Area Forecast Discussion
Issued by NWS Las Vegas, NV

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FXUS65 KVEF 211250

Area Forecast Discussion
National Weather Service Las Vegas NV
450 AM PST Sat Jan 21 2017

.SYNOPSIS...Drier conditions are expected today...but the break
will be short lived as another potent system brings widespread rain,
mountain snow, and gusty winds to the region tonight through
Monday. Drier and cool conditions are then in store for Tuesday and

.SHORT TERM...Today through Monday Night.

Another busy morning with the second storm of this series winding
down today and the third set to impact the region tonight right on
through Monday.

Isolated to scattered showers continue across Lincoln and Mohave
counties this morning. These will gradually shift south and end
through the day. I left the Winter Weather Advisories and Winter
Storm Warning in effect for those areas as additional light snow
accumulations are possible (generally less than 4 inches). Otherwise
the region will be drying out somewhat today.

The next system will begin to impact the Sierra late this evening.
Rain and mountain snow showers will then spread east of the Sierra
early Sunday morning, likely reaching the I-15 corridor around
daybreak. Through the day Sunday, expect the brunt of the
precipitation to develop along and north of the I-15 corridor, with
considerable spillover into the valleys and deserts east of the
Sierra. As a result, expect significant snow to begin falling in
those areas above about 4000 feet during the morning hours. Snow
levels will rise to 4500-5000 feet by the afternoon, then fall again
Sunday night as the low pressure system and it`s colder air aloft
invade the region. This will also create widespread windy conditions
Sunday through Monday. Precipitation will gradually shift southeast
impacting more and more of Arizona Sunday night into Monday.
Confidence in where and when precipitation fall Sunday night into
Monday is lower than for Sunday. It does appear as if some sort of
secondary band may develop during this timeframe, but agreement in
placement and timing is poor. Precipitation will taper off from
west to east Monday afternoon through Monday night.

Notable items:
* Focused the brunt of the precipitation on areas along and north
  of the I-15 corridor, especially Sunday.
* Added Winter Weather Advisories for the Owens Valley and Northern
  Mohave County for the upcoming storm.
* All winter weather products now include all areas above 4000 feet
  (was 5000 feet previously).
* Added a Wind Advisory for the western Mohave Desert and Colorado
  River Valley north of Bullhead City not already included in a
  winter weather product. Advisory level winds may be somewhat
  spotty at times, however the combination of strong winds and slick
  roads will increase road hazards.
* Made no changes to the Flood Watch for Lincoln, northern Mohave,
  and northwest Clark County. It is possible that areas may need to
  be added (or removed) as we get closer to the event. Most likely
  additions include the lower elevations of Inyo County where the
  most spillover is likely to occur.

.LONG TERM...Tuesday through Saturday.

A much deserved break in the parade of Pacific storm systems is
expected for the extended range as broad troughing shifts into the
Central US and ridging takes hold of the West Coast. We will remain
on the cyclonic and cool side of the trough through Friday so
temperatures will remain below normal but dry conditions are
expected.  Occasional bouts of gusty north winds down the Colorado
River Valley will be possible as well, especially Friday and
Saturday. As the ridge continues to build into next weekend,
temperatures warming back to near or even above normal levels can be

.AVIATION...For McCarran...Relatively low confidence wind forecast
today as either southwest or northwest winds will materialize but not
confident on which will win out. Anticipate the most likely scenario
is west or southwest winds persisting through the day, but there is
an outside chance they may go northwest during the mid morning
through mid afternoon period. Wind gusts may reach into the 20 knot
range. Sky conditions will be mostly clear with just a few clouds
near the higher terrain. Increasing mid and high clouds expected
Saturday night.

For the rest of southern Nevada...northwest Arizona...and southeast
California...Breezy west winds expected across the Mojave desert
with gusts to 40 knots near KDAG and KNXP. Improving sky conditions
expected through the day with clouds become few-scattered by the end
of the day.  Increasing clouds will return saturday night with
showers returning to the KBIH area after 06z.

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
rain and snow amounts from yesterday`s storm system. Yet another
storm is expected tonight through Monday.


Short Term...........Wolcott
Long Term/Aviation...Outler

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