814 FXUS65 KCYS 062338 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 538 PM MDT Wed Oct 6 2021 .SHORT TERM...(This evening through Saturday) Issued at 230 PM MDT Wed Oct 6 2021 Precip chances and potential for strong winds are the forecast challenge with this forecast package this afternoon. Currently...Negatively tilted trough over western Colorado with the upper low looking to be centered over southwest Wyoming this afternoon. Band of coldest cloud tops on IR imagery extends from near Craig Colorado...north northwest over Saratoga....Rawlins up to Worland this afternoon. Surface METARs not reporting much in the way of rain...though Dixon earlier was reporting drizzle. We are getting some light reports from SNOTELS in the Snowy Range with Sand Lake reporting 0.10 inch recently...so will keep PoPs as they are for this afternoon. Further west...a stronger cold front lays along a line from Great Falls Montana...to just west of Pocatello Idaho. For tonight...Mesoscale guidance showing a small chance for showers east of the Laramie Range this evening. Confidence not that great for any showers...but chances are so low...decided to let them stand. Last nice day Thursday before that upstream cold front begins impacting the weather. After a dry start for most areas...look for increasing chances for showers across Carbon County Thursday evening. Concerns for Friday include winds and increasing chances for showers. GFS 700mb winds increase to 30-35kts Friday morning...increasing to 45-50kts Friday evening across Carbon County. Craig to Casper gradients are not all that high...but given the strong 700 to 750mb winds...would expect an increased chance for warning level winds at Arlington and possibly the I-80 Summit. 700mb temperatures fall below freezing behind the front Saturday morning...with rain turning over to snow in the Snowy and Sierra Madre Ranges. Looking at snow accumulations at 2-3 inches. .LONG TERM...(Saturday night through Wednesday) Issued at 230 PM MDT Wed Oct 6 2021 Dry and cooler conditions are expected for the remainder of the weekend and into early next week once the frontal boundary pushes further to the southeast. As a result, daytime temperatures will drop to more seasonable ranges in the mid-60s east of I-25 and colder to the west. Much of the attention for the long term forecast is drawn to the Colorado low setting up across southeastern Colorado Tuesday into Wednesday and pushing to the north/northeast, giving way to a much more active pattern. Currently, the EURO and the GFS have come into better agreement with the EURO now dropping the low further south, showing much better potentials for some upslope flow. At this time, wrap around moisture looks better in the northern quadrants of the CWA, where QPF is around 0.15 and greater. Most areas east of the Laramie Range should start out as rain where 700mb temperatures remain above +0C. But will begin to see an eastward transition to a rain-snow mix into Wednesday. Still a fair amount of uncertainty with this event still being a bit far out to make any impact related forecasts, in addition to the models having a difficult time locking onto a solution for the positioning of the low pressure cell. However, it is looking a bit more promising with each day's model run. Will need to evaluate later model runs to determine specific impacts, if any. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 519 PM MDT Wed Oct 6 2021 VFR conditions expected through the forecast period at all terminals. Some very weak showers are moving across SE WY this evening, and will pass near KLAR and KCYS in the next few hours. This line slowly drifts off to the east overnight, and there could be some isolated showers in the NE panhandle before 12z Thursday. Gusty southeasterly winds in NE will subside by about 04z, turning more westerly behind the weak showers. Thursday afternoon winds are expected to be SW at KRWL, and W to NW to the east. && .FIRE WEATHER... Issued at 230 PM MDT Wed Oct 6 2021 A breezy day out across the Nebraska Panhandle this afternoon as a low pressure system tracks north into southwestern Wyoming. Fortunately...enough low level humidity has filtered into the area to keep critical fire weather concerns at bay. A stronger cold front expected to move into the area from the west during the day Friday...with increasing humidity and chances for wetting rains. Could see very strong winds ahead and just behind this front Friday night into Saturday as it moves through the area. Colder air behind the front will create mountain snow and really decrease chances for critical fire weather conditions through the weekend. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...GCC LONG TERM...MD AVIATION...MN FIRE WEATHER...GCC