583 
FXUS65 KVEF 060230
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
730 PM PDT Sat Nov 5 2022

.SYNOPSIS...A few more degrees of warming are in store for most 
locations on Sunday but clouds and some precipitation will begin to 
work their way into the eastern Sierra. Precipitation is expected 
across much of the southern Great Basin and Mojave Desert Monday 
night through Tuesday night. Also expect periods of gusty winds 
along with unseasonably cool temperatures.
&&


.UPDATE...Impressive jet stream of 150+ knots will stay aligned west 
to east along and just north of Nevada tonight. With the jet not 
sagging south moisture feeding inland will keep any precipitation 
along and north of Highway 50 in central Nevada. Also, could see 
some light precipitation breakout along the southern Sierra crest 
overnight. Elsewhere, skies will stay party to mostly cloudy.

Tomorrow. Winds aloft will back, more from the west/southwest as 
trough begins to deepen along the west coast. Any precipitation 
looks to get intercepted by the southern Sierra with again only 
light amounts spilling over into Inyo County. Leeside pressure falls 
across Nevada will allow surface pressure gradients to tighten 
tomorrow afternoon leading to stronger breezes with some gusts up to 
30 mph expected. This well covered in current forecast with no 
update this evening.  
&&

.SHORT TERM...today through Sunday.

A strong upper level low is currently organizing off of the British 
Columbia coast. The low will slowly drop south over the next several 
days but in the meantime mainly zonal flow will provide a relatively 
tranquil weekend to the area. Temperatures will continue to moderate 
the next couple of days and be relatively close to their seasonal 
normals on Sunday. The only exception will be in the eastern Sierra 
where some moisture will begin to spill across the Sierra from the 
approaching atmospheric river and will provide an increase in clouds 
and some precipitation. Snow levels with this initial round of 
lighter precipitation will be in the 8000-9000 foot elevation.

.LONG TERM...Sunday night through Saturday.

As the strong upper level low drops down the west coast deeper 
moisture from the AR and a better trajectory will enable a much more 
substantial push of moisture to begin to impinge on the southern 
portion of the Sierra Mountains and across into the eastern Sierra 
and Owens Valley Sunday night. This will bring what looks to be the 
first major snowfall event for the Sierra this season and a Winter 
Storm Warning remains in effect from 10 PM PST Sunday until 10 AM 
PST Wednesday. 

Continue to believe in a high confidence winter storm for at least 
the Sierra slopes and a moderate to high confidence with QPF across 
the CWA. The lower elevations, particularly the Owens Valley are 
more of a question mark. Snow levels expected to drop to the valley 
floor level and produce snow Monday night into Tuesday, and 
potentially again Tuesday evening. The forecast continues to support 
snow for the northern half of the HWY 395 corridor in Inyo Monday 
and Tuesday, and possibly enough to accumulate and have some minor 
impacts even (2-4"). If that occurs, this could be the biggest early 
season snow in Bishop. Bishop has never seen 3 inches of snow before 
November 17. There is some potential to see even higher amounts of 
snow if the snow levels remain a bit lower. A winter weather 
advisory may be needed and will be evaluating further in the next 
shift or two.

AR events typically have fairly high snow levels and snow levels do 
stay elevated longer across Lincoln and Mohave Counties and to some 
extent Clark County. That could potentially limit some of the snow 
in those locations. 

As the AR shifts further down the California coast on Monday the 
plume of IVT values remains quite high from San Bernardino County 
and northeastward into Clark, Lincoln and Mohave Counties. The 
ensembles and several deterministic models are indicating very high 
probabilities of IVT values exceeding 250 units which is fairly 
unusual for inland locations. One to two inch liquid water 
equivalent or even isolated higher amounts will be possible by the 
time this system moves out.  

There is also the potential for wind advisories and/or high wind 
warnings for part of the CWA. The best opportunity for the strong 
winds will be during the day on Monday ahead of the precipitation. 
Winds aloft (700 mb) will be 50-60 kts from San Bernardino County 
northeastward into Clark, Nye and Lincoln Counties during much of 
the time. We'll need to hone in on the time frame as once the 
precipitation moves that should reduce drag and somewhat limit wind 
potential from there after, other than maybe at the highest 
elevations. 

As was previously mentioned as a potential evolution, the ensembles 
have delayed the exit of the upper low/trough, with the 
precipitation lingering throughout much of the forecast area on 
Wednesday. At this time, both the GEFS and EPS ensemble means push 
the trough axis to the east of the area Wednesday night and along 
with it all of the precipitation. Behind the system will be much 
colder conditions with temperatures remaining at least 10 to 15 
degrees below normal into Saturday with zonal flow to slight ridging 
enabling dry conditions through the period.
&&

.AVIATION...For Harry Reid...Light winds 8kts or less can be 
expected at the terminal into Sunday morning. Directions will favor 
easterly components into the early evening before turning the 
typical southwesterly direction for the overnight period. Winds will 
increase late in the TAF period with a few gusts out of the 
southwest to near 20 kts possible after 21Z tomorrow. No significant 
cloud cover is forecast through Sunday.  

For the rest of southern Nevada, northwest Arizona and southeast 
California...Light winds of 10kts or less can be expected across the 
region today and tonight. The one exception will be KDAG where 
southwest winds with gusts to 20kts are forecast to develop after 
22Z and then continue into Sunday morning. SCT to BKN high clouds 
will continue to move across the region today, but no operational 
impacts are expected.

&& 

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

$$

UPDATE...Pierce

SHORT TERM...Czyzyk
LONG TERM...Czyzyk
AVIATION...Planz

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