Winter Weather Advisory 7, NWS Reno, NV

Area Forecast Discussion...UPDATED
National Weather Service Reno NV
1214 PM PST Tue Feb 2 2021

.UPDATE...

We are making some adjustments to the Winter Weather advisories
and also issuing some wind-related advisories based on the latest
trend for the weather system affecting our region:

* Lassen County: Shifting the start time of Winter Wx Advisory to
  5 pm this evening, lowering to 5000 ft elevation. We're focusing
  more on the next snow area developing this evening mainly north
  of Susanville with some cooler air arriving. Wet roads through
  the rest of today possibly become icy tonight, with a few
  inches of new snow falling on top.

* Tahoe: We're keeping the Winter Wx Advisory but shifting the
  focus to near the Sierra crest (2-6" for 7000+ foot elevation)
  with only minimal snowfall (0-2" down to lake level). We'll be
  ending this advisory a few hours sooner (Midnight tonight) then
  attach a Lake Wind Advisory for Tahoe after midnight into
  Wednesday, as continued gusty ridge winds will likely mix down
  to the lake especially late tonight through Wednesday morning.

* Mono County: Cancel Winter Wx Advisory for Mono County as the
  precip band is likely to weaken enough to limit snow amounts as
  it slowly drifts south. We will issue a Wind Advisory though for
  late tonight through Wednesday, as high resolution guidance is
  indicating a short period of enhanced winds for the Sierra and
  wind prone areas of US-395 especially for the overnight through
  mid-morning hours. MJD

&&

.PREVIOUS DISCUSSION... /Issued 239 AM PST Tue Feb 2 2021/

SYNOPSIS...

A storm system will bring moderate snow amounts and difficult travel
conditions to the Sierra today, along with gusty winds. Lower
elevations of eastern California and western Nevada will see mainly
light rain which may end with a rain and snow mix. A few additional
showers are expected Wednesday before a drier pattern results the
remainder of the week and into the weekend. Temperatures to
remain near to below normal.

SHORT TERM...

The moisture tap associated with our next system is streaming across
northern CA, but retains it's very slow eastward translation as the
main system elongates and splits off the coast. We are seeing
rain/snow falling around Bogard CA and reaching as far east as the
Hwys 36/44 region. However, latest high resolution guidance is
keeping the main snow impacts from reaching the Tahoe Basin until
daybreak into mid-morning. Heaviest precipitation rates for
northeast California and the Sierra from the Tahoe Basin north are
likely from this morning through mid-afternoon before tapering
off to showers.

Winds are rather blustery across ridgelines this morning, with gusts
in the 70-90 mph range. Some wind is mixing down to the surface
as well with gusts in the 25-35 mph range and a few wind prone
locations reaching 40-50 mph as of the time of writing. Winds may
further reduce visibility over Sierra passes with blowing snow
possible. Gusty conditions will continue into Wednesday with winds
becoming lighter and turning north and then east by Thursday.

The southern branch of the split trough is no longer progged to move
inland, becoming a cutoff low in the eastern Pacific. With less
appreciable forcing to the south, precipitation amounts are going to
be rather meager through much of Mono County and the eastern Sierra.
Anticipate the highest totals in northern Mono and Alpine Counties,
but even here, the 5-10" of potential accumulation in the high
Sierra will seem like nothing after the feet of snow that fell
last week. Snow should reach the region this afternoon and
evening. Farther south, toward Mammoth, ensembles are now hardly
showing any accumulation. Anticipate several inches for the
mountain, but a sharp drop off to the east, with hardly anything
near US-395.

A cold front passing through the region this afternoon and tonight
will provide the best chances for rain/snow into western Nevada.
However, this will be a quick shot and there isn't much moisture to
work with, so we aren't anticipating much in the way of liquid
totals. In addition, coverage will be rather spotty.

A secondary upper wave will bring another round of showers to the
region Wednesday along with further cooling. Liquid amounts are
going to be minimal and spotty, but we all know it doesn't take much
snow to cause travel difficulties. -Dawn

LONG TERM...Friday and beyond...

Medium range deterministic models (GFS, EC) and their ensembles show
continuity early on as a deep cold trough affects much of the
nations midsection with a ridge upstream centered just off the west
coast. This will result in generally quiet weather and seasonal
temperatures for late week and the weekend. Brisk north winds aloft
Friday will gradually wane this weekend as the trough shifts east.
So the gusty northeast ridge winds across the Sierra Friday-Friday
night will diminish Sat-Sun. Also temperatures could warm slightly
going into the weekend although light winds/limited mixing will keep
weak-moderate valley inversions in place which will limit the amount
of warming.

