High Wind in California, May 19 to 20, 2022

Area Forecast Discussion
National Weather Service Las Vegas NV
Issued by National Weather Service Flagstaff AZ
253 PM PDT Thu May 19 2022

.SYNOPSIS...An incoming system will bring gusty south to west
winds and fire weather concerns to the area through tonight. Winds
stay elevated Friday morning but will gradually diminish throughout
the day with temperatures significantly cooler Friday and Saturday.
More seasonal temperatures Sunday and Monday. A ridge is expected to
build over the region later next week which will allow for the
return of above average temperatures.
&&

.DISCUSSION...A very warm day is underway across the area this
afternoon as Las Vegas Airport has officially hit 100 degrees for
the first time this season. These temperatures are about 10
degrees above average, but still a few degrees shy of record
temperatures for today. This is in response to a mild west-
southwest flow aloft ahead of a deepening trough to the north.

A trough of low pressure over the Pacific Northwest will deepen
while moving south into the Great Basin tonight. Winds will
continue to strengthen ahead of a cold front that will move into
southern Nevada late tonight/early Friday morning. Gusty west to
southwest winds have developed this afternoon ranging from 30 to
40 mph. Areas of critical fire weather are being observed in
response to the gusty winds and low humidity, and Red Flag
Warnings remain in effect for southern Nevada and northwestern
Arizona through this evening. Gusty winds will continue ahead of
the cold front this evening, especially across the Eastern
Sierras, Owens Valley and western Mohave Desert where a Wind
Advisory remains in effect through daybreak Friday. Gusts in the
advisory area will approach 50 mph. Elsewhere, localized gusts to
45 mph will be possible tonight over the higher mountainous
terrain of northern Nevada and northwestern Arizona.

The aforementioned front will progress southward on Friday
resulting in winds shifting to the north through the day. Winds
will remain breezy, especially over higher terrain and down
through the Colorado River Valley. The continued gusty north winds
and low humidity will lead to continued critical fire weather
along the Colorado River and Red Flag Warnings remain in effect
through Friday afternoon. In addition, temperatures will see a
significant drop on Friday - down a good 15 degrees over today's
highs.

A period of generally lighter winds will return over the weekend.
Temperatures will remain cool on Saturday but begin to rebound
closer to average by Sunday afternoon. A dry northerly flow will
keep tranquil weather over the area through early next week. Long
range indications point toward a strong ridge building into the
southwest by the middle of next week which will likely lead to
significantly warmer temperatures.
&&

.FIRE WEATHER...Red Flag Warnings remain in effect across southern
Nevada and northwest Arizona through this evening with critical to
near critical conditions expected again on Friday. Gusty west to
southwest winds will peak this afternoon through this evening.
Minimum humidity values will range from 5-15 percent. Humidity
values recover to 15-25 percent overnight as a cold front crosses
southern Nevada. Gusty north winds will continue into Friday morning
before gradually diminishing through the afternoon.
&&

.AVIATION...For Harry Reid...Gusty southwest winds with gusts around
25 knots through much of tonight. A cold front will move through
southern Nevada overnight with a wind shift to the north Friday
morning. Low confidence on the exact timing and direction of the
northerly wind shift, which will depend on the strength of the
frontal winds. However, best timing for the northerly shift will be
between 14-16Z. Southwest winds will slightly decrease after 09Z
before increasing from the north to northeast around 14Z. Breezy
northeast winds will continue into Friday afternoon before starting
to drop off into Friday evening. Some FEW to SCT aoa 25 Kft will be
possible through the forecast period.

For the rest of southern Nevada, northwest Arizona and southeast
California...West to southwest winds around 15 to 25 knots and gusts
up to 35 knots will be possible at all terminals. Wind swill start
to drop off a bit after 02Z and may further decrease just ahead of a
cold front. Winds will increase and become breezy northerly winds
Friday morning through Friday afternoon. Some FEW to SCT aoa 25 Kft
will be possible through the forecast period.
&&

For the rest of southern Nevada, northwest Arizona and southeast
California...
&&

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

DISCUSSION...MCT
AVIATION/FIRE Weather...Meola

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