873
FXUS65 KVEF 022108
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
208 PM PDT Thu May 2 2024

.SYNOPSIS...Dry conditions with seasonably warm temperatures are
expected through Friday. Over the weekend, a strong system will
approach the region, bringing widespread strong winds on Saturday
with cooler temperatures, light precipitation across the southern
Great Basin, and continued gusty winds along the Interstate 15
corridor for Sunday. Improving conditions are expected early next
week with temperatures slowly moderating.
&&


.SHORT TERM...Today and Friday.

Dry and seasonably warm conditions will continue through Friday as a
weak trough in the Intermountain West moves east. Lingering north-
south pressure gradients will foster continued north breezes down
the Colorado River Valley today with wave heights of 1 to 2 feet
expected on Lake Havasu. Elsewhere, expect mostly clear skies and
southwest afternoon breezes today and Friday.


.LONG TERM...Saturday through next Wednesday.

At the start of the period, a strong closed low is forecast to move
into the west coast. Ahead of the low, notable surface pressure
falls will occur over the Great Basin, driving strong south-
southwest winds across the entire forecast area. Latest NBM guidance
paints all but southern San Bernardino and southern Mohave counties
with 50-90% chances of impactful winds on Saturday. Chances of 55+
mph winds have increased in area, with the highest chances existing
across western San Bernardino, Inyo, Esmeralda, southern Nye,
Lincoln, and northern Clark counties. Winds remain strong into
Sunday afternoon as the low traverses the Great Basin, with a
northwesterly wind shift pushing northwest-to-southeast throughout
the day.

As such, High Wind Watches have been hoisted across the region
Saturday morning through late Saturday night. However, for locations
along the Interstate 15 corridor including Las Vegas, Pahrump,
Barstow, Baker, Overton, Mesquite, and Laughlin, due to elevated
winds persisting overnight into Sunday, the High Wind Watch will
continue for these areas through late Sunday afternoon.

The other aspect of this system we`ll have to monitor is
precipitation potential. Ensemble guidance depicts a tongue of 150-
200% of normal PWATs feeding into our area ahead of the trough axis.
While not overly impressive moisture values when you consider normal
for early May is about 0.37", it`ll be enough to spur 30-60% PoPs
across the southern Great Basin. High snow levels should prohibit
any wintry impacts below 8000 ft, though locations above 8000 ft
could see beneficial snow on the peaks. The NBM the percentile
(reasonable worst-case scenario) keeps QPF values generally below
0.50", except on the Sierra crest where it gets up to 0.90". As
such, rainfall impacts should be minimal (if any) in these
locations. The one caveat to this will be the development of
convection. The anomalous closed low will feature very cold air
aloft, with deterministic guidance showing 500mb temps less than
- 20C. If the low`s center can pass through during peak heating on
Sunday, we could see a thunderstorms in parts of the area, which
will result in locally higher rainfall. Currently, best chances of
thunder remain over Lincoln County and the Arizona Strip with
around 15% chance.

As the weekend system pulls away on Monday, winds weaken, PoPs wane,
and temperatures quickly rebound. By mid-week, highs are forecast to
be within a few degrees of normal, far from the 10-15 degrees below
normal forecast for Sunday. Afternoon breezes will persist, but not
of the magnitude nor impact of this weekend`s winds.
&&


.AVIATION...For Harry Reid...Light easterly winds of less than 8kts
this afternoon will come around to the southwest by late afternoon,
with speeds increasing to 10-12kts. Winds will decrease after
sunset and remain light into Friday morning. Similar conditions
are expected tomorrow, with northeast winds in the late morning
and early afternoon turning to the southwest by late afternoon.
Winds will increase by Saturday afternoon, with southwest gusts
over 40kts possible by Saturday evening. VFR conditions will
prevail across the valley through Friday.

For the rest of southern Nevada, northwest Arizona and southeast
California...Surface winds at KBIH will favor a northerly direction
through the forecast period, with speeds remaining less than 12kts.
Westerly winds to 15kts are expected at KDAG through the TAF period,
while winds in the lower CRV will be lighter and favor typical
diurnal trends. Winds in the Las Vegas Valley will also favor
typical diurnal trends through Friday, with speeds generally 12kts
or less. All areas will see gusty southwest winds develop by
Saturday afternoon, with gusts over 40kts possible by Saturday
evening. VFR conditions will prevail at all TAF sites through
Friday.
&&


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

&&

$$

SHORT TERM...Varian
LONG TERM...Woods/Varian
AVIATION...Planz

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