Beyond this weekend, models have trended less amplified with the
West Coast ridge and the eastern U.S. trough. This scenario was
showing in the cluster analysis yesterday and continued to be
supported by a couple of the ensemble clusters this morning. This
would support milder systems coming in off the Pacific. Timing of
systems in this pattern and this far out renders confidence in the
forecast low. Both the deterministic GFS/EC (00Z) indicate a
shortwave moving across CA/NV the early to middle part of next week.
However, the national blended model has not picked up on this
feature yet. So we will have to watch for another model cycle or two
for confirmation on precipitation potential given the rather large
change in the past 24 hours. If it does occur, it would be snow in
the mountains with rain/snow for lower elevations. The gridded
forecast is dry Mon-Tue night. However, if you have outdoor plans,
be prepared for possible changes in the forecast sometime in the
next day or two. Hohmann

AVIATION...

South to southwest FL100 winds are sustained around 45-55 kts this
morning, leading to turbulence and wind shear. Winds are surfacing
at terminal sites that favor southerly directions, including KRNO,
KMEV, KTRK, and KTVL with gusts of 25-30 kts being reported as of
the time of writing. Winds will remain elevated through the day
and into Wednesday as our winter system moves through the region.

This storm is bringing terrain obscuration with lowered cigs/vis and
rain/snow. Here are the highlights for terminal sites:

KTVL/KTRK: 14z Tue - 06z Wed, peak rates 18-00z. Starting as rain
or a mix, turning to snow by mid-late afternoon. 1-4" potential
accumulation.

KMMH: 06z-14z Wed, very light with accumulation under 1". Should be
all snow.

KRNO/KCXP/KMEV: Spotty light rain showers this afternoon and
evening. Less than a 10% chance or any snow accumulation.

A secondary feature on Wednesday will bring another round of showers
with light snow possible for all elevations. Coverage will be spotty
and accumulation potential looks minimal--under 1 inch at most for
terminals. -Dawn

&&

.REV Watches/Warnings/Advisories...
NV...Lake Wind Advisory from midnight tonight to 4 PM PST
     Wednesday for Lake Tahoe in NVZ002.

     Winter Weather Advisory until midnight PST tonight NVZ002.

CA...Winter Weather Advisory from 5 PM this afternoon to 4 AM PST
     Wednesday above 5000 feet in CAZ071.

     Wind Advisory from 10 PM this evening to 4 PM PST Wednesday
     CAZ073.

     Lake Wind Advisory from midnight tonight to 4 PM PST Wednesday
     for Lake Tahoe in CAZ072.

     Winter Weather Advisory until midnight PST tonight CAZ072.

&&

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RENO NV
914 AM PST TUE FEB 2 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0340 PM     NON-TSTM WND GST 1 WNW FLORISTON         39.40N 120.03W
02/01/2021  M59 MPH          NEVADA             CA   MESONET

            MESONET STATION LIB21 WSH201-FLORISTON.

0440 AM     NON-TSTM WND GST 1 ENE PAYNESVILLE       38.82N 119.78W
02/02/2021  M58 MPH          ALPINE             CA   MESONET

            MESONET STATION LIB25 MULLER1296-EMIGRANT
            TRAIL.

0650 AM     NON-TSTM WND GST 4 NNW WASHOE CITY       39.38N 119.83W
02/02/2021  M57 MPH          WASHOE             NV   MESONET

            MESONET STATION GALN2 GALENA.

1133 PM     NON-TSTM WND GST 4 WNW TRUCKEE           39.34N 120.27W
02/01/2021  M57 MPH          NEVADA             CA   MESONET

            MESONET STATION TADC1 TAHOE DONNER.

0230 AM     NON-TSTM WND GST 5 SSE SIERRAVILLE       39.52N 120.33W
02/02/2021  M56 MPH          SIERRA             CA   MESONET

            MESONET STATION RNYC1 RICE CANYON.

0353 PM     NON-TSTM WND GST 17 S PITTVILLE          40.81N 121.30W
02/01/2021  M56 MPH          LASSEN             CA   MESONET

            MESONET STATION LDRC1 LADDER BUTTE.

0320 AM     NON-TSTM WND GST 1 SW CONWAY SUMMIT      38.08N 119.20W
02/02/2021  M55 MPH          MONO               CA   MESONET

            MESONET STATION SE089 1.3 SW CONWAY SUMMIT
            (SCE).

0338 PM     NON-TSTM WND GST 4 E INCLINE VILLAGE     39.24N 119.88W
02/01/2021  M54 MPH          WASHOE             NV   MESONET

            MESONET STATION LVYN2 LITTLE VALLEY.

1011 PM     NON-TSTM WND GST 3 N DOYLE               40.06N 120.09W
02/01/2021  M52 MPH          LASSEN             CA   MESONET

            MESONET STATION DYLC1 DOYLE.

0709 PM     NON-TSTM WND GST 3 WSW MEYERS            38.84N 120.06W
02/01/2021  M51 MPH          EL DORADO          CA   MESONET

            MESONET STATION FW4812 ECHO LAKE.

1250 AM     NON-TSTM WND GST 1 S BODIE               38.20N 119.01W
02/02/2021  M49 MPH          MONO               CA   MESONET

            MESONET STATION SE749 SCE BODIE STATE PARK.

