Scientific Forecaster Discussion
fxus65 kvef 130458
Area forecast discussion
National Weather Service Las Vegas Nevada
858 PM PST Thu Dec 12 2019
Synopsis...slightly warmer than normal temperatures are expected
through Saturday along with considerable high clouds. The next
weather system rolling out of the eastern Pacific could bring strong
winds and increased shower chances to portions of the southern Great
Basin and Mojave Desert late Saturday and Sunday. A cold air mass
will filter in next week, returning temperatures back to slightly
Update...the forecast looks in pretty good shape at this point.
Periodic, denser patches of high clouds continue to pass across
the area from time to time and this will likely be the case for
the overnight hours. More interestingly, satellite imagery is
showing wave clouds over parts of the Owens Valley in Lee of the
Sierra and also developing low clouds across portions of
southcentral Nevada this evening. These can be attributed to a
weak, barely discernible disturbance passing well north of our
area and currently producing light shower activity over extreme
Previous discussion... /issued at 245 PM PST Thu Dec 12 2019/
Discussion...through next Thursday.
Other than high clouds, the region will remain quiet through much of
Friday before the next trough begins to move into the Pacific
northwest. Precipitation chances will increase across mainly the
western slopes of the Sierra Friday afternoon into Saturday morning.
There will some gradual spillover into the eastern slopes, but snow
amounts are generally expected to remain light...although some of
the highest peaks could see over a foot of new snow. Down to around
8000 feet accumulations should be closer to just a few inches, but
at this time totals are expected to remain below advisory levels.
There will also be a quick brush-by of snow to northern Lincoln
County, but snow totals are expected to remain less than just a
couple of inches. A second through will dig into the Great Basin
Saturday afternoon and Sunday. Most of the energy associated with
this system will remain across northern Nevada and Utah, but the
models are indicating a weak front that will push through southern
Nevada and Arizona late Saturday afternoon and evening. This front
is not particulary strong, but will have enough moisture and
dynamics to produce a few showers as it moves through the region.
Rainfall amounts are expected to remain less than a tenth of an inch
with just a couple of inches of snow in the mountains. There could
also be a lightning strike or two in Lincoln County as this front
sags south. The best chance of seeing rain in the Las Vegas Valley
will occur late Saturday evening and overnight.
Conditions will improve Sunday and next week as ridging develops
over the West Coast. This will bring drier conditions along with
temperatures warming to a few degrees above normal.
Aviation...for McCarran...light, diurnal winds will continue
through Friday afternoon under bouts of high clouds. No operational
impacts are expected.
For the rest of southern Nevada, northwest Arizona and southeast
California...light winds will continue at regional airfields through
at least Friday morning. By Friday afternoon a few locations - kbih,
kdag & kifp - will see increasing winds in response to a passing
weather disturbance. Winds will increase to 10-25 knots and persist
through Friday evening. Scattered to broken high clouds are expected
Spotter information statement...spotters are encouraged to report
any significant weather or impacts according to Standard operating