Area forecast discussion
National Weather Service Reno Nevada
231 PM PDT Friday may 24 2013
Synopsis...
low pressure will remain over the Pacific northwest through Sunday
then move inland on Memorial Day. The low will produce a chance
of showers Saturday and Sunday north of Susanville and Gerlach
along with gusty winds across the eastern Sierra and western
Nevada. The chance for showers and high elevation snow in the
Sierra increases during the afternoon on Memorial Day as the low
moves inland.
&&
Short term...
No large changes to the forecast for the start of the Memorial Day
weekend. The persistent low over the Pacific northwest will
continue to produce gusty afternoon and evening winds, with gusts
of 30-35 miles per hour possible. The strongest winds will occur on Sunday as
a piece of energy rounds the base of the low along the California-
Oregon border. This wave will increase the winds aloft along with
a 15-20 degree surface thermal gradient between the Tahoe basin
and Carson/Humboldt sinks. Boaters on area lakes, especially
Tahoe, pyramid, lahontan, Topaz and Crowley, will want to be very
cautious Saturday and Sunday with choppy lake conditions developing
by middle afternoon and lasting until an hour or two after sunset.
For precipitation chances: only the NAM is hinting at showers may
develop across northern Lassen and Washoe counties on Saturday,
with surface convergence and minimal instability. The better
chance for showers and thunderstorms is Sunday, when the aforementioned
wave brings a boost of instability to areas north of Portola-
Pyramid Lake. The NAM also tries to develop a few showers over
Pershing and Churchill counties early Sunday evening, but with
very low surface dew points rainfall is unlikely to reach the
ground.
Temperatures will warm a few degrees Saturday with better mixing.
Nevada Valley highs will climb well into the 70s and perhaps reach
80 in Mineral, Churchill and Pershing counties. Highs in the
Sierra will reach the 60s this weekend. Overnight lows will remain
on the cold side, especially in the Sierra valleys where lows will
dip into 20s. Brong
Long term...Monday through Friday...
On Monday a strong east Pacific jet will begin to push a stronger trough
through the Sierra and western Nevada. Isolated showers will begin
in the Sierra on Monday afternoon and become more widespread into
Monday evening. A few inches of snow is possible Monday night
above 8000 feet after the main front pushes into western Nevada.
Slushy snow accumulations may affect Holiday travel late Monday
night on the highest Sierra passes. At this time snow levels are
expected to remain above Donner Pass.
Main changes to the forecast was to continue to increase probability of precipitation for
Monday and Tuesday especially along the Sierra crest and add light
snow accumulations above 8000 feet Monday night. Also continued to
drop temperatures Monday and Tuesday.
By Tuesday significant model discrepancies begin as the European model (ecmwf) allows
the trough to deepen into southern Nevada and closes off a small
area of low pressure. This would bring considerably more
precipitation to central Nevada. Leaning toward the GFS as there is
limited ensemble support from either the GFS or European model (ecmwf) for this
solution.
Wednesday a few lingering showers are possible mainly in the far
northern Sierra. Wednesday through Friday temperatures will begin to
rebound to a few below normal with clearing skies. Tolby
&&
Aviation...
Low pressure remains over the Pacific northwest with gusts near 25
kts through 04z. Afternoon and evening winds will return Saturday
and Sunday, with peak surface gusts nearing 30kts. Gusts could be
a bit stronger Sunday as a wave passes across northeast
California.
This wave will also increase the chance for showers and
thunderstorms north of Portola-Pyramid Lake, though conditions
will likely remain at VFR. Brong
&&
Rev watches/warnings/advisories...
Nevada...none.
California...none.
&&
$$
For more information from the National Weather Service visit...
http://weather.Gov/Reno (all lower case)
