A trough of low pressure and its associated surface cold front moved into the Sierra Nevada from the northwest to the southeast during the evening hours of February 29th into the early morning hours of March 1st. The main impact ahead of the front on the 29th were strong gusty winds.
Every event with a place to put it; 6 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS REV wrote it up.
A trough of low pressure and its associated surface cold front moved into the Sierra Nevada from the northwest to the southeast during the evening hours of February 29th into the early morning hours of March 1st. The main impact ahead of the front on the 29th were strong gusty winds. Snow developed around sunset the 29th in northeastern California and moved south-southeast through the night.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Reno, NV wrote its last area forecast discussion before the first event at Feb 29, 3:20 AM PST, 3 hours 10 minutes earlier.
Area Forecast Discussion
National Weather Service Reno NV
320 AM PST Sat Feb 29 2020
.SYNOPSIS...
An abrupt change in the weather will be in store today through
Sunday as a strong cold front approaches the region. Strong,
gusty winds are expected this afternoon with rough lakes, gusty
cross winds and areas of blowing dust possible. The front will
result in snowfall across the Sierra and western Nevada valley
floors this evening into Sunday morning. Strong and gusty east
winds will develop across the Sierra ridgetops Sunday evening into
Monday. Drier and warmer weather is on tap next week.
&&
.SHORT TERM...
A powerful cold front makes its approach today with strong and
gusty winds expected this afternoon followed by snowfall along the
front this evening and Sunday morning.
The cold front continues to show strong dynamics which will allow
snowfall to be concentrated in a narrower band along the front
with a 2-6 hour period of snow possible. Although not a big storm
in terms of snowfall amounts, the dynamic nature of the front
will allow for a quick/sudden burst of moderate to heavy snowfall
as the front passes.
Main Updates:
* Timing of the cold front has trended a few hours faster. As
such, snow impacts along I-80 may begin as early as 5-7pm.
* Winter Weather Advisories issued across the Sierra from the
Tahoe Basin into Mono County.
* Colder temperatures forecast Sunday afternoon.
Wind:
* Increasing winds expected today with peak winds this afternoon
and evening ahead of the front. Gusts 34-45 mph most areas but
45-50+ mph possible through the Hwy 395/I-580 corridor around
Reno and Carson City and through much of Mono County.
* Wind impacts include: Hazardous boating on area lakes, strong
crosswinds for high profile vehicles, aviation turbulence, and
sudden reductions in visibility in areas of blowing dust
downwind of desert sinks and dry lake beds. The wind and our
very dry conditions will produce fire weather concerns. See the
fire section below for additional details.
Snow:
* Snowfall will be concentrated in a band along the cold front
with a 2-6 hour period of moderate to heavy snow possible.
* Western Nevada valleys could see 1-2 inches with upwards of 4
inches across foothill areas. For the Sierra, 2-5 inches for
valleys such as around Truckee and Tahoe, with 5-10 inches for
the crest (up to 12 inches along the crest in Mono County).
* Start time for snowfall will be as early as 3-4pm across
northern Lassen county and the Surprise Valley. Onset time along
the I-80 corridor across the Sierra through western Nevada
looking as early as 5-7pm with peak around 8pm-midnight. Areas
south of Highway 50 generally looking from about 3am to
mid-morning.
A few lingering upslope snow showers will be possible across Mono
County through late morning into early afternoon. Stiff north
winds will also be in place behind the front Sunday which combined
with highs in the low/mid 30s will make for some frigid conditions
with negative wind chills along mountain tops.
Another potent east wind event also looks to develop across the
Sierra ridgetops and western slopes Sunday evening into Monday
with ridge top gusts of 100-125 mph possible. Fuentes
.Long Term (Tuesday Onward)...
* Upper ridge builds in quickly but only remains for a few days this
time. Ridge will lead to quiet weather with light/variable winds
and warming temperatures. That warming could be moderated some
early in the week by any snow cover. Guidance pointing toward well
above normal readings Wednesday-Thursday and possibly Friday.
* Friday is where things start to get more interesting. Large scale
trough develops off the west coast per GFS and ECMWF ensemble
means. This increases the odds of us seeing storms of some flavor
late week into the weekend and following week. AR landfall tools
point more into SoCal, S Nevada for heavy precip risks but we're
still close enough to monitor.
* Some model differences Friday-Saturday with first potential storm.
GFS brings in a low to moderate end wind/precip deal Friday, while
ECMWF is about 24 hours later. Travel impacts from snow for the
mountain passes in each scenario. ICON keeps region dry with
storms remaining off-shore. No real preference here so have
continued chance rain/snow in mountains and area-wide strong gusty
SW winds both days. Slower ECMWF would allow for one more day
(Friday) of mild temps.
