Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Reno Nevada
305 PM PDT Tuesday Jun 2 2015
There will be a low chance for thunderstorms north of Susanville
and Gerlach on Wednesday. Thunderstorm chances expand over the
Sierra and western Nevada Thursday as low pressure drops into
California. Chances for showers and thunderstorms will linger
through the weekend. Temperatures will remain around average.
Modest cumulus have developed as expected across northern Lassen
and Washoe counties. With the main upper forcing over eastern
Oregon, I do not expected anything more than brief sprinkles from
the cumulus through this evening. The only exception may be over
the northern Surprise Valley, where brief light precipitation is possible
this evening along a more robust line of cumulus extending across
For late tonight through Wednesday afternoon, an upper wave
evidenced by high clouds off the California coast (around 130w)
will move over eastern California and western Nevada. This is not
expected to do more than bring high clouds, with the exception
across northern Lassen and Washoe counties where surface convergence
and slight cooling/destabilization aloft with the wave could bring
a few showers and thunderstorms Wednesday afternoon and evening.
Thursday, energy currently pushing across the North Pacific will
split as it runs into a mean ridge over northern Canada. One
piece of energy will dive south around the ridge into northern
California, putting the northern Sierra and far western Nevada in
the deformation zone of the low. The lift/cooling aloft from the
low will combine with daytime heating to encourage the development
of scattered afternoon and evening showers and thunderstorms.
Operational models seem to be pegging eastern California, the
Sierra and far western Nevada for the highest precipitation
amounts and have been doing so for a few runs. Therefore, I have
begun bumping up pop in that area with more significant bumps
possible with the next few model runs. Snyder
Long term...Friday through Tuesday...
Models are relatively close in tracking a cut off low along the
Southern California coast on Friday to over northern Nevada by
Sunday. Main impact is increasing chances for showers and
thunderstorms for the weekend. With the nature of cut off lows, it
is difficult to Pin Point favored locations this far out. However
there is a trend in the best chance of showers and thunderstorms
south of I-80 on Friday, shifting to north of US-50 for Sunday and
Monday. By Tuesday, a second low may reach the California coast but
with only a very low potential of showers and thunderstorms near the
There are two tropical systems in the eastern Pacific, Andres and
Blanca. Model trends over the last few days suggest any moisture
from these systems will go into northern Mexico and Arizona with
little if any reaching the eastern Sierra and western Nevada. If we
were to get any moisture, it would only show up as high clouds for
the start of next week. Brong
VFR conditions with surface wind gusts up to 25 kts through 04z.
Low pressure will track south along the West Coast on Wednesday,
with a few showers possible north of Susanville-Gerlach and gusty
afternoon/evening winds up to 25 kts.
By Thursday the low should be centered south of ksfo with potential
for showers and thunderstorms over the Sierra and western Nevada.
MVFR conditions with a mix of rain/ice pellet showers are possible
as freezing levels drop below 12,000 feet mean sea level. The low is forecast to
hang around through the weekend for a continues threat of
showers and thunderstorms. Brong
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