High Wind in Nevada, April 3, 2023

Area Forecast Discussion
National Weather Service Las Vegas NV
225 AM PDT Mon Apr 3 2023

.SYNOPSIS...Widespread strong winds expected today along with
sharply cooler temperatures as a cold front drops through the
region. A few snow showers will develop during the day across
Lincoln County with light accumulations expected, but otherwise
dry conditions will prevail aside from some transient sprinkles.
Breezy conditions will linger Tuesday with a warm up through the
remainder of the week.

&&

.SHORT TERM...through Tuesday night.

Gusty winds are ongoing this morning across much of the area as a
strong trough digs into northern California before swinging across
the Great Basin later today. Surface winds have responded to the
tightening pressure gradients with wind gusts of 40-50 mph fairly
common along a belt of enhanced southwesterly winds stretching
from Barstow to Las Vegas and into Northwest Arizona.
Additionally, a more focused area of downslope winds has
developed across the Sierra and Owens Valley in response to a the
500mb jet taking aim at the central Sierra, with wind gusts as
high as 80 mph observed on the far west side of Bishop near the
Sierra foothills. As this jet max drops southward through the
early morning, I anticipate these high winds will trend southward
with it, becoming more focused in the southern Owens Valley by
early morning and then ramping up across the Mojave Desert after
daybreak. Given the ongoing wind trends and expectation of
continued Sierra downslope through the morning, upgraded the wind
advisory in the Sierra and Owens Valley to a High Wind Warning.

With the approach of daybreak, winds will continue to ramp up
across the Mojave Desert and latest high resolution guidance
continues to suggest some very strong winds in the Spring
Mountains and far western/southern Las Vegas Valley that will
need to be closely monitored. Strongest downslope winds in this
area will tend to be between 6 am and noon, before a shift to the
northwest occurs with a cold frontal passage. While widespread 60
mph+ wind gusts are unlikely in the Valley itself, I wouldn't be
surprised to see a few gusts to 60 mph or higher in the Summerlin,
Blue Diamond, Southern Highland, and Anthem Hills areas. For now
will keep things as an advisory but will be closely monitoring
trends through the morning.

Otherwise, widespread strong winds expected today with wind gusts
across the Mojave Desert near Barstow and down to Twentynine Palms
still on track to see wind gusts in the 60-70 mph range will
result in widespread blowing dust, localized power outages, and
travel difficulties. Further north, winds will be switching to the
northwest early in the day as the cold front moves through, with
some light shower activity possible along the frontal boundary. A
more focused area of shower activity may develop across Lincoln
County where a few inches of snow is possible above 5000 feet,
mainly north and east of Pioche.

Winds will remain elevated overnight but will gradually ease to
below advisory levels late. Northerly winds may flirt with 40 mph
gusts through the afternoon Tuesday and some parts of southern
Nevada in particular may be worthy of an extension of the wind
advisory, but we'll make that call after we get through the
strongest winds that are expected to occur today. In addition to
the winds, much colder weather will invade the region, with
afternoon highs dropping 10-20 degrees from what was observed
Sunday.

.LONG TERM....Wednesday through Sunday.

Things finally begin to settle down on Wednesday as the trough pulls
away and the flow becomes more zonal. Temperatures will still be
cool, with afternoon highs 10-20 degrees below normal, but winds
will be much lighter. However, the cool temperatures won't last long
as 500mb heights begin to rise, especially towards the end of the
period. WPC Cluster Analysis shows ensemble guidance in great
agreement upon the existence of a Western US ridge by the weekend,
though there remain minor discrepancies in the ridge axis location.
Regardless, the late-week pattern will be very favorable for rapidly
warming conditions. For reference, the NBM gives Las Vegas a 42%
chance of reaching 80 degrees. This probability jumps to 83% on
Sunday. So if you were really looking forward to enjoying typical
Spring-time temperatures, you may want to make the most out of
Friday, as that looks to be the only day with near-normal
temperatures. There's no indication that the warming trend will
cease over the weekend, with the upper-level ridge likely holding
place into next week. In fact, the latest NBM gives Las Vegas a 25%
chance of reaching 90 degrees next Tuesday. In the meantime,
conditions are expected to remain relatively quiet, with light winds
and no precipitation.
&&

.AVIATION...For Harry Reid...Moderate to high impact winds are
expected through much of the TAF period. South winds will gust to
25KT-30KT through the early morning with isolated gusts briefly
increasing to 35KT at times. Winds will become southwest and
increase 14Z-17Z, with high probabilities (70%-80%) for 35KT or
greater winds through the afternoon. There is a low probability
(30%) for wind gusts to 50KT this afternoon, mainly between 15Z and
21Z. Northwest winds will arrive this afternoon between 21Z-00Z.
Wind gusts with the northwest winds will not be as strong as the
southwest winds, but gusts over 30KT are still likely. Gusty
northwest winds around 25-30KT will continue through the night
before slowly diminishing Tuesday morning. Blowing dust may drop
visibilities at times with the strongest winds.

Outside of wind impacts, isolated showers will develop around  the
valley this afternoon between 21Z-03Z. Most likely, these showers
will remain far north and west of the terminals and no rain will
fall at the airport. If a shower did pass over the terminals, rain
would remain light. CIGs between 7000-9000ft are possible this
afternoon with the showers, otherwise CIGs will remain above 10kft
through the period.

For the rest of southern Nevada, northwest Arizona and southeast
California...A cold front will continue to push through the the
region today and tonight. Very strong west winds are expected
through the Mojave Desert with gusts over 50KT possible at KDAG and
KNXP this afternoon. Areas of reduced visibility due to blowing dust
is possible at KDAG today with the strongest winds. Gusty northwest
winds will continue at KBIH with a high probability (70%) for gusts
to at least 35KT. The lower Colorado River Valley will be partial
sheltered with gusts peaking around 30 kts. Scattered rain and snow
showers will be possible along the cold front in Inyo COunty through
Southern Nevada and northwest Arizona. CIGS to around 7000ft and
mountain obscuration will be possible with these showers. Winds will
slowly diminish tonight into Tuesday morning.
&&

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

SHORT TERM...Outler
LONG TERM...Woods
AVIATION...Nickerson

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