0550 AM     NON-TSTM WND GST 3 NW WASHOE CITY        39.35N 119.86W
02/02/2021  M48 MPH          WASHOE             NV   MESONET

            MESONET STATION NV016 MT ROSE HIGHWAY.

0748 PM     NON-TSTM WND GST 3 E COLEVILLE           38.57N 119.46W
02/01/2021  M48 MPH          MONO               CA   MESONET

            MESONET STATION WALC1 WALKER.

0458 AM     NON-TSTM WND GST 4 NNW LAKEVIEW          39.26N 119.83W
02/02/2021  M47 MPH          WASHOE             NV   MESONET

            MESONET STATION SRNNV 3.7 NW LAKEVIEW (NV
            DOT).

0310 AM     NON-TSTM WND GST 3 N FLORISTON           39.45N 120.01W
02/02/2021  M47 MPH          SIERRA             CA   MESONET

            MESONET STATION LIB15 WASHOE204-FARIAD.

0655 AM     NON-TSTM WND GST 3 SSW SPARKS            39.50N 119.77W
02/02/2021  M46 MPH          WASHOE             NV   ASOS

            ASOS STATION KRNO RENO.

0340 AM     NON-TSTM WND GST 1 SW WASHOE CITY        39.31N 119.83W
02/02/2021  M46 MPH          WASHOE             NV   MESONET

            MESONET STATION WSVNV 1.3 SW WASHOE CITY (NV
            DOT).

0215 AM     NON-TSTM WND GST 7 WSW STANDISH          40.32N 120.53W
02/02/2021  M46 MPH          LASSEN             CA   MESONET

            MESONET STATION DW5697 JANESVILLE.

1010 PM     NON-TSTM WND GST 3 SE EMERALD BAY        38.93N 120.05W
02/01/2021  M46 MPH          EL DORADO          CA   MESONET

            MESONET STATION LIB18 MEY3400-CAMP
            RICHARDSON.

0531 AM     NON-TSTM WND GST 1 S JOHNSON LANE        39.04N 119.72W
02/02/2021  M44 MPH          DOUGLAS            NV   MESONET

            MESONET STATION AS061 MINDEN.

0205 AM     NON-TSTM WND GST 4 SE SAND MOUNTAIN      39.27N 118.35W
02/02/2021  M43 MPH          CHURCHILL          NV   MESONET

            MESONET STATION SSPNV 3.7 SE SAND MOUNTAIN
            (NV DOT).

0200 PM     NON-TSTM WND GST 4 SSE PITTVILLE         41.00N 121.29W
02/01/2021  M43 MPH          LASSEN             CA   MESONET

            MESONET STATION PG144 3.8 SE PITTVILLE
            (PGE).

0644 AM     NON-TSTM WND GST 2 SSE DOYLE             40.00N 120.09W
02/02/2021  M42 MPH          LASSEN             CA   MESONET

            MESONET STATION CF088 1.5 SE DOYLE
            (CALTRANS).

0456 AM     NON-TSTM WND GST 2 NNE WASHOE CITY       39.35N 119.79W
02/02/2021  M42 MPH          WASHOE             NV   MESONET

            MESONET STATION GLCNV 2.3 NE WASHOE CITY (NV
            DOT).

1219 AM     NON-TSTM WND GST 1 WNW HOMEWOOD          39.08N 120.17W
02/02/2021  M42 MPH          PLACER             CA   MESONET

            MESONET STATION HMDC1 HOMEWOOD.

0755 AM     NON-TSTM WND GST 2 NE MINDEN             38.98N 119.75W
02/02/2021  M41 MPH          DOUGLAS            NV   AWOS

            AWOS STATION KMEV MINDEN.

0539 AM     NON-TSTM WND GST 3 ESE LAKE CITY         41.62N 120.16W
02/02/2021  M41 MPH          MODOC              CA   MESONET

            MESONET STATION SSYC1 SURPRISE VALLEY.

0253 AM     NON-TSTM WND GST 3 N MEYERS              38.90N 120.00W
02/02/2021  M41 MPH          EL DORADO          CA   ASOS

            ASOS STATION KTVL SOUTH LAKE TAHOE AP.

0900 PM     NON-TSTM WND GST 1 NNW TWIN LAKES        38.16N 119.35W
02/01/2021  M41 MPH          MONO               CA   MESONET

            MESONET STATION SE410 0.7 NW TWIN LAKES
            (SCE).

0435 PM     NON-TSTM WND GST 2 N STEAD               39.67N 119.88W
02/01/2021  M41 MPH          WASHOE             NV   AWOS

            AWOS STATION KRTS RENO STEAD.

0210 PM     NON-TSTM WND GST 2 ENE PITTVILLE         41.06N 121.28W
02/01/2021  M41 MPH          LASSEN             CA   MESONET

            MESONET STATION PG644 OLD HIGHWAY ROAD.

&&