Area Forecast Discussion
Issued by NWS Las Vegas, NV

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FXUS65 KVEF 161052

Area Forecast Discussion
National Weather Service Las Vegas NV
252 AM PST Mon Jan 16 2017

.SYNOPSIS...Quiet weather will persist through the middle of the
week. The next pair of storm systems will impact the region late
Wednesday through the weekend bringing more widespread rain and
mountain snow to the region. Temperatures will continue to run near
to slightly below normal.

.SHORT TERM...Monday through Wednesday Night.

Tranquil conditions are expected across the majority of the region
through Wednesday. One concern today are the areas of low clouds
and patchy freezing fog across the valleys of far northern Mohave
County, northeast Lincoln County, and Esmeralda County. Depending on
how much mixing occurs today, these conditions could persist through
Tuesday. The other concern is northerly winds, mainly down the
Colorado River Valley near Laughlin/Bullhead City, where gusts up to
30-35 MPH are possible. These winds should settle down for Tuesday
as the pressure gradient relaxes across the area.

Attention then turns to the next pair of storm systems expected to
impact the region late Wednesday through the upcoming weekend. The
first of these storms will begin to impact the region at the end of
the short term period, Wednesday night spreading precipitation from
the Sierra east across much of the forecast area by daybreak
Thursday. Snow levels will be falling from 7000-8000 feet down to
around 5000 feet during this time.

.LONG TERM...Thursday through Sunday Night.

Confidence in an active end to the week is increasing. Model
agreement is fairly high overall, with forecast confidence limited
mainly by the forecast length, with plenty of changes...especially
in details...likely by late week.

The first in a series of troughs will roll across the area quickly
on Thursday, with snow levels dropping to around 5000 feet as it does
so. QPF amounts look to be up to about a tenth of an inch for most
of the deserts, with a little more modest snow amounts for the
Sierra. Breezy to gusty west to south/southwest winds expected
across most of the area Thursday as well.

The area will see a brief lull in activity Thursday night into
Friday before the second system begins to impact the area by Friday
afternoon. This trough looks to have a much better moisture tap, so
higher QPF amounts are likely, with confidence increasing in
significant snowfall above 5000 ft. Snow levels could even drop as
low as 4000 ft in some places. West to south/southwest winds will
kick up once again by Friday afternoon as well.

The area will receive another break on Saturday before yet another
trough takes aim at the region on Sunday. This system`s impacts look
to have a longer duration than the previous two systems,owing to the
larger size of the trough. Operational models are coming into a bit
better agreement on timing, breaking out precipitation for western
portions of the area, and increasing southerly winds for most of the
area by Sunday evening, with precipitation overspreading the region
on Monday. The overall system looks another step colder than the
previous, with snow levels likely around 4000 ft or so, with another
decent moisture tap off the Pacific. Confidence in significant snow
above 4000 ft for this system is increasing, however is still on the
lower end due to the long forecast range.

.AVIATION...For McCarran...VFR conditions through the period, with
just some mid to high clouds this morning. North-northwest winds
will increase between 16-18z and will then transition to a
northeast direction shortly thereafter. Speeds are generally
expected to be in the 8-12kt range, with occasional gusts of 15-20
kts. Winds will decrease in speed around sunset, after which wind
direction may vary between southwest and northerly. Lighter winds
are expected Tuesday.

For the rest of southern Nevada...northwest Arizona...and southeast
California...Outside of the valleys of central Nevada where
low clouds persist, VFR conditions are expected across the region.
Winds will generally favor a northerly direction at 8-15 kts in most
areas, with stronger winds in favored locations such as the Colorado
River Valley near KIFP and KEED where gusts to around 30 kts can be
expected. Lighter winds are expected areawide by Tuesday.

.SPOTTER INFORMATION STATEMENT...Spotter activation is not expected
through Wednesday.


Short Term/Aviation...Wolcott
Long Term.............Steele

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