Area Forecast Discussion
Issued by NWS Las Vegas, NV
Issued by NWS Las Vegas, NV
363 FXUS65 KVEF 171958 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 1258 PM PDT Tue Sep 17 2024 .SYNOPSIS...The next system will drops into the region mid- to- late week, which will reinforce below- average temperatures and return precipitation chances to the southern Great Basin. Conditions dry out once again through the weekend as temperatures rebound back to near average. && .SHORT TERM...Through Friday. Low impact weather will continue tonight and Wednesday morning before the next system drop in from the Pacific Northwest Wednesday afternoon.This potent system will move through the region Wednesday night through Friday, bringing a chance for precipitation across much of the region as it does do. Overall, not much as changed form the previous forecast from this system other than a slight slow down with the onset of precipitation Wednesday afternoon. A few light showers may move into Esmeralda and northern Inyo County Wednesday late afternoon, otherwise the rest of the region will remain dry Wednesday. Overnight Wednesday, the focus of precipitation and impacts will be in Esmeralda and Inyo County where increasing diffluence aloft will provide enough forcing for precipitation to develop. Slightly above normal moisture will be in place over that area, however normal PWATs at this time of the year are around 0.50 inch so there wont be this robust moisture pool for significant precipitation to occur. In fact, moisture looks similar to what was in place on Monday when showers and isolated thunderstorms streamed through Esmeralda County- and no impacts were reported from that round of precipitation. The greatest chance for impacts Wednesday night will be in the Sierra and Whites of Inyo County as model reflectivities hint at precipitation train along the terrain as they stream northward. The upper level low will push eastward Thursday. There continues to be some discrepancy between models to the strength and positioning of the system, with the center of the low Thursday afternoon sitting somewhere in south-central California into western Nevada. This is important as cold core dynamics may come into play near the center of the low. The highest risk for cold core enhancement Thursday afternoon will be in Inyo, Esmeralda, and central Nye counties where a majority of the models show slightly negative LIs and very low end CAPE. Eastern and southern areas like Mohave County, the Colorado River Valley, and much of San Bernardino County should remain dry Thursday as moisture will be low and forcing will be focused further west. Precipitation chances will spread into those areas Thursday night and Friday, however the upper level system should be weakening therefore the risk of precipitation and impacts will be lower. Overall through the entire event, the probability for impactful precipitation amounts is low. There is over a 50% probability for at least some rain (over 0.1 total from Wednesday night through Friday afternoon) in northern Inyo through Esmeralda County with probabilities decreasing as you go south and east. The probability for impactful rainfall totals of 0.5 inch or 1.00 inch over the same the entire event is 10% or less for the entire area. So overall, not expecting widespread significant impacts from this system. Snow levels will remain around 9000ft or higher through the event so any snow will be confined to the very high elevations. Snow accumulation totals will be only a few inches in those areas and winter storm severity levels barley climb into the minor impact levels for the 3 day total. WInds will not be of significant concern with the trajectory of the center`s low and lack of thermal gradient keeping winds below impactful levels. Temperatures Wednesday and Thursday will warm slightly compared to today but will still remain well below normal for this time of the year. .LONG TERM...Saturday through Monday. As the low traverses our area, instability associated with the cold temps aloft should fuel scattered showers and thunderstorms. Saturday looks like the day with the most uncertainty, as most model perturbations show the low center off to our east, but a sizable minority depict a slower movement and leave it lingering over our area for one more day. If the faster movement pans out, Saturday would be dry with several degrees of warming; if the slower solutions verify better, we would expect less warming and one more day of showery weather. As high pressure builds in from the west, Sunday and Monday should be dry and warm, with temperatures close to normal for mid September. && .AVIATION...For Harry Reid...Winds will remain light, less than 10 knots, and will follow typical diurnal directional trends. For the rest of southern Nevada, northwest Arizona and southeast California...Winds at the remaining Las Vegas Valley TAF sites will remain light, less than 10 knots, and will follow typical diurnal directional trends. KBIH will swing around to the south and pick up later this afternoon before shifting to the north in a typical diurnal fashion later this evening. KDAG will favor a westerly direction with 15 to 20 knot wind gusts beginning during the early evening hours and continuing through tomorrow morning. Winds at KEED will remain light and variable. KIFP will favor a southerly to southeasterly direction with sustained speeds o f10 knots or less. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Nickerson LONG TERM...Morgan AVIATION...Stessman For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter