941
FXUS65 KVEF 300328
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
828 PM PDT Mon Apr 29 2024

.SYNOPSIS...Warming temperatures, mostly clear skies, and afternoon
breezes expected today and Tuesday before a weather system briefly
moderates temperatures and returns gusty north-northwest winds to
the forecast area. Temperatures will warm once again through the
remainder of the work week before another weather system approaches
late weekend into early next week.
&&

.UPDATE...Most areas are seeing southwest breezes this evening
except across the Western Mojave Desert where gusts 25-35 mph
continue near Barstow. Winds are forecast to decrease everywhere
overnight becoming light by daybreak Tuesday morning. Low
temperatures in the morning are forecast to be similar to what
they were this morning. The forecast looks on track so no updates
are needed this evening.

&&

.PREV DISCUSSION...1229 PM PDT Mon Apr 29 2024...

.SHORT TERM...Today through Wednesday.

With a trough to our east and a Pacific ridge to our west, the
Desert Southwest rests underneath a dry northwesterly flow aloft.
This flow is conducive for shortwave passages, which will lend to
breezy afternoons through Tuesday, with afternoon gusts between 20
and 25 mph expected. Additionally, increasing heights over the
region will result in increasing temperatures through Tuesday, with
temperatures ranging 5-7 degrees above seasonal averages Tuesday
afternoon. Conditions will continue to dry out, with single-digit
relative humidity values expected for nearly the entire forecast
area by Wednesday afternoon. The exception to this will be
elevations above 6500 ft, though even those elevations will drop
into the teens.

An open wave trough will pass through the southeastern Great Basin
on Wednesday, which will increase north-northwest winds across
southern Nevada, southeastern California, and northwestern Arizona.
Winds should remain below advisory levels, though isolated gusts to
40 mph cannot be ruled out in the higher terrain, particularly in
northern Inyo, Esmeralda, and southern Nye counties. This system
will be dry, so no chance of precipitation expected.

.LONG TERM...Thursday through next Monday.

As the aforementioned trough pushes eastward out of our forecast
area, residual tight pressure gradients will result in enhanced
winds along the Colorado River Valley. Coupled with topographic
enhancement, gusty winds could result in hazardous boating
conditions on Lake Mohave. Will continue to assess the need for any
wind-related lake headlines over the next few shifts.

Otherwise, warm and dry conditions will continue with single-digit
afternoon relative humidities for the entire forecast area through
the rest of the work week into the weekend.

Uncertainty continues in the long term, though trends are becoming
more clear. The GFS ensemble means indicate a deep closed low will
dig into the Desert Southwest from the Pacific Northwest late this
weekend, bringing with it a drop in temperatures, a return of gusty
winds, and an increased chance of precipitation across the forecast
area. This is also seen in the GFS IVT (Integrated Water Vapor
Transport) plume, with a respectable water vapor feature stretched
across southeastern California into southern Nevada, northwestern
Arizona, and southwestern Utah. On the other hand, the ECMWF ensemble
mean indicates that this closed low will remain north of our area
and will traverse across the Intermountain West. As you could
imagine, this solution is much drier, though temperatures would
still moderate and wind speeds would still increase across the area.
Details will continue to become clear as we progress through the
work week.
&&

.AVIATION...For Harry Reid...Southwest winds with gusts between 20kts
and 25kts will continue through sunset. Winds are then expected to
quickly diminish this evening, falling below 10kts by 04Z and then
becoming light and variable overnight. A period of southeast winds
possible tomorrow morning before winds return to the southwest by
the afternoon; although, gusts should be a bit lower than today,
topping out at around 20kts. Mainly clear skies are likely through
the TAF period.

For the rest of southern Nevada, northwest Arizona and southeast
California...Gusty southwest to west winds are expected across the
region through this afternoon before decreasing after sunset. Most
regional TAF sites should see winds fall below 10kts overnight,
except KDAG, where winds to 15kts will continue. All areas will
see gusty south-to-southwest winds redevelop by late tomorrow
morning. Other than a few high clouds AOA 20kft AGL near KBIH and
the Sierra during the afternoon hours today and Tuesday, mainly
clear skies are expected areawide through the TAF period.
&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.

&&

$$

UPDATE...Salmen

DISCUSSION...Varian
AVIATION...Planz

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