Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Las Vegas Nevada
300 PM PST Friday Dec 19 2014
Synopsis...a weak system will move across the area through Saturday
with just a few showers possible in the Sierra and the higher
elevations of the southern Great Basin. The remainder of the area
will see an increase in high clouds. High pressure is expected to
strengthen off the coast of California on Sunday and hold through
Tuesday keeping the area dry and mild. Another system may impact the
area Christmas evening into Christmas day.
high level clouds pushing across the region this afternoon ahead of
a weak system that is currently moving into the Pacific northwest.
Regional mosaic radar showing some light showers moving through
central California which will reach the southern Sierra and
mountains of Esmeralda County this evening. Any showers that do fall
are expected to remain light and any upper elevations snowfall
/above 6500 feet/ will remain well below advisory levels. This
system will continue to push east tonight with only a slight chance
of showers for Esmeralda...central Nye and northern Lincoln
counties. High pressure will start to strengthen over the eastern
Pacific late Saturday and slowly drift east by Sunday. A drier
northwest flow will set up over the area through Monday...but
surface high pressure is forecast to build over Idaho and move into
Wyoming Monday evening and Tuesday. This will cause the surface
gradient to increase down the Colorado River valley and bring some
gusty north winds to the area...especially around Laughlin/Bullhead
City. By Tuesday afternoon the high pressure ridge will move over
the area bringing light winds and above normal temperatures.
Readings by middle week may be as high as 10 degrees above normal.
However...surface inversions may help keep those numbers down a
little. Beyond Wednesday gets a little tricky as the GFS/European model (ecmwf)
differ on a potential trough moving into the area on Christmas day.
It does look like winds will start to increase Wednesday
afternoon...which will likely make Wednesday the warmest day of next
week and then a cold front will move through on Thursday.
However...the strength of the front and how far south this system
digs in also in question. For now it does look like we will see some
windier and cooler weather on Christmas with the potential of
showers at least across northern and central Nevada.
Aviation...for McCarran...mainly broken clouds with bases lowering
from around 25k feet this afternoon to around 15k feet this evening
and Saturday. Winds should be 6 kts or less and favor typical
diurnal directional trends.
For the rest of southern Nevada...northwest Arizona...and southeast
California...sct-bkn clouds at or above 25k feet with bases lowering to
10-15k feet through tonight. Winds will be 6 kts or less and trend
toward typical diurnal directions through tonight. A few showers
will be possible across the Sierra...Esmeralda...central Nye and
northern Lincoln counties.
Spotter information statement...spotter activation is not expected.
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