481 FXUS65 KVEF 040325 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 730 PM PST Fri Dec 3 2021 .SYNOPSIS...Dry and mild weather conditions will persist through the weekend, with high temperatures remaining well above average. A pattern shift will occur early next week, which will result multiple disturbances that will bring in cooler temperatures, breezy conditions, and possibly showers for parts of the region heading into next weekend. && .UPDATE...It's another very peaceful evening across the region with clear skies and light winds area-wide. You wouldn't know it by looking outside, but there is a weak and moisture starved upper low over the lower Colorado River Basin but it will have little influence on our weather tonight or tomorrow owing to the very dry and stable nature of the airmass in place. The current forecast is in good shape, and no updates are necessary tonight. -Outler- && .SHORT TERM...Today through the Weekend. High pressure will continue to dominate the weather pattern through the weekend. This will result in continued light winds, dry conditions, and above normal temperatures to the region. A few more record high temperatures and/or warm lows are possible through Sunday. .LONG TERM...Monday through Friday A pattern shift is expected next week with the area of high pressure that has been sitting over the Southwest US shifting west and opening up the area for weather systems to dive in from the northwest. The first system will slide through Monday and Tuesday. Models remain inconsistent with the exact set up of this shortwave as two waves interact with each other and deepen as they move southwest. However, even with the range of potential setups, no high impact weather is anticipated for the beginning of next week. Probabilities across the spectrum show any precipitation that should fall will be light. The chance for precipitation also continues to trend drier, with the only chance for any light precipitation being through Lincoln and Mohave counties as well as along the Sierra Crest and the Spring Mountains. Any snow will be light and should not amount to more than an inch of accumulation. With the system deepening as it swings through the region, breezy north winds are expected late Monday and Tuesday. Again, winds will remain well below impactful levels in most locations. There is a chance for minor wind impacts down the Colorado River Valley, especially on Tuesday with NBM probabilities showing isolated chances for wind gusts of 40 MPH. This will mainly be a issue for boaters, elsewhere winds will not be a concern. The main thing most people will notice will be the change in temperatures as we drop to near normal highs by Tuesday (and north winds could make it feel even cooler). The more interesting and potentially higher impact system continues to loom at the end of the forecast period Thursday into Friday. The general idea on all the long range models is that a stronger system will develop off the PACNW coast and dive through the region at the end of the work week. However there continues to be a significant difference in model solutions, with one camp insisting that significant moisture will be advected into the region with the track of the system while the other camp is showing a more inland track and therefore less moisture. This is most evident on Atmospheric River plume models and ensembles, with the GFS and GEFS showing a decent AR spreading through the region and ensemble plumes getting into at least a weak AR event for the end of the week...but the ECMWF has a much weaker AR and none of the ensemble plumes even touch weak AR levels. Low confidence in exact impacts and hazards in the forecast for Thursday onward as precipitation chances, winds, and temperatures will all depend on how this system evolves. However, it can be said with some confidence that there is will be a pattern change late next week with temperatures no longer running above normal and at least some precipitation for many locations. && .AVIATION...For McCarran...Light winds less than 8KT following typical diurnal trends are expected through Saturday. Wind direction this evening and again Saturday afternoon may favor the east to northeast, but wind speeds will remain well below 8KT. Occasional FEW-SCT CIGs around 20kft are expected this afternoon will clear out tonight. For the rest of southern Nevada, northwest Arizona and southeast California...Typical wind trends are expected across the region with most locations seeing winds 10KT or less through the TAF period. North winds around 10KT are possible down the Colorado River Valley this afternoon, especially at IFP, though no gusts are expected today. Winds will drop off again tonight. High clouds will clear out this evening, with mostly clear skies expected overnight into Saturday morning. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION/AVIATION...Nickerson For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter