Area Forecast Discussion
Issued by NWS Reno, NV

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FXUS65 KREV 160913

Area Forecast Discussion
National Weather Service Reno NV
213 AM PDT Mon Oct 16 2017

A warming trend will start today as high pressure strengthens over
the Sierra and western Nevada. Valley inversions will remain across
the region today with potential for better mixing by Tuesday. Winds
will become gusty ahead of an incoming storm Thursday and Thursday
night. Cooler conditions with valley rain and mountain snow are on
tap for the end of the work week.


Area of high pressure builds across the Sierra and western Nevada
today, which will reinforce inversions and keep colder air trapped
in the valleys for today. There will be some warming, especially
along the mid slopes and ridgelines, but valleys will be slower to
warm due to the inversions.

High pressure will persist through Wednesday with generally light
winds and warmer temperatures. The ridge does weaken on Wednesday in
advance of the approaching trough. For Tuesday and Wednesday
although winds will be fairly light, the mixing should be quite a
bit better with the potential for afternoon wind gusts around 20

Areas of smoke and haze still pose a problem through the week,
especially with westerly flow in place across the region. The extent
of the smoke/haze will be largely determined by fire activity and
the generally weak transport winds. If you are unsure of the air
quality you can always go to -Edan

.LONG TERM...Thursday through next week...
A few changes this run for the late week system as the models have
now reversed from earlier runs with the cut-off low being absorbed.
The models now have it shearing apart before the main system arrives
and therefore little moisture is drawn up from the subtropics. As a
result, the incoming system is quite a bit drier than previous runs,
especially for areas south of Highway 50. The system is also a bit
slower overall.

Thursday still looks to have some winds, but not as strong as
believed previously with the slower timing. Gusts of up to 35 mph
are possible during the afternoon, and with moisture much less
than previous runs, fire weather issues are there at least south
of I-80. Winds are now stronger overnight Thursday night with a
brief downslope signature setting up. That said, it develops so
quickly with moisture quickly moving in that it does not look like
a big event. Higher gusts in the foothills, ridges and mid slopes
are likely. Still, if the models go back to showing the moisture
entrained from the upper low, this won`t happen.

For precip, kept the precip chance generally the same near and north
of highway 50, but went a little lower south of there based on the
latest guidance. I didn`t want to make too many adjustment given
recent changes in the models. QPF does look a bit lower as well and
adjusted that downward. If the current trends hold, perhaps up to an
inch along the Sierra Crest from Tahoe northward with values
dropping off rather rapidly to the east. For Mono County, perhaps a
1/4" of liquid from the storm. Snow levels are similar, starting
near 9-10000 feet and falling to 6-7000 on the back side.

Ridging builds in rapidly for the weekend with lighter winds and
temps rising above normal next week. This ridge will hold through at
least next week and high confidence that the rest of October will be
drier than average.


VFR conditions through Wednesday with generally light winds. Winds
on the ridge do increase Tuesday and Wednesday, but still only up to
20 kts. Winds increase Thursday ahead of the next system with gusty
winds, rain and high elevation snow late Thursday night through
Friday morning. Some LLWS is possible Thursday night, with
confidence about 60% that at least one terminal in the Reno-Tahoe
area will be impacted.


.REV Watches/Warnings/Advisories...


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