799 FXUS65 KVEF 071650 AFDVEFArea Forecast Discussion National Weather Service Las Vegas NV 950 AM PDT Sun Sep 7 2025
.KEY MESSAGES...
* Monsoonal moisture will support one more round of isolated shower and thunderstorm activity this afternoon.
* A drying trend is expected the first half of the week as flow becomes more westerly. Relatively cooler temperatures will also overspread the region by mid week.
&&
.DISCUSSION...Through next Saturday.
Although the downward trend in moisture continues today, there is still enough moisture and instability for isolated thunderstorms this afternoon. CAMs show potential over Mohave County, the Colorado River Valley, and eastern San Bernardino County. Forecast soundings still indicate pockets of deep moisture and PWATs in the 1 to 1.5 inch range in these areas, which means that heavy downpours and flash flooding still can`t be ruled out. Soundings also show 1200 to 1500 J/kg DCAPE, meaning gusty outflow winds are also within the realm of possibility. Convection should favor high terrain where forcing is the greatest and activity will end after sunset with a loss of surface heating.
A large upper trough will track east into the California coast early this week, pushing any remaining moisture out of the forecast area. With lower heights, temperatures become 5-10 degrees below seasonal normals by midweek. This means highs in the low 90s to upper 80s for Las Vegas. The drier air will also bring more relief overnight with cool morning lows, including temperatures in the low 70s in Las Vegas by midweek. Temperatures may start to increase again towards next weekend as the low exits east and heights aloft begin to rise.
&&
.AVIATION...For Harry Reid...For the 18Z Forecast Package...Light and variable winds will shift to the south and southwest early this afternoon, increasing to around 10-12KT with at least intermittent gusts to around 20KT through early evening. After sunset, gusts diminish, though southwesterly winds will remain around 10KT overnight and become gusty once again toward the end of the period. VFR conditions will prevail with minimal thunderstorm activity and temperatures remaining under 100 degrees.
For the rest of southern Nevada, northwest Arizona and southeast California...For the 18Z Forecast Package...Conditions will be far less unsettled today, with isolated thunderstorms generally confined to the higher terrain of northwestern Arizona and the southern Mojave Desert this afternoon. Light winds this morning will shift to the south and southwest this afternoon, with gusts to 20-25KT common, though will be somewhat lighter in the Owens and Lower Colorado River Valleys, and favor more of a westerly direction INVOF KDAG. Gusts will diminish this evening, with VFR conditions prevailing.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures.
&&
$$
DISCUSSION...Meltzer AVIATION...Gorelow
For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter
NWS VEF Office Area Forecast Discussion