Area Forecast Discussion
Issued by NWS Reno, NV

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FXUS65 KREV 162107
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
207 PM PDT Mon Oct 16 2017

.SYNOPSIS...
Hazy conditions will continue through Tuesday morning followed by
some improvement later in the day. Otherwise, dry and warm
conditions are expected through midweek. A fast moving and weak
storm system will bring increased winds Thursday, followed by a
short period of light rain and high elevation snow Thursday night
into Friday. Next weekend looks dry with a warming trend again.

&&

.SHORT TERM...

The primary weather issue through midweek will be the presence of
haze from northern CA fires, mainly through Tuesday morning when
the inversions associated with the ridge axis overhead will be
stronger. Later Tuesday through Wednesday, improved haze
dispersion should occur as the ridge axis pushes east with the
inversion weakening, leading to higher mixing heights and more
favorable ventilation. This assumes that the Table fire (west of
the Sierra crest and southwest of Tahoe) does not show a
significant increase in activity during the daytime hours. For the
latest air quality information, go to www.airnow.gov.

Otherwise, dry and warm conditions (with areas of cirrus mainly
through Tuesday) will prevail through Wednesday with highs in the
70s to near 80 degrees for lower elevations and mid 60s-lower 70s
for Sierra valleys. Surface winds will generally be light
although prevailing direction switches to the southwest or west,
while ridge top winds increase a bit on Tuesday in response to a
weak shortwave passage across the northwest US-southwest Canada
border.

By Thursday, winds will begin to increase in advance of a trough
approaching the west coast, while temperatures remain above
average. Wind gusts in the afternoon may reach the 30-40 mph
range from Reno-Carson northward, with Sierra ridge gusts around
60 mph. Stronger winds are expected Thursday night. Precipitation
is becoming less likely through the afternoon hours as the
moisture feed is now only projected to reach the northwest CA
coast by that time. MJD

.LONG TERM...Thursday night and beyond...

The fast moving trough accompanied by a narrow band of Pacific
moisture will bring gusty winds and a short period of
precipitation Thursday night into Friday, with Friday`s high
temperatures about 15 degrees cooler than Thursday. Latest trends
favor more wind and less overall rain and snow, as the moisture
feed weakens rather quickly as it reaches the Sierra. Wind gusts
could peak in the 40-50 mph range across northwest NV and along
the Sierra front of western NV, with potential for Sierra ridge
gusts 80+ mph Thursday night/early Friday.

We have reduced precip potential to between 0.25 and 0.50 inch
for northeast CA, Tahoe basin, and near the Sierra crest (mainly
north of Tioga Pass) with lighter amounts elsewhere. Some portions
of west central NV especially south of US-50 and eastern Mono
County could end up with no rain from this trough passage. A few
inches of snow could accumulate mainly above 7500 feet, but travel
impacts are likely to be limited to higher passes for only a
short duration.

After brisk and chilly conditions Friday, flat ridge will begin to
rebuild Saturday. A shortwave moving across the Pacific Northwest
may bring some very light warm advection showers to areas near the
Oregon border, but the main effect will be mid-high level cloud
cover mainly north of I-80. Temperatures will begin their upward
climb, although far north areas may not see a very significant
warmup due to this thicker cloud shield.

Then from Sunday into early next week, above average temperatures
will return with light winds and little to no cloud cover as ridge
of high pressure rebuilds overhead. The warm temperatures could
continue through much of next week, although some of medium range
guidance is trending toward drifting the ridge axis westward to
the eastern Pacific, which which may open the door for a back
door cold front passage by mid-late next week. MJD

.AVIATION...

VFR conditions through Wednesday with generally light surface
winds. Haze may produce some reductions to slantwise visibility
through Tuesday morning, with haze decreasing later Tuesday. Ridge
winds increase briefly Tuesday with gusts 30-40 kt, but the more
significant wind increase is expected late Thursday into early
Friday, producing turbulent conditions. LLWS is also possible at
times at some of the terminals Thursday night. Light rain and high
elevation snow is also expected but at this time significant
impacts to the main terminals due to precip are less likely. MJD

&&

.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

$$

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



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