742 FXUS65 KVEF 110319 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 815 PM PDT Sun Aug 10 2025 .KEY MESSAGES... * Above-normal temperatures continue through the first half of the upcoming week, with Extreme Heat Warnings and Heat Advisories in effect. * Isolated showers and thunderstorms possible mainly along and southeast of Interstate 15, with the best chances Wednesday through Saturday. && .DISCUSSION...through Sunday. Early afternoon satellite loop showed thin cirrus zipping southward through the eastern half of our CWA, a few flat cumulus over Mohave, southern Clark, and eastern San Bernardino counties, and deeper cumulus lurking nearby over the San Bernardino Mountains and Joshua Tree National Park. High resolution models suggest the deeper cumulus will develop into isolated thunderstorms later this afternoon. Otherwise, hot and dry weather expected through Tuesday. The Extreme Heat Warnings and Heat Advisories look good as Major HeatRisk (and splotches of Extreme) expands Monday as high pressure noses in from the Pacific, pushes farther north Tuesday as the high moves overhead, then contracts Wednesday and Thursday as heights fall and attention turns to thunderstorm potential. Multiple times this summer, the NBM has erroneously spread thunderstorm chances westward into our eastern CWA, but this time there seems to be a solid meteorological basis for it. The aforementioned heat wave will create a low level thermal low over the deserts. As upper level low pressure moves into southern Canada midweek, weak troughing hangs back over central California Thursday and Friday - not exactly strong enough to trigger lee-side surface low development, but it could help to maintain or slightly deepen the originally-thermal low. This will set up surface pressure gradients over our area which will turn the low level flow more southerly or even southeasterly, pulling one inch precipitable water as far north as Laughlin beginning Wednesday. This will fuel thunderstorm chances primarily from the Colorado River Valley eastward Wednesday and Thursday, potentially expanding into Lincoln and Clark counties Friday and Saturday before getting pushed back east on Sunday. The GFS also shows very dry air associated with the upper level troughing pushing in from the west, possibly setting up a sharp gradient between moist air to the east and dry air to the west - what has been informally called a desert dryline scenario. These have been associated with severe weather in the past, although the weak upper level flow and lack of dynamic support would not favor it this time. && .AVIATION...For Harry Reid...For the 06Z Forecast Package... Southwest to occasional west winds are expected through much of the overnight period with speeds generally around 8-10 knots. We should also see a period of light and variable winds early Monday morning. Light northeasterly winds should return late Monday morning, and could persist all day until shifting back to southwest around sunset. No operationally significant clouds or weather expected at the terminal, although wildfire smoke could reduce slantwise visibility aloft. Temperature falling below 100F around 04Z this evening and back above 100F from roughly 18Z to 04Z tomorrow, peaking around 108F. For the rest of southern Nevada, northwest Arizona and southeast California...For the 06Z Forecast Package...Wind gusts generally 15 knots or less areawide Monday, although some gusts to around 20 knots are possible near KDAG. Lofted smoke across San Bernardino County and far southern Nevada may reduce slantwise visibility at times. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION...Morgan AVIATION...Gorelow For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter