Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Reno Nevada
326 am PST Tuesday Dec 1 2015


High pressure will produce valley inversions and reduced air quality
through Wednesday. A modest winter storm brings gusty winds and
mountain snow Thursday and Thursday night, with lighter rain and
snow for lower elevations. The main storm track will stay north for
the weekend with mostly dry conditions and temperatures near
seasonal averages.


Short term...

No major changes to the short term forecast.

Mixing for valleys will remain limited for the next couple days
with winds near ridge level staying generally below 20 kts. The
air quality alert and red burn code remain in effect through at
least today for the Reno-Sparks and Washoe Valley areas.

Late tonight and Wednesday morning, a period of warm advection
could bring some light precipitation to areas north of a Portola
to Susanville to Gerlach line. Model soundings are showing an
isothermal layer near or slightly below freezing so most
precipitation should be in the form of snow, with perhaps a mix
for areas below ~5000 feet if warmer air winds up mixing into the
valleys. This looks rather unlikely at this time given stable
profiles in the lower levels and modest wind aloft, although
precipitation amounts will remain light so only very light
accumulations are expected across far northeast California and
northwest Nevada into Wednesday morning.

Turning to the system due in for Thursday, it still appears to be
a modest shot of snow for the northern Sierra and northeast
California, especially above 5000-5500 feet. Snowfall totals of 5
to 10 inches in the northern High Sierra, with 3 to 6 inches in
the Tahoe basin and northeast California (west and south of
susanville) look reasonable at this time. With the best forcing
over far northeast California, the Mono County Sierra should see
less snowfall although 3 to 6 inches will still be possible near
the crest.

Spillover east of the Sierra looks meek as the jet remains over
or north of I-80 for shallower moisture/weakening upper forcing
as the system's front moves into Nevada. Therefore, a light
dusting or so out into the foothills of far western Nevada is all
that is expected at this time.

More significantly for the Lee of the Sierra, winds will increase
substantially Thursday with much better mixing than previous
days. With flow aloft backing towards southerly, north-south
facing valleys in far western Nevada and areas along Highway 395
in southeast Lassen County could see widespread winds of 20 to 35
miles per hour with gusts to 55 mph, especially as precipitation approaches
the Sierra Thursday afternoon. Note that with southerly winds the
foothills west of Reno and Carson City may not have any stronger
winds than along Highway 395. The southerly wind flow will also
favor enhanced winds from Meyers to South Lake Tahoe ahead of the
precipitation as winds are channeled down the valley. Snyder

Long term...Friday through Monday...

Upper trough will be exiting the area Friday with lingering showers
mainly in the morning. Overall, the weather picture will be one of a
mix of sun and clouds with temperatures just slightly below seasonal
normals. Mixing and ventilation will be good on Friday on back side
of trough. A shortwave ridge of high pressure will move across the
area Saturday for light winds and a brief return to the strong

For the weekend into next week, a west to northwest flow pattern is
going to set up across the east Pacific into the western Continental U.S. With
fast moving shortwave features moving across the pacnw and into the
northern Great Basin and northern rockies. One shortwave will bring
a chance of showers sun-Sun night with a second weaker system brushing
the area late Monday. These are not big storms with precipitation
expected to be light. This pattern is also a milder pattern with
frequent periods of middle and high level clouds. So temperatures will
be mild for early December with inversions overall weaker. Hohmann



Light winds and VFR conditions will prevail across the terminals
through Wednesday. Only exception is for ktrk where patchy fzfg will
continue through late this morning. Increasing high cloud cover may
limit fzfg at ktrk for late Tuesday night/early Wednesday but cannot be
completely ruled out. Mjd


Rev watches/warnings/advisories...


For more information from the National Weather Service visit...
http://weather.Gov/Reno (all lower case)

National Weather Service Glossary of Abbreviations