411 FXUS65 KVEF 062104 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 204 PM PDT Wed Oct 6 2021 .SYNOPSIS...Dry conditions and below average temperatures are expected to persist through Thursday. Another trough will move through the area on Friday bringing gusty winds and a chance for scattered showers with it. Temperatures will continue to cool off over the weekend before dropping well below seasonal averages towards the middle of next week. && .SHORT TERM...Today through Friday. Slightly below average temperatures with dry conditions will continue through tomorrow evening. We will continue to see cloud cover increase through tomorrow afternoon as our upper-level flow becomes more southwesterly, allowing for increased moisture transport which is conducive to cloud development. These clouds will stick around through Friday evening. The 500 mb trough currently positioned off the coast of the Pacific Northwest will continue to dig south before moving inland and into our area on Friday. The lingering moisture combined with southwesterly moisture transport ahead of the trough and the modest lift associated with the trough itself result in increased chances for scattered showers and thunderstorms on Friday. The chance for showers and thunderstorms exist throughout the entire CWA but are more concentrated in the Sierra and Southern Great Basin regions. In addition to the shower and thunderstorm chances in the Sierra, the possibility of snow above 8,000 feet also exists. However, no significant impacts are expected to result from any snow that may fall. Breezy south/southwesterly surface winds will also accompany this trough with gusts around 35 mph possible, with the strongest winds being located north and west of I-15 as well as central Mohave County and the Colorado River Valley. .LONG TERM...Saturday through Wednesday. Precipitation chances will continue through Saturday morning for the Southern Great Basin Desert as the trough moves out of the area, while the remainder of our region should remain dry throughout the weekend. Temperatures will drop further below normal behind the trough. A second upper-level trough is expected to impact the region early next week, pushing temperatures even further below normal, resulting in the possibility of the first sub-freezing temperatures of the season in some portions of our forecast area. As this trough moves into our area Monday afternoon into Tuesday westerly/northwesterly winds will pick up across the CWA with the strongest wind gusts likely north and west of I-15. The Southern Great Basin and the higher elevations of Mohave County will see an increased chance for scattered showers and thunderstorms associated with this second trough. The amount of precipitation we receive will depend on the evolution of the trough. For example, based on Day 5 and 6 Cluster Analyses we would expect more precipitation should the trough dig deeper and progress slightly slower than the ensemble means. && .AVIATION...For McCarran...Winds will hover between 7 and 10 kts this afternoon, initially prevailing from the southeast with directional variability between 130 and 160 before becoming southwest around sunset. Thursday afternoon, gusts will build in from the southwest between 20 and 25 kts, but are expected to fall off after sunset. SCT-BKN aoa 20 kft expected through the TAF period. For the rest of southern Nevada, northwest Arizona, and southeast California...Winds will generally follow diurnal trends today, with wind speeds ranging from 7 to 10 kts. Thursday afternoon, gusty southwest winds will build into the Las Vegas Valley and Colorado River Valley with speeds 20 to 20 kts, but will fall off after sunset. SCT-BKN aoa 20 kft expected through the TAF period. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION...Stessman AVIATION...Varian For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter