Area Forecast Discussion
Issued by NWS Las Vegas, NV
FXUS65 KVEF 111246 CCA
Area Forecast Discussion
National Weather Service Las Vegas NV
238 AM PST Sun Dec 11 2016
.SYNOPSIS...Weather conditions across the region will be mild and dry
through the middle of the week with considerable high cloudiness at
times. A shift in the weather pattern could usher in cooler and
unsettled weather later in the week with a sharp drop off in
temperatures expected next weekend.
.SHORT TERM...Through Tuesday night...
A generally mild, moist west to northwest flow aloft will continue
to bring mid and high level clouds across the area through the short
term. Temperatures are expected to be around 8-10 degrees above
normal for mid December and could be a little warmer by Tuesday with
gusty southwest winds mixing out the inversion and bringing warmer
air to the surface. In Las Vegas, this would mean afternoon highs
reaching the upper 60s.
Mainly light winds are expected through Monday except in the western
regions of the Mojave Desert where westerly winds 10-20 mph are
expected. Stronger winds return to the Sierra Monday night but at
this point are forecast to strongest near ridgetop. Gusty winds
spread into the Mojave Desert on Tuesday but look sub-advisory level.
.LONG TERM...Wednesday through Sunday.
The medium range models still indicate a significant change in our
weather shaping up, especially Thursday and Friday. The main feature
to keep an eye on is the plume of subtropical moisture being pulled
northeastward from the area around Hawaii. Wednesday, a weak ridge
over the western states will direct that moisture over northern
California/Nevada but a Pacific trough is forecast to drop down over
central California and southern Nevada late Thursday through Friday.
This will direct the stream of moisture across our forecast area and
confidence is a little higher that we will see precipitation. PoP
grids were increased accordingly. Confidence in amounts is still low
at this point and it looks like it will be a 6-12 hour window
Thursday evening into early Friday morning that will favor
precipitation for most sites within the area.
The moisture is forecast to be pushed east of our area by Friday
afternoon and we will see some cooler air move in going into the
weekend. The latest indications are that it will not be as cold over
our forecast area Saturday and Sunday as it appeared 24 hours ago.
The large cold trough dropping out of western Canada is forecast to
quickly head toward the Rockies and Northern Plains.
.AVIATION...For McCarran...Mainly high clouds are expected through
the period. Light WSW winds this morning becoming variable later in
the morning and continuing through the afternoon.
For the rest of southern Nevada...northwest Arizona...and southeast
California...Light winds are expected today across much of the area
except for steady west winds 15-25 kts impacting the western Mojave
Desert. Lower Cigs will continue at KBIH and east through
southcentral Nevada through daybreak with considerable high clouds
continuing throughout the day. Mountain tops obscured along the
Sierra and southern Great Basin this morning. Localized sc/cu
possible in the Mojave Desert with bases 7-10 kft agl.
.SPOTTER INFORMATION STATEMENT...Spotter activation will not be
needed today or Monday.
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