High Wind in California, December 29, 2024

Area Forecast Discussion
National Weather Service Las Vegas NV
1208 PM PST Sun Dec 29 2024

.SYNOPSIS...Strong westerly winds in portions of Inyo, Esmeralda,
and San Bernardino counties will decrease tonight. A persistent
ridge of high pressure will bring above normal temperatures and
quiet weather for most of our forecast area going into the New Year,
except for breezy northerly winds in the Colorado River Valley.
&&

.SHORT TERM...through tonight. Midday satellite loop showed shallow
convective clouds associated with the remnants of the atmospheric
river reaching the Sierra in northern and central Inyo county, and
mostly clear skies over the rest of our CWA. There was one lightning
strike on the west slopes of the Sierra in eastern Fresno county
shortly before sunrise, with no lightning detected since then.
SNOTELs show very little spillover making it to the east side of the
crest thus far. Surface obs have shown winds increasing through the
morning, especially in the higher elevations of the Sierra and the
Spring Mountains. Gusts in the Spring Mountains have been
overachieving thus far, and high resolution models suggest the peak
has not yet arrived, so added a High Wind Warning there. California
Highway Patrol reported a billboard blown onto Highway 395 near the
south edge of the Owens dry lake bed, so the Wind Advisories are
looking good so far. As the day wears on and 700 mb winds increase
over the Mojave Desert, expect surface winds to respond in the
Barstow area, although it may occur a few hours later than
originally thought. Winds in the Las Vegas Valley may also take
longer to work down to the valley floor, which could cause today's
high temperature to be several degrees cooler than expected, or even
occur after sunset if winds take until then to reach the surface. As
the axis of the parent trough moves away to the east tonight, the
surface cold front will make its way south through the southern
Great Basin and into the Mojave Desert. This will allow the strong
westerly winds to shut down from north to south.

.LONG TERM...Monday through Saturday.

Northwesterly flow aloft will hold in place on Monday with subtle
ridging trying to nudge into the Southwest beneath an active storm
track to our north. A small shortwave will drop through the flow on
Tuesday but aside from some high clouds and cooling temperatures, it
is expected to have minimal influence. Thereafter, ridging will
gradually build across the West, with dry conditions and gradually
warming temperatures. Looking beyond, an even stronger ridge is
favored to build across the West over the weekend heading into the
following week, with dry conditions persisting.
&&

.AVIATION...For Harry Reid...Winds are expected to increase out of
the southwest late this afternoon and evening, reaching speeds of
over 10 knots and peak gusts of around 18 knots. There remains some
uncertainty in the timing, possibly starting as early as 23Z or as
late as 01Z. Sustained winds fall to less than 10 knots and shift to
the northwest by 06Z, although there is a 20 percent chance of winds
increasing to over 10 knots between 10Z and 13Z. Winds increase to
over 10 knots from the northeast by 14Z tomorrow morning. Confidence
in sustained wind speeds and gust potential for tomorrow morning and
afternoon remains low at this time. High clouds with bases at or
above 20kft move across the area through the forecast period.

For the rest of southern Nevada, northwest Arizona and southeast
California...Winds increase at most TAF sites this afternoon and
evening. The strongest winds will be at KDAG with westerly gusts in
excess of 30 knots. Northwesterly gusts of around 25 knots are
expected at KBIH this afternoon, shifting to the northeast in the
evening before decreasing later overnight. In the Las Vegas Valley,
southwesterly winds increase this afternoon and evening at KHND with
peak gusts of around 20 knots. At KVGT, moderate northwesterly gusts
are possible early tomorrow morning. Winds in the Colorado River
Valley remain diurnal with speeds at or below 10 knots through
tonight, but become gusty out of the north tomorrow morning at KIFP.
High clouds with bases at or above 20kft move across the area
through the forecast period.
&&

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

SHORT TERM...Morgan
LONG TERM...Outler
AVIATION...Meltzer

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