430 FXUS65 KCYS 010545 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 1045 PM MST Sat Feb 28 2026 .KEY MESSAGES... - Red Flag Warning remains in effect through 5PM Saturday evening for portions of southeast Wyoming and western Nebraska. - Precipitation chances start increasing Sunday morning and continue throughout most of the upcoming week. - Widespread rain and snow for Tuesday with snow accumulations possible above 6500 feet. && .SHORT TERM /THROUGH TUESDAY/... Issued at 230 PM MST Sat Feb 28 2026 Current observations across southeast Wyoming show winds starting to ease down over the Interstate 25 and Interstate 80 corridors as low level pressure gradients relax. Still seeing a few gusts of 50 to 55 MPH, but expect these to continue to lower through the afternoon and into this evening. Otherwise, a pleasant afternoon today, outside of the gusty winds, with temperatures in the 50s and 60s. Expect similar conditions on Sunday with lower winds compared to what we've seen in the last week. Models show the overall pattern becoming more progressive-zonal with surface winds shifting into south or southeast tonight and Sunday. Moisture was advect into the region at the surface and aloft as the southern branch of the polar jet moves onshore and becomes more active. Expect dewpoints to increase into the 30s by Sunday afternoon. With increasing moisture, low level instability which becomes more noticeable in March, and some jet dynamics, expect shower activity to increase Sunday afternoon across most of southeast Wyoming. Kept POP between 20 to 30 percent for widely scattered rain showers and snow above 9000 feet. Not expecting any Winter Weather headlines for the mountains with 24 hours snow totals through late Sunday evening generally between 3 to 6 inches. Another mild day on Monday before the next round of Pacific storm systems move onshore and into the Intermountain West. Models show the first of these systems moving across the Great Basin region Monday afternoon. Low to midlevel flow will become more southwesterly across the Front Range ahead of the potent trough, with 700mb temperatures climbing above +4c along the Interstate 80 corridor. Expect highs in the upper 50s to mid 60s. There is a chance it may approach 70 degrees below 5000 feet, but cloud cover and a southeasterly wind will likely result in slightly cooler temperatures compared to forecast guidance. Models disagree with precipitation and coverage with the GFS and Canadian model showing mostly dry conditions. However, the ECMWF and most high res guidance show shower activity becoming more widespread late in the afternoon and evening hours as the Pacific trough moves eastward. Increased POP between 30 to 50 percent for most of the area with mostly bands of rain showers expected. With 700mb temperatures and snow levels so high, expect little or no snowfall to accumulate in the mountains during this time period, especially during the afternoon hours. Main forecast concern during the short to medium range is on Tuesday as the previously mentioned potent upper level trough and associated frontal system slides east into the Front Range. Will have to watch this system since this forecast track and temperature profile(s) tend to result in some late-in-the-game surprises for southeast Wyoming (example: about a week ago February 18th-19th). All models show the 500mb flow attempting to close off from the mean flow as the overall pattern becomes more amplified upstream and downstream. 700mb low mean-position is currently near the Wyoming/Colorado border and slows down during the system's evolution late Tuesday. With moisture already in place and good to very good lift (WAA, some low level frontogenesis, 700mb convergence co-located with jet dynamics), increased POP late Monday night into Tuesday with POP up to 80 percent for portions of the area. The big question is snowlevels, with 700mb temperatures hugging -4c to -5c, which roughly translates to snowlevels between 6000 to 6500 feet. The 12z ECMWF and NAM are currently the coldest solution showing 700mb temperatures below -5c with temperatures isothermal between 1000 to 3000 feet AGL, while the Canadian is generally the warmest solution and shows most locations above freezing. Will continue to monitor these trends, but lowered snowlevels slightly down to 6000-6500 feet for now. Thankfully, most of the precipitation occurs during the day so travel hazards should be minimal outside of the mountains. Kept high temperatures in the 40s to low 50s along the Interstate 80 corridor with most of the colder air arriving behind the system. However, if this system trends colder then may need to lower temperatures and snowlevels over southeast Wyoming and western Nebraska. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Issued at 1255 PM MST Sat Feb 28 2026 Early Thursday morning a weak front looks to push through to give us some we precipitation chances throughout the day. Thursday evening into Friday morning the shortwave trough moves in from the west to continue our precipitation chances through the overnight period and into Friday morning. As this system digs its trough further south some colder air (not really Arctic but colder than previous days) follows behind it, so we can expect a dip in our temperatures and increasing chances for beneficial moisture for Southeastern Wyoming and Western Nebraska. This moisture looks to start out as rain and transition into snow for the lower elevations east of I-25. The 700mb jet looks to slightly ramp up as the system pushes eastward. The compressed gradient will strengthen the jet to around 45 to 55 knots over the wind prones Thursday afternoon to Friday morning. Some sporadic gusts may reach high wind criteria but for the most part this looks like a gusty elevated wind event with surface winds between 45-55 MPH for Southeast Wyoming and possibly the Panhandle. Overnight temperatures is where we will mostly feel the colder airmass take place. With those elevated westerly winds temperatures look to remain in the 50's and 60's east of I-25 and in the 40's west of I-25. Overnight temperatures will drop into the mid 20's across the region as our downsloping winds decrease but cloudy skies possibly remain above us. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1040 PM MST Sat Feb 28 2026 Mid to upper level cloud cover will be increasing overnight across the area. RWL and LAR may see some showers in the area, which will have about a 30% chance to produce brief MVFR conditions at RWL during the early morning hours. Nebraska panhandle terminals will be dealing with some LLWS concerns overnight as strong SSW winds are persisting overtop lighter SE winds at the surface. Stronger gusts breaking down to the surface cannot be ruled out. Cloud cover will thin temporarily during the day Sunday, but expect this to increase again in the late afternoon with scattered showers developing. Temperatures should be warm enough to support mainly rain as the precipitation type at ground level, but brief MVFR CIGs will be possible. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...TJT LONG TERM...MM AVIATION...MN