Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Reno Nevada
141 am PDT Tuesday Sep 16 2014
smoke and haze from the King fire will continue to impact the area
through Thursday. Temperatures will remain above normal with
breezy afternoons. Low pressure off the California coast will move
inland by Thursday. This will produce a slight chance of showers
and thunderstorms. High pressure should return by the weekend for
warm and dry conditions.
the main issue the next two days will be the smoke from the King
fire for northeast California and northwest Nevada. The main
smoke plume will ride northwest of Tahoe and into eastern
Sierra/Plumas/Lassen counties. However, the afternoon westerly
component of the Zephyr will bring smoke into the Tahoe basin and
Highway 395 Corridor North of Highway 50 similar to yesterday.
This will likely occur again Wednesday as long as the fire
continues to remain very active.
Otherwise, expect a slight increase of winds from the SW each day
with Wednesday seeing the strongest winds. Peak gusts will be
30-35 miles per hour today and close to 40 miles per hour on Wednesday when the winds
aloft will be strongest. Generally expect dry conditions today and
again Wednesday. However, there will be some moisture over Mineral
County Wednesday for the threat of thunderstorms.
The upper low begins to move inland Wednesday night into Thursday.
For Wednesday night, the models differ on exactly how much
moisture and instability will be present over western Nevada ahead
of it. The NAM is quite unstable in the middle-levels with 250 j/kg
of cape and little cin from a parcel at 600 mb. It generates
showers/storms around the Highway 95 corridor in western Nevada.
However, the GFS has a cap above the moist layer and is dry. The
ec is also dry and the sref shows little support for the NAM. Will
keep the forecast as is with the only showers in western Lassen
County closer to the upper low and in central Nevada well east of
The differences continue Thursday with the GFS/ec/sref hitting
northeast California/northwest Nevada harder with precipitation chances and
keeping it dry south of I-80. The NAM is the opposite with some
light rain Thursday evening in the deformation of a better
deformed low across Mono-Mineral counties. Will continue with the
model consensus and increase the chance of rain in northeast
California slightly, but maintain the threat just about everywhere
due to the uncertainty. Any precipitation amounts look to be light at
this time. Temperatures will cool back to near normal Thursday
with the cloud cover and cooling aloft. Wallmann
Long term...Friday through Monday...
the GFS has finally trended farther west with the cutoff low which
develops from incoming trough. However, the GFS along with the
European model (ecmwf) have trended that low farther south as well which would
result in less impact on weather for our area this weekend. The
Gem remained farther north and thus keeps confidence in the
forecast medium at best. So few changes were made to the ongoing
forecast this morning. Thunderstorm chances were confined to far
southern areas Friday-sun with all areas dry Monday. If the European model (ecmwf) is
correct, thunderstorms will be needed Monday as the low lifts
northeastward. The GFS/Gem are not indicating this. Temperatures
will warm slowly through the period. On a positive note, a general
east-southeast flow will prevail with thermal trough over California for
at least the Friday-sun period. This would greatly mitigate the smoke
issues along the eastern Sierra and western Nevada. Hohmann
smoke from the King fire will continue to be the main issue for
the next several days as surface flow remains southwest to west.
As long as the fire remains active, expect smoke to envelop much
of northeast California and far western Nevada generally north of Highway 50
today and Wednesday with smoke shifting a bit southward Thursday
as winds turn more westerly behind front. Terrain obscurement is
likely during the peak smoke period in the afternoon and early
evening with visibility 3-5sm, locally lower. Gusty winds are
expected both today and Wednesday with gusts 25-30kt today and
30-35kt Wednesday ahead of main trough. Hohmann
For more information from the National Weather Service visit...
http://weather.Gov/Reno (all lower case)