Area Forecast Discussion
Issued by NWS Reno, NV

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000
FXUS65 KREV 110959
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
259 AM PDT Wed Oct 11 2017

.SYNOPSIS...

Temperatures will begin cooling today as a cold front moves into
northeast California and western Nevada, with below average
temperatures Thursday through Saturday with a trough over the
West. Strong easterly winds are possible over Sierra ridges Friday
night and Saturday as high pressure builds into the Great Basin.
Warmer temperatures and dry conditions are expected next week.

&&

.SHORT TERM...

Winds over the Sierra ridges have finally begun to increase in the
past few hours as a cold front approaches from far northern
California and extreme northwestern Nevada. Winds over the
northern and central Sierra crest are currently gusting 55-65
mph, and could reach 75 to locally as high as 85 mph this morning.
Regarding the advisory for Lake Tahoe, winds through late last
evening had been slow to pick up as we awaited the ridge winds to
increase. Now that the ridge winds are increasing, the JPL buoys
have been seeing a bump in wind speeds and are currently in the
15-25 mph range. Therefore, the lake wind advisory is now on
track...and has been extended through most of the morning as
simulations do not begin tapering off ridge winds until late
morning.

Cooler air begins filtering in today, settling over the region on
Thursday as a surface high builds into northern California and
Nevada. Highs will top out 10-15 degrees below average on Thursday.

Friday, a disturbance moving through the larger-scale upper
trough over the West will brush by over far northern Nevada,
possibly bringing a few showers north of Gerlach. Snow showers are
even possible over far northern Washoe County above 5000-5500
feet, with very light accumulations (less than 1 inch) possible
Friday evening. Elsewhere, the disturbance is not expected to
bring any precipitation. However, it will bring a reinforcing shot
of cool air to the region as a surface high builds into the
western Great Basin. With the high building in, strong easterly
winds will be possible over Sierra ridges, especially for exposed
ridges at the immediate Sierra crest where gusts over 70 mph are
possible by early Saturday morning. -Snyder

.LONG TERM...Saturday into next week...
It looks to be relatively quiet during this period as the last short
wave moves out Saturday followed by low amplitude ridging. The model
suite is in good agreement so high confidence in a period of dry
weather with relatively light winds.

Saturday will be the coldest day behind the front with northeast
winds. Temperatures will be a good 10 degrees below average. As
the ridge builds and the flow aloft becomes more west to southwest,
temperatures will warm into early next week. Still, with a lower
October sun angle, the winds aloft are not strong enough for good
mixing. Weak to moderate valley inversions will remain so valley
temps will only rise back to near average. Mountain temps will see
more warming and be 5 to 10 degrees above average. This results
in highs around 70 in the valleys and 60s mountains. Overnight
lows will be cool under clear skies.

Then attention turns to an atmospheric river system for late next
week. High confidence in a potent system moving into the West Coast,
but the impacts here are still in question. Moderate to high
confidence we will see some type of wind event. Confidence in any
precipitation remains low as most ensemble members keep it a brush-
by with most precip into OR/WA. We will continue to monitor this
system. Wallmann

&&

.AVIATION...
VFR conditions through Thursday. Locally gusty winds this morning
with area terminals gusting to 20 kts near the Sierra. Some LLWS
near Lake Tahoe due to wind channeling and ridge winds gusting to 60-
70 kts. LLWS expected to diminish after 18Z due to better mixing and
winds aloft weakening. Winds diminish overnight tonight, but more
gusts to 20-25 kts possible Thursday afternoon as another cold
front approaches. Wallmann

&&

.REV Watches/Warnings/Advisories...
NV...Lake Wind Advisory until 11 AM PDT this morning for Lake Tahoe
     in NVZ002.

CA...Lake Wind Advisory until 11 AM PDT this morning for Lake Tahoe
     in CAZ072.

&&

$$

For more information from the National Weather Service visit...
http://weather.gov/reno



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