Area Forecast Discussion
Issued by NWS Reno, NV

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FXUS65 KREV 172110

Area Forecast Discussion
National Weather Service Reno NV
210 PM PDT Sun Sep 17 2017


Seasonable temperatures and dry conditions will prevail through
Monday. A series of cold fronts will produce gusty winds on Monday
and again Wednesday. Below average temperatures are expected from
Tuesday through early next weekend, with potential for freezing
temperatures in some colder lower valleys. Light showers are
possible at times from Wednesday through Friday.



Stronger winds are on tap for Monday as low pressure moves into
the Pacific Northwest. Surface wind gusts on Monday are projected
to range from 35-45 mph, with Sierra ridge gusts to 75-85 mph.
Fire Weather concerns will be increased with these stronger winds
--see the Fire Weather segment below for more details.

Most of the forcing and deep moisture associated with this storm
system will remain north of the Oregon border for the next few
days. A few very light sprinkles (measurable rain unlikely) may
brush across parts of northwest NV Monday night behind the surface
cold front. Isolated showers are also possible Tuesday night and
Wednesday morning in far northeast CA and northwest NV ahead of
the next shortwave trough and reinforcing cold front.

Temperatures near seasonal averages today will start to drop on
Monday, especially north of I-80. By Tuesday and Wednesday,
cooler temperatures filter into most areas with highs mainly in
the upper 60s to mid 70s for lower elevations, except 60s north
of Susanville-Gerlach and near the Sierra.

One thing of note will be the DRASTIC CHANGE IN WIND CHILLS BY
WEDNESDAY NIGHT with the strong cold front. This will be especially
noticeable in higher elevations and on exposed ridges with wind
chills possibly below 20 degrees. Hikers and campers should take
precautions to not get caught out in the wind in the high Sierra
starting Wednesday night. Snyder/MJD

.LONG TERM...Thursday through Sunday...

The main change to the long term was to lower highs a few more
degrees for most areas, mainly through Friday.

Northeast California and western Nevada will remain under a
large-scale trough late-week through next weekend. This is
expected to keep high temperatures below to well below average.
As far as precipitation, there will be nebulous chances for
showers late in the week as some simulations indicate addition
waves dropping overhead as the region remains under northerly flow
aloft. At this time, precipitation looks to remain light at best
but could certainly coat the higher Sierra in a light dusting of
snow from time to time, especially if snow showers occur overnight.



A cold front will approach northeast CA Monday afternoon and
western NV Monday night and early Tuesday. Gusty surface winds
develop by midday with areas north of I-80 seeing gusts around 30-35
kts. Sierra ridge gusts are likely to top 50-65 kt so turbulence
and pockets of LLWS, especially in channeled terrain (such as
KTVL), are likely for Monday. There is a small chance for a few
very light showers north of a line from Susanville to Gerlach by
Monday night but they are unlikely to substantially restrict

The chances for showers increase from late Tuesday into Wednesday as
another front makes its way south. This one is likely to bring even
stronger winds to the region for the Wednesday/Wednesday night time
frame with gusts approaching 35-40 kt in the valleys and better than
65 kt at the ridges. Snyder/??



Winds gusting 30-45 mph will combine with lower RH to create
critical fire weather conditions for much of Western Nevada and a
small portion of northeastern California on Monday (zones 278,
450, 453, & southern 458). Relative humidity will generally be
12-24% from eastern Lassen County into the Basin and Range. While
values over 15% strictly do not reach critical thresholds, the
strength of the wind will easily compensate allowing for fast
rates of fire spread through area grasses and brush. These
conditions will occur from late Monday morning into Monday
evening. Otherwise, RH will be too high in the Sierra (zones 270,
271, 272 & northern 458) while winds will be too low in
Mono/Mineral Counties (zones 273 & 459) to warrant a Red Flag

A more brief window of critical conditions is possible Wednesday
as winds will be even stronger. However, RH will increase more
quickly than Monday. With confidence on the lower end, no fire
weather products have been issued for Wednesday yet. Boyd


.REV Watches/Warnings/Advisories...
NV...Red Flag Warning from 11 AM to 10 PM PDT Monday NVZ450-453-458.

     Lake Wind Advisory from 10 AM to 10 PM PDT Monday for Lake Tahoe
     in NVZ002.

     Lake Wind Advisory from noon to 10 PM PDT Monday for Pyramid
     Lake in NVZ004.

CA...Red Flag Warning from 11 AM to 10 PM PDT Monday CAZ278.

     Lake Wind Advisory from 10 AM to 10 PM PDT Monday for Lake Tahoe
     in CAZ072.



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