Scientific Forecaster Discussion
fxus65 kvef 252124
Area forecast discussion
National Weather Service Las Vegas Nevada
224 PM PDT Sat Mar 25 2017
Synopsis...a few showers will linger early this evening across
Lincoln and northern Mohave County as a low pressure system starts
to head east out of the area. High pressure will bring dry
conditions Sunday with fairly light winds and above normal
temperatures. Another storm will move across the area Monday through
early Tuesday leading to cooler temperatures, gusty winds and a
chance of showers.
Short term...through Monday night.
An upper trough was bringing gusty winds, clouds and a few showers
to the area this afternoon. Measurable precipitation was mainly over
Lincoln County and northern Mohave County and showers may linger in
those areas into early this evening. Decreasing winds and clouds can
be expected overnight as the trough moves into the Rocky Mountain
region and high pressure pushes in. High pressure over the area
Sunday will result in dry conditions with lighter winds and
temperatures a little above normal. A very weak shortwave trough
will clip the far northern part of the forecast area Sunday night
leading to a slight chance of showers mainly over Esmeralda and
northern Lincoln counties. A deepening upper trough will drop
southeast into Nevada Monday and into northern Arizona Monday night.
Shower chances will spread across a good portion of the forecast
area but mainly north and east of Las Vegas. Lincoln County will
have the best chance of precipitation and northern portions of the
County could see over a quarter inch of liquid precipitation.
Snowfall accumulation will be limited to the highest terrain with
around an inch possible. As the deepening trough start to drop down
on Monday we will see strong west to southwest winds develop across
portions of San Bernardino and Mohave counties and possibly southern
Clark County. Meanwhile, strong northerly winds will develop behind
a cold front across Esmeralda and central Nye counties. It looks
like those strong northerly winds will then spread into Inyo County
late Monday and Monday evening. Breezy to locally windy north winds
are likely over much of the forecast area during the overnight hours
Monday night. Based on the latest model guidance, we will likely
need to be issuing a Wind Advisory for several zones for Monday and
Monday evening. Will hold off on issuing for now to see how later
model runs trend with location and timing of the strongest winds.
Long term...Tuesday through Sunday.
Tuesday will see a building ridge over the region behind a departing
closed low. This will result in mostly sunny skies but persistent
breezy north winds down the Colorado River. Areas near Laughlin can
expect fairly strong winds during this time and wind advisories are
a good bet as we approach the event. Winds will decrease on
Wednesday and temperatures will climb a few degrees above normal
ahead of the next weather system set to move in late in the week.
Much uncertainty remains during the Thursday-Sunday time period as
yet another trough is expected to dive towards the southwest. This
mornings 12z European model (ecmwf) model is quite cold and bullish developing a very
strong closed low over the region by Friday morning. Meanwhile, the
GFS is weaker and more progressive with this feature. Both models
have been flip flopping back and forth with the details of this
system so confidence remains poor at best, but there will be the
potential for another shot of cool and unsettled weather late in the
week, especially if the colder European model (ecmwf) solution were to verify. For
now, advertised only a slight cooling and very modest increase in
precipitation chances to the region, but additional adjustments can
be expected as models converge on a solution over the next few days.
Aviation...for McCarran...cloud bases of 8-10 kft will persist
along with some showers near the Spring Mountains into early this
evening. Northwest 10-15 knots with gusts to 20 knots will likely
persist with lighter west/southwest winds developing after sunset.
Clouds will also clear out after sunset. Light winds favoring an
easterly component are expected most of the day Sunday.
For the rest of southern Nevada, northwest Arizona and southeast
California...scattered showers will persist into early this evening
mainly across Lincoln and northern Mohave counties. Otherwise expect
clearing skies tonight with mainly high clouds Sunday. Gusty west to
northwest winds into early this evening will decrease overnight with
fairly light winds in most areas Sunday. The exception Sunday will
be western San Bernardino County where west winds 15-20 knots and
gusts 25-30 knots are possible.&&
Spotter information statement...spotters are encouraged to report
any significant weather or impacts according to Standard operating