Strong Wind in Nevada, September 16, 2019

Area Forecast Discussion
National Weather Service Reno NV
329 PM PDT Mon Sep 16 2019

.SYNOPSIS...

Rain and high elevation snow showers behind a strong cold front
will continue over portions of the eastern Sierra and western
Nevada through this evening. Frosts and freezes are possible in
outlying lower elevation areas, with freezes expected for Sierra
valleys. Another storm system is possible Wednesday into Thursday
with more showers and breezy winds.

&&

.SHORT TERM...

A strong cold front is slowly moving across northwestern Nevada
and  the eastern Sierra this afternoon. Gusty winds will continue
into the early evening hours along the US 395 corridor, especially
through Mono County. Fire weather concerns remain west central NV
east of US-95, and eastern Mono County as gusty winds and low
relative humidities remain ahead of the front. See the Fire
Weather discussion for more details. Precipitation associated with
this front will diminish over the next few hours. Spotty
convective showers are expected behind this front through this
evening, mainly for northeast CA and northwest NV.

Temperatures have dropped nearly 30 degrees across much of
northwestern Nevada and northeastern California since 1 PM PDT
yesterday afternoon. Frost and freeze concerns remain for many low
valley locations outside of population centers overnight. Freezes
are almost certain overnight for Sierra valley locations. A brief
break between weather systems will take place on Tuesday, with
high temperatures warming a few degrees. Another trough will move
over the northern portion of our area, bringing chances for rain
showers and possibly some high mountain snow. A slight chance of
thunder was added to the forecast for northeastern Washoe County
Wednesday afternoon as the ECMWF and GFS have shown more
instability ahead of the trough axis. -Johnston

.LONG TERM...

No major changes were made to the extended forecast.

For Thursday, upper low extending from the northern Rockies to the
northern Great Basin will keep temperatures well below average,
with highs mainly in the 60s for lower elevations. Cyclonic flow
around this low will keep clouds and shower chances over the region,
with the best overall chances across far northeast CA and northwest
NV. Additional precip amounts are expected to be light, generally
less than 0.10 inch.

From Friday through early next week, an upper ridge off the west
coast will bring dry conditions to the region with a steady warming
trend through Sunday. A weak shortwave brushing across the northwest
US may bring a slight increase in winds Sunday afternoon, otherwise
light winds are expected from Friday through Monday. No other
significant impacts are expected from this shortwave passage, with
highs Monday remaining similar to Sunday (lower 80s for lower
elevations, lower-mid 70s near the Sierra). MJD

&&

.AVIATION...

Winds associated with the strong cold front have subsided across
the  northern Sierra and much of northwestern Nevada. Some
residual convective showers are possible through the evening for
areas north of US-50.

Mountain wave turbulence is still possible downstream of the
central-southern Sierra Nevada this afternoon and evening as the
jet noses slowly northeast across the Great Basin and Rockies.
Winds at KMMH will continue to be gusty through at least 1900 PDT
as the pressure gradient remains strong in eastern Mono County
beneath this jet.

Showers are still possible along the eastern Sierra as the front
continues to progress eastward. Lighter winds can be expected
Tuesday before another weather system brings increased winds and
chances for precipitation Wednesday afternoon/evening. -Johnston

&&

.FIRE WEATHER...

Primary concern for critical fire weather conditions will be for
eastern portions of the warning area into early evening, where
humidity values are still in the 10-15% range. As strong winds
push across west central NV and eastern Mono County, they will
also be accompanied by a jump in humidity. Elsewhere, humidity
values have increased across most of eastern CA and western NV
through early afternoon. The cold front has also brought some
wetting rains to many locations north of Highway 50, around
0.25-0.60 inches with some sites in northeast CA receiving around
1" of rain. Snow showers were also prevalent for areas above 7500
feet, with a few inches of short- lived snow accumulations in the
higher terrain.

Another round of winds is expected for Wednesday, as the next low
pressure system approaches the Sierra and western Nevada. However,
humidity values will be higher. The winds also don't appear to be as
strong or as long lasting as this event. The cold front with this
next system isn't as organized, so while wetting rains are possible,
it may be more localized. -Edan

&&

.REV Watches/Warnings/Advisories...
NV...Red Flag Warning until 6 PM PDT this evening NVZ453-459.

     Lake Wind Advisory until 8 PM PDT this evening for Pyramid Lake
     in NVZ004.

     Lake Wind Advisory until 8 PM PDT this evening for Lake Tahoe in
     NVZ002.

     Wind Advisory until 8 PM PDT this evening NVZ001.

CA...Red Flag Warning until 6 PM PDT this evening CAZ273.

     Wind Advisory until 8 PM PDT this evening CAZ073.

     Lake Wind Advisory until 8 PM PDT this evening for Lake Tahoe in
     CAZ072.

&&

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