476 FXUS65 KCYS 221124 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 524 AM MDT Mon Oct 22 2018 .SHORT TERM...(Today through Tuesday night) Issued at 315 AM MDT Mon Oct 22 2018 Another clear and quiet morning across southeast Wyoming and western Nebraska with some high clouds starting to push into the region ahead of the broad upper level trough/low moving across the Great Basin today. IR satellite loop shows two distinct shortwaves embedded in the broad disturbance aloft. One shortwave is moving northward across the northern Great Basin and is not expected to influence the weather across southeast Wyoming, the southern shortwave is currently moving across the southern Great Basin and Arizona, with thunderstorms continuing across Utah and Arizona early this morning. This shortwave will influence the weather over the next few days, although impacts should be minimal at best. For today and tonight, do not expect much change to the weather compared to the last few days with the exception of increased cloud cover and slightly cooler temperatures. For Tuesday, high res models show widely scattered showers moving northward into Carbon and Albany counties early in the morning, with activity slowly spreading eastward through the day. However, this is a low confidence forecast since the coverage is still greatly in question. The GFS has trended towards the ECMWF solution showing the main shortwave, and associated jet energy, remaining to the south of the area, due to the weaker ridging across the Great Plains. Kept POP mainly between 20 to 40 percent through Tuesday, highest in the mountains. This forecast may even be overdone based on the recent NAM and short range ensembles. Expect the highest chance of rainfall to be Tuesday night and into Wednesday as the shortwave lifts northeast into Kansas and Oklahoma. Outside of some high elevation light snow, impacts will be very limited. .LONG TERM...(Wednesday through Sunday) Issued at 330 AM MDT Mon Oct 22 2018 Models now in better agreement through the remainder of the week, showing the broad Pacific trough/disturbance moving into the central plains late Wednesday with any shower activity across western Nebraska coming to an end late in the afternoon. Otherwise, models continue to indicate a return to northwest flow aloft with seasonably cool temperatures. Winds may become more of a concern for southeast Wyoming late Thursday through Saturday as low to midlevel gradients increase ahead of a series of progressive upper level shortwaves moving southeast out of southern Canada. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) Issued at 519 AM MDT Mon Oct 22 2018 VFR conditions are expected at all terminals this morning and afternoon. An approaching weather system will begin to affect the area from the west this evening and overnight. Mid level CIGS will develop in the later afternoon dropping overnight. MVFR to IFR conditions will be possible as low CIGS and areas of fog are likely to develop in the easterly upslope flow overnight through early Tuesday. && .FIRE WEATHER... Issued at 226 AM MDT Mon Oct 22 2018 No Fire Weather concerns this week with higher humidities expected beginning today as surface winds shift into the east, and eventually, southeast. Isolated to widely scattered showers with a small chance of thunder is expected Tuesday and Wednesday over southeast Wyoming, with a better chance of rainfall further east across western Nebraska. Temperatures will lower slightly through mid week. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...TJT LONG TERM...TJT AVIATION...AL FIRE WEATHER...TJT |