Boulder City, NV Weather

Key Messages

* Gusty north winds today with lingering shower and storm chances in northwestern Arizona.

* Quiet and seasonable conditions through at least Wednesday, with signs of a more active pattern returning late in the week.

Discussion

through Halloween.

Water vapor imagery shows a trough overhead with a vort max over southern CA in the process of pinching off into a closed low. Behind the shortwave, gusty north winds are currently pushing through the southern Great Basin and into the northern Mojave Desert. These will continue advance southward, encompassing most of the CWA by sunrise. Strongest winds anticipated in Death Valley and the southern Owens Valley where gusts of 40-50 mph are possible through the morning hours. Elsewhere, expecting gusts generally 20-35 mph, weakening during the 2nd half of the day. The formation of the closed low will cause the system to slowly exit the region, lingering over northwestern AZ this afternoon. The cold air aloft, residual moisture, and daytime heating should drive isolated to scattered showers and maybe even a few storms over eastern Mohave County (20- 40%), with lower chances (10-20%) over southeastern NV and the Colorado River Valley. Can't completely rule out an isolated instance of flash flooding in eastern Mohave County, but odds are 5% at best.

Our low finally exits on Sunday, leaving us in a zonal pattern for a few days before transitioning to southwesterly flow later in the week. From Sunday - Thursday, the forecast calls for seasonable temperatures, light breezes, and dry conditions. Late in the week, ensemble guidance shows an energized subtropical jet trying to push moisture into the southwestern US. Cluster analysis shows several variations of offshore troughing during this time, so there remains a fair amount of uncertainty, but there appears to be a good signal for the existence of an offshore trough and southwesterly flow over us. Should this come to fruition, we should see an increase in southwest winds and low to moderate (10-50%) precipitation chances around Halloween weekend.

Aviation

For Harry Reid...For the 06Z Forecast Package...Light northwest will persist a few more hours. A push of stronger northwest winds are expected tonight, likely after 09Z. Gusts up to 25KT are expected with these stronger winds with the push of winds, especially at onset. Gusty northwest will continue through Saturday morning into the afternoon, then will slowly diminishing 21Z. Gusts should end by 00Z. Northwest will continue into Saturday evening but will remain at 10-15KT for the first part of the night, then lighter winds will arrive by 06Z. VFR mostly clear skies will persist through the TAF period.

For the rest of southern Nevada, northwest Arizona and southeast California...For the 06Z Forecast Package...Expect an increase in winds overnight at most locations as a cold front pushes through the region. Gusts 25-35KT are expected behind the front. Gusty north to northwest winds last into the first half of the day Saturday, then likely begin diminishing late afternoon and evening. Mostly clear skies last through the TAF period. Other a few isolated showers in Mohave County Saturday night, it will be dry across the region.

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