Lake Wind Advisory 4, NWS Las Vegas, NV

Area Forecast Discussion
National Weather Service Las Vegas NV
214 PM PDT Tue May 14 2019

.SYNOPSIS...A ridge of high pressure will bring above average
temperatures and generally dry conditions through Wednesday. An
abnormally strong Pacific storm moves into the region Thursday,
bringing gusty winds, chances for rain, and sharply cooler
temperatures. After a brief warmup Saturday, another storm system
could affect the region Sunday into Monday.
&&

.DISCUSSION...Drier air has materialized as expected yesterday, with
cumulus clouds limited to the eastern half of the CWA early this
afternoon, except for over the highest terrain of Inyo County.
Deeper clouds over the northeast corner of Mohave County were
producing very light showers, but trace amounts are most likely.
Tomorrow is still expected to be dry areawide, with the main concern
being increasing wind under strengthening southwest flow aloft.
Agree with previous shift that Wind Advisory conditions do not look
likely on Wednesday, but Thursday could be another story. As a
strong negatively tilted shortwave trough axis nears, lee side
surface low development results in a rapidly tightening surface
pressure gradient coincident with upper level support, which should
result in strong southwesterly winds over the Mojave Desert. One
potential fly in the ointment would be widespread clouds and precip,
which would prevent coupling and transportation of the stronger mid
level winds to the surface. Looks like that will be more of a factor
in the morning, with rapid clearing possible during the day, which
could lead to a sharp increase in wind speeds. Will keep an eye on
this. Thursday will also be the peak time for snow in the higher
elevations of the Sierra. In collaboration with WFO HNX, upgraded
the Winter Storm Watch to a Warning valid from midnight Wednesday
night through 6 AM Friday morning. Still looks like a foot or even a
bit more above 9000 feet, with significant accumulations down as low
as 6000 feet. Winds will decrease Thursday night as the main trough
axis arrives, and precip chances will be limited to the southern
Great Basin (nearest the low center) on Friday before finally ending
Friday night. Progressive shortwave ridging will bring a brief break
and warmup on Saturday before the next storm rolls in Sunday and
Monday. A little early to pin down details on this one yet.
&&

.AVIATION...For McCarran...Southwest winds will prevail for the
remainder of the afternoon at speeds of 10-15 knots gusting 20-25
knots through 02z-04z. Gusts will become more intermittent this
evening as wind speeds come down to 8-10 knots. Southeast winds
between 150-180 degrees will be possible again tomorrow morning
between 14z-20z but speeds should remain at 10 knots or less. By
20z, winds will have shifted to the southwest once again and
increased to 15-20 knots gusting 25-30 knots. Scattered afternoon
mid-clouds at 10k-12k feet and increasing high clouds throughout the
period can be expected.

For the rest of southern Nevada, northwest Arizona and southeast
California...Southwest winds will remain breezy this afternoon
between 10-20 knots gusting 20-30 knots before winds decrease this
evening and overnight. The exception will be the western Mojave
Desert with these winds speeds holding on through late tonight.
Slightly stronger winds are expected for Wednesday; increasing late
morning through afternoon to speeds of 15-25 knots gusting up to
around 35 knots. FEW-SCT mid-cloud deck between 10k-12k feet will be
present this afternoon with high clouds increasing from west to east
throughout the period.
&&

.SPOTTER INFORMATION STATEMENT...A late-season system will bring
gusty winds, cooler temperatures, mountain snow, and shower and
thunderstorm chances to the region on Thursday. Spotters are
encouraged to report any significant weather or impacts according to
standard operating procedures.
&&

DISCUSSION...Morgan
AVIATION.....Guillet

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