Area Forecast Discussion
Issued by NWS Las Vegas, NV
FXUS65 KVEF 232134
Area Forecast Discussion
National Weather Service Las Vegas NV
235 PM PDT SUN OCT 23 2016
.SYNOPSIS...A Pacific storm system will impact the region tonight
through Monday. This will bring increased cloudiness as well as
chances for rain and isolated thunderstorms. More tranquil weather
is expected during the middle of next week before another series of
storms takes aim at the region late in the week through next weekend.
.SHORT TERM...Through Wednesday Night
As for our current products. Based on latest observations and
guidance having a hard time justifying the Wind Advisory so am going
to cancel that product with the afternoon issuance. It does look
breezy to locally windy this afternoon and Monday in parts of Nye,
Esmeralda and Lincoln Counties but not widespread enough for
So far more bark than bite in regards to rainfall. Lots of mid/high
level moisture streaming into the Mojave Desert/Southern Great Basin
but little in the way of dynamics or instability to help generate
any more than virga or probably just a light rain shower at the
As the air mass continues to undergo moistening from the mid-levels
down to the surface tonight stronger dynamics should start to come
into play as jet noses into Southern California placing much of the
Mojave Desert and southern Nevada under the left front exit region.
Some discrepancy between the operational models and HRRR on exactly
where north/south lines of showers/embedded thunderstorms develop.
The operational models remain consistent developing a line between
the Morongo Valley-Spring Mountains-Caliente. Meanwhile, the HRRR is
further west between Ridgecrest-Beatty-Ely. In the end, both
solutions may turn out correct so did not much change to inherited
POP grids which paint the highest POPs in a corridor between Las
Vegas and Beatty tonight/Monday morning. By Monday afternoon the
lines should start dissipating with showers/thunderstorms becoming
more scattered in coverage under slightly more unstable air mass.
Any residual showers/thunderstorms will come to an end Monday night
as dry/more stable air mass develops under building ridge of high
pressure. High pressure stays in control of our weather regime
Tuesday and Wednesday.
.LONG TERM...Thursday through Sunday.
Southwest flow over the area with high pressure to the east and
troughing to the west on Thursday with extended models in agreement.
However, as with previous model runs differences really start to
show up Friday through the weekend. The ECMWF continues to be the
much faster and more progressive model compared to the slower GFS
and Canadian runs. By Thursday afternoon the ECMWF already has
precipitation reaching the southern Sierra while the other models
don`t bring in it until Friday morning. The one thing that the
models basically agree on is the placement of the main rain band
which stretches from far western San Bernardino County up through
Inyo and eventually across Lincoln County while leaving Clark,
eastern San Bernardino, and Mohave Counties generally dry except for
some light scattered showers. Went ahead and kept the current
rainfall timing alone in the grids due to the continued uncertainty,
but upped the pops for Inyo and Nye Counties with likely in the
higher terrain of Inyo. The southwest flow into the Sierra should
help limit how much rainshadowing occurs with a good possibility of
a decent rain event for Inyo County. Although the timing is off on
the models it looks like much of the precipitation will be out of
the area by Saturday as high pressure quickly reestablishes itself
over the area. This would bring a quicker warming trend back to the
area Saturday and Sunday. Even on Friday with the thicker clouds,
most areas will continue to see slightly above normal temperatures.
.AVIATION...For McCarran...Light winds are expected through the
evening. However, with some of the showers and potential
thunderstorms that will move toward the area its possible that some
stronger winds associated with these storms will move into the
valley. The best window for this happening will be between 02z-08z.
Showers will also be possible in the valley, but thunderstorms look
to remain west and northwest. Cigs down to 8-10K feet overnight.
Scattered showers possible through midday Monday with cigs around
10k feet and south winds increasing to around 10-20kts in the
For the rest of southern Nevada...northwest Arizona...and southeast
California...Scattered showers and thunderstorms expected overnight
and Monday with a drying trend from west to east Monday afternoon.
Cigs around 8-10k feet over most areas. Gusty winds will continue
this evening for Inyo, Esmeralda, and central Nye Counties with
south winds over most areas Monday 10-20kts.
.FIRE WEATHER...Expanded the Red Flag Warning to include Fire Zone
460 as local red flag conditions are being met. Winds will diminish
tonight only to increase again Monday. Humidity levels will be
higher on Monday so there is not threat of Red Flag conditions being
met. Drier and more stable weather is in the forecast Tuesday
through Thursday with unsettled weather returning late in the week
and next weekend.
.SPOTTER INFORMATION STATEMENT...Chances for rain and perhaps
isolated storms will increase on Sunday and Monday. Spotters should
report significant weather according to standard operating
Short Term/Fire Weather...Pierce
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