324 FXUS65 KVEF 110929 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 230 AM PDT Thu Oct 11 2018 .SYNOPSIS...A low pressure system dropping south into SoCal will bring a chance for showers to the region today, and again over the weekend along with continued below normal temperatures. Drier conditions are expected next week, but temperatures will remain cool by Mid-October standards. && .SHORT TERM...through Friday Night. A trough digging into the Great Basin this morning will continue to develop southward this afternoon before closing off and pushing offshore of Southern California by Friday morning. This feature will be the primary weather maker for the next several days. Scattered shower activity early this morning continues across mainly northern Mohave county at the moment, though earlier in the night between a quarter and a half an inch of rain was observed from Kingman eastward towards Peach Springs. This activity, aided by favorable jet dynamics, will continue to lift north during the morning hours and begin to lose its upper level support shortly after daybreak. However, broadly difluent flow aloft will remain across the area and encourage additional scattered shower activity during the afternoon and evening hours, especially across southern Nevada and Northwest Arizona. While instability is fairly meager, a stray lightning strike or two isn't out of the question. As the low pushes offshore Friday, drier conditions are expected as the best forcing and divergence aloft will be offshore, however, it will begin to approach the San Diego coast by late Friday night, with shower chances increasing late Friday mainly south of I-40. Temperatures will remain several degrees below normal both today and Friday with the upper low in the vicinity, though decreasing clouds and rising heights Friday should allow for a few degrees of warming over temperatures observed today. .LONG TERM...Saturday through Wednesday. Weekend continues to look cool and unsettled as an upper level low passes to the south. Models are coming into better agreement with the overall setup with moisture increasing on southerly flow ahead of the low. PWATs will increase enough south of I-40 to support precipitation. With sufficient forcing with diffluence aloft, increased chances for showers on Saturday. With cooling temperatures aloft, could be some isolated thunder as well as LIs do go negative, especially in southern Mohave County Saturday afternoon. The chance for precipitation shouldn't hang around long as the low shifts east and dry, anticyclonic flow takes over. Kept Sunday dry even though a few models had some instability showers with the cold core aloft as PWATs drop off quickly. Sunday will be breezy and cooler as the pressure gradient increases behind a cold front sagging south. Increased winds from previous forecast as guidance continues to trend upward. Dont see anything anomalous at this time in the wind or pressure fields compared to climate, so not expecting a major wind event- just some cool northerly breezes. Forecast after the weekend remains uncertain as model solutions differ handling the low to the south. latest GFS runs have trended towards the ECMWF solution, which keeps the upper low over the southwest US as it meanders northward. This would support continued cooler than normal and a mix of sun and clouds over the area for next week. This matched up well with guidance trends, which continued to cool off temperatures. Followed suit, and the only major changes to the forecast made were to knock a few degrees off temperatures through the period. Too much uncertainty in anything else so did not change precipitation chances or cloud cover significantly past Monday. && .AVIATION...For McCarran...Light winds expected through Friday morning. East winds at or less than 8kts develop early this afternoon before turning southeast then south for tonight. VFR clouds should continue, with BKN clouds likely late this afternoon into at least the early overnight, with ceilings between 8-10kft possible. For the rest of southern Nevada, northwest Arizona and southeast California...VFR afternoon clouds will light winds generally less than 10kts today and tonight. A few gusts to 15kts are possible down the Colorado River Valley this afternoon, otherwise no impactful weather expected through tonight. && && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Outler LONG TERM/AVIATION...Wolf For more forecast information...see us on our webpage: http://weather.gov/lasvegas or follow us on Facebook and Twitter