conditions should remain throughout this evening and tomorrow morning. Tomorrow afternoon does have an isolated chance for thunderstorms but mainly affecting KCYS and KCDR. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Fire Weather Watch from Saturday afternoon through Saturday evening for WYZ421>423. NE...None. && $$ SHORT TERM...MAC LONG TERM...MM AVIATION...MM