970
FXUS65 KVEF 232211 CCA
AFDVEF

Area Forecast Discussion...CORRECTED
National Weather Service Las Vegas NV
211 PM PST Sat Nov 23 2024

.SYNOPSIS...Gusty southwest winds are spreading across the region
today while high elevation snow falls across the Sierra. Winds
will weaken by Sunday. The next system will move across the region
during the first half of next week, bringing widespread chances
for rain and mountain snow. A major snowfall event is expected in
the Sierra above 8000 feet with this event. Cooler and drier
northwest flow is expected by the end of the week.

&&

.SHORT TERM...Tonight through Sunday Night.

Gusty southwest winds have spread across much of the Mojave Desert
and southern Great Basin today.

* For the Sierra/Owens Valley: Most of the downslope winds peaked
  early this morning, but a window for additional strong gusts
  remains open through about 4 PM this afternoon before gradually
  decreasing overnight.
* For the Spring Mountains/Red Rock Canyon/Desert Rock areas: A
  brief peak in downslope winds occured early this morning.
  However, another window for strong downslope winds is possible
  between roughly 2 PM and midnight before a general decreasing
  trend begins through Sunday morning.
* Elsewhere: gusty southwest winds will peak between now and 9 PM
  today generally from north to south across the far southern Great
  Basin and Mojave Desert.

Areas of blowing dust have also been seen today, particularly
from the Jean dry lake bed south of the Las Vegas valley. No
additional changes are currently planned for the wind headlines in
place, but we will continue to monitor trends and short range
guidance.

Snowfall rates have generally decreased across the Sierra since
about 10 AM this morning. Will keep the advisory going for the
moment to monitor trends, but it`s possible the advisory can be
cancelled well before its 12z expiration time.

Looking forward, conditions will generally calm and dry through
Sunday. The exception may be across Nye and Lincoln counties where
a chance for rain/high elevation snow will exist.

.LONG TERM...Monday through Friday.

Details in the long term continue to be a challenge due to the
presence of outlier solutions. The overall pattern will consist of
a trough pushing east across the western CONUS followed by drier
and cooler northwest flow. The question continues to be in the
details of how quickly this progression. A 65% majority of members
indicate that this will happen relatively quickly Monday through
Tuesday. On the opposite end of the spectrum, around 10% of
members indicate this lingering all the way through at least
Wednesday, with the remainder somewhere in between. The majority
solution would spread precipitation across the northern 1/2 of the
CWA (generally north of the I-15 corridor) Monday and Tuesday then
bring cool and dry northwesterly flow in by Wednesday while the
slower solution would keep precipitation chances and warmer
temperatures going through at least Wednesday.

The evolution will also have significant implications on the
forecast in the Sierra where a major snowfall event is likely.
Snow levels will generally hover between 7500-8000 feet during the
core of this event. If this event drags on into Wednesday, it may
significantly increase snowfall totals in the Sierra (and to a
lesser extent, the White Mountains). Currently, 60-hour snowfall
totals with this system are on the order of 1.5-2 feet of snow
down to Aspendell, with 3-4.5 feet of snow near the Sierra crest.
Snowfall rates during the peak of this event could approach 2
inches per hour at times.

As mentioned, drier northwesterly flow is expected behind this
system during the latter part of the week. A weak area of low
pressure may undercut the ridge by the weekend but at this point,
minimal impacts are expected from that system.

&&

.AVIATION...For Harry Reid...25 to 35 knot southwesterly wind gusts
will continue through the afternoon and into the early evening
hours. These gusty southwesterly winds will kick up dust from
downstream dry lakebeds, which may result in slantwise and surface
visibility reductions should the dust push into the Las Vegas
Valley. Winds will become more southerly and will gradually decrease
throughout the evening and overnight hours. By early Sunday morning
wind gusts should have dropped off with sustained 10 to 15 knot west-
southwesterly winds expected to continue through the late morning
hours. Late tomorrow morning winds will swing around to a more
easterly direction with sustained speeds of less than 10 knots.

For the rest of southern Nevada, northwest Arizona and southeast
California...The remaining Las Vegas Valley TAF sites will see 25 to
35 knot southwesterly wind gusts will continue through the afternoon
and into the early evening hours. These gusty southwesterly winds
will kick up dust from downstream dry lakebeds, which may result in
slantwise and surface visibility reductions should the dust push
into the Las Vegas Valley. Winds will become more southerly and will
gradually decrease throughout the evening and overnight hours. Winds
winds in the Colorado River Valley will favor a more southerly
direction, with wind direction varying between 150 and 200 degrees.
Unlike the Las Vegas Valley, the Colorado River Valley TAF sites
will struggle to gust, with sustained speeds topping out around 7 to
12 knots this afternoon. Winds will decrease throughout the evening
before becoming light and variable through the overnight period.
KDAG will maintain a westerly direction with 15 to 20 knot sustained
winds gusting in the 25 to 35 knot range. These winds will peak
later this afternoon/early this evening and will very gradually
decrease throughout the overnight hours. Breezy southwesterly winds
will continue at KBIH through mid-to-late afternoon at KBIH. Around
mid-afternoon winds will at KBIH will decrease and swing around to
the northwest. These northwesterly winds will continue through the
overnight hours before decreasing and becoming light and variable
once again early tomorrow morning. FEW to BKN mid-to-high clouds
will filter through the region, but are not expected to have any
operational impacts as CIGS will remain aoa 15 kft.

&&

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

&&

$$

DISCUSSION...Wolcott
AVIATION...Stessman

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