High Wind in Nevada, February 2, 2020

Area Forecast Discussion
National Weather Service Reno NV
258 AM PST Sun Feb 2 2020

.SYNOPSIS...

A strong cold front today will bring gusty winds and much colder
conditions through early this week. A burst of snow along the
front may create slick roads today as well. A slow warming trend
begins on Wednesday.

&&

.SHORT TERM...Through Tuesday.

The well advertised cold front that will move through the region
today is currently, as of 2 am, moving into northwest California.
Winds continue to increase along ridges with gusts currently up to
50-60 mph. Temperatures in the low valleys of western Nevada
remaining extremely warm this morning with many areas still in the
50s. In case you missed it, Reno shattered it's record temperature
of 66 degrees for February 1st by 7 degrees, maxing out at 73
yesterday! This is substantial since official temperature records in
Reno go back to 1893.

Still no real changes in the forecast thinking overnight. The very
strong cold front will move through NE California and far NW Nevada
this morning, reaching the Reno/Tahoe area during the mid to late
afternoon, making it down to Mono/Mineral counties by this evening.

Winds will increase throughout the region this morning and during
the day with the strongest winds still expected in Mono/Mineral
counties where wind advisories are in place. A burst of stronger
winds is expected right along the front with brief gusts to around
50 mph possible. Winds will stay pretty breezy on Monday, especially
in west-central Nevada as pressure gradient remain tight behind the
cold front. There are some fire weather concerns with the strong
winds, see the fire weather discussion below.

Quick shot of heavy snow is expected along the front. The best
forcing is expected in central and eastern Nevada, but a quick shot
of an inch or two of snow is possible throughout western Nevada and
the Sierra. The timing of the front has slowed a little bit which
does give a better chance for some lower valleys in western Nevada
to see accumulation, but at the same time models have trended even
drier with the front the last few days. Some slick roads can be
expected along with an hour or two of very low visibility,
especially in the foothills. For lower valleys the threat may be
more of a flash freeze as snow melts on warm roadways. However
with forecast precipitation amounts in the 0.05-0.10 range
predictability remains low since moisture could quickly evaporate.
If you are driving home after a large social event today and you
see shiny roads, expect slippery conditions.

Temperatures may have already reached their max today for most areas
except west-central Nevada where the cold front will arrive later in
the day. A fairly extreme temperature change is expected with
daytime high temperatures that were in the 60s and 70s yesterday to
the 20s and low 30s by Monday. Yes, that's going to be the high
temperature Monday. With the wind and dry cold air it is going to
feel very cold. By Monday night low temperatures are going to be in
the teens and single digits with sub-zero temperatures possible in
the colder valleys, especially if enough snow falls to cover the
ground sufficiently. -Zach

.LONG TERM...Wednesday through Sunday...

High pressure aloft begins to build into the Great Basin from the
west Wednesday, bringing daytime temperatures back up near average
(mid to upper 40s) with lighter winds expected overall. The position
of the high pressure ridge axis to the west should keep gusty
northeast winds going across Sierra ridges through Wednesday,
then dropping off on Thursday.

There is a slight chance for showers for far northern Washoe and
Pershing Counties Wednesday as an impulse moves into eastern Nevada.
Otherwise, dry conditions with light winds look to prevail for
most of next week across the Sierra and western Nevada. Inversions
will strengthen in valleys leading to decreasing ventilation.

Another 'slider' type system could impact the region next weekend.
This looks like another system without much moisture, but could
bring another round of gusty winds along with aviation and fire
concerns, abrupt cooling, and a burst of snowfall along with
travel concerns. JCM

&&

.AVIATION...

Wind gusts on Sierra ridges are currently in the 40-55 kt range
and will increase to the 55-75 kt range this morning. These ridge
winds will lead to strong wind shear east of the Sierra crest
through most of today.

A cold front will move out of Oregon into northern CA/NV early this
morning and then sweep southward across the Sierra and western NV
today. This cold front passage will bring an abrupt shift in
winds to the north along with a period of snow showers. Runways at
KRNO/KCXP/KMEV are expected to be warm enough this afternoon such
that an inch of snow could briefly accumulate but then melt. An
inch or two could accumulate and stay at KTRK, KTVL and KMMH. The
front is expected to reach KMMH after 00Z. Any precipitation that
remains on area runways/exposed surfaces past sundown will be
subject to icing as temperatures fall below freezing.

Gusty north to northeast flow will persist tonight through early
next week as the trough slowly pulls away. So turbulence
increasing today will likely persist into early this week. JCM

&&

.FIRE WEATHER...

A very dry airmass remains in place today while a cold front crosses
the region from north to south. Strong ridgetop winds have developed
this morning (peak gusts at mountain top level over 60 mph) and will
increase as the cold front approaches (peak mountain top gusts over
80 mph). Ahead of the front southwest winds will develop in valleys
today as well as humidity drops to unseasonably dry levels. The
worst fire weather conditions will be south of Bridgeport along
Highway 395 through Mammoth Lakes where single digit humidity and
wind gusts in excess of 50 mph will enhance fire danger for a 2-4
hour window this afternoon. Some light precipitation and higher
humidity arrives Sunday evening, but gusty north winds will
persist into Monday. JCM

&&

.REV Watches/Warnings/Advisories...
NV...Lake Wind Advisory from 10 AM this morning to 7 PM PST this
     evening for Pyramid Lake in NVZ004.

     Wind Advisory from 10 AM this morning to 4 AM PST Monday NVZ001.

     Lake Wind Advisory until 7 PM PST this evening for Lake Tahoe in
     NVZ002.

CA...Wind Advisory from 10 AM this morning to 4 AM PST Monday CAZ073.

     Lake Wind Advisory until 7 PM PST this evening for Lake Tahoe in
     CAZ072.

&&

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