* Both ensemble systems have a good percentage of members with
another, stronger storm sometime in the March 9-11 period. Way too
soon to talk character but active weather is likely into the
second full week of March.
-Chris
&&
.Aviation...
Fast moving cold front will bring wind and snow impacts to aviation
today into Sunday.
* Wind: Widespread gusty SW winds are expected between roughly 18z-
0z today for most airports including RNO, 18z-3z for MMH. Gusts 30-
40 kts will be common, with blowing dust towards LOL/NFL. Low
level wind shear will lead things off this morning with ridgetop
flow already gusting 50-60 MPH at Alpine and Slide Mtn. Expect
rough air today, and then into tonight with a northerly wind shift
as cold front passes 3-6z this evening. Stiff N/NE winds will
continue Sunday making it feel quite chilly. High winds along
Sierra crest expected with rough air extending west of the crest
into Monday.
* Snow: High resolution simulations have sped up the onset of snow
by a few hours, more into the evening now for RNO and Tahoe
airports. Best bet now for peak snows and MVFR/IFR conditions is 4-
8z for RNO, 5-11z for TRK/TVL/CXP, and probably after 12z/Sun for
MMH. A period of light snow is also likely 6-12z overnight for
airports in W Nev including NFL/LOL. Due to rapid cooling of the
airmass and night-time frontal passage, runway accumulations and
even flash freeze of melting snow are a good bet. RNO 1-2",
TRK/CXP 2-3", TVL 3-4", and MMH 2-4" are the current projections.
Quick speed of the front is the only limiting factor to offset
decent dynamics with the front.
* Upslope snow showers and mountain obscuration will persist much of
Sunday for the Eastern Sierra from TVL to MMH and points south.
Additional light accumulations are possible with MVFR-IFR periods.
-Chris
&&
.Fire Weather...
* Continuing fire weather watches and wind advisories for today with
strong gusty SW winds and low RH across lower elevations. Peak
winds between roughly Noon to 6 PM ahead of an incoming cold
front. Noon to 9 PM for the Eastern Sierra. Main concern is rapid
fire spread in parched grasses from dry winter thus far. Also
since it's a weekend day there will be more people out on public
lands. Strong N/NE winds continue in lower elevations of the E
Sierra Sunday and early Monday but RH should be higher with
much colder temps.
* Good bet for snow across the region this evening into Sunday
morning. This should at least temporarily relieve the dryness in
fine fuels, but also provide for some fresh snow to help with
prescribed burning next week. Could be some air stagnation issues
in valleys with light winds Tuesday-Wednesday, but mixing is
improving with longer days. Tuesday is probably the day with
lowest ventilation.
-Chris
&&
.REV Watches/Warnings/Advisories...
NV...Wind Advisory from 1 PM this afternoon to 1 AM PST Sunday NVZ001.
Lake Wind Advisory from 7 AM this morning to 10 PM PST this
evening for Lake Tahoe in NVZ002.
Winter Weather Advisory from 6 PM this evening to noon PST
Sunday NVZ002.
Winter Weather Advisory from midnight tonight to 1 PM PST Sunday
NVZ001.
Fire Weather Watch from 11 AM PST this morning through this
afternoon NVZ459.
Fire Weather Watch from 11 AM PST this morning through this
afternoon NVZ450.
Winter Weather Advisory from 8 PM this evening to 10 AM PST
Sunday NVZ003.
Wind Advisory from 10 AM this morning to 10 PM PST this evening
NVZ003.
Blowing Dust Advisory from 10 AM this morning to 10 PM PST this
evening NVZ004.
Lake Wind Advisory from 1 PM this afternoon to 7 PM PST this
evening for Pyramid Lake in NVZ004.
Fire Weather Watch from 11 AM PST this morning through this
afternoon NVZ453.
CA...Winter Weather Advisory from 5 PM this afternoon to 4 AM PST
Sunday CAZ071.
Winter Weather Advisory from midnight tonight to 4 PM PST Sunday
CAZ073.
Fire Weather Watch from 11 AM PST this morning through this
afternoon below 6500 feet in CAZ273.
Wind Advisory from 1 PM this afternoon to 1 AM PST Sunday CAZ073.
Lake Wind Advisory from 7 AM this morning to 10 PM PST this
evening for Lake Tahoe in CAZ072.
Winter Weather Advisory from 6 PM this evening to noon PST
Sunday CAZ072.
&&
For more information from the National Weather Service visit...
http://weather.gov/renoThe national radar mosaic for the moment the first event began.
6 high wind. Local standard time, as filed.
Mesonet SIBSV Siberia atop Squaw Summit measured a wind gust of 80 mph (elevation 8700 feet MSL).
Mesonet SUMAM on Ward Peak measured a wind gust of 72 mph (elevation 8483 feet MSL). Several wind gusts ranged from 58 to 71 mph in the 2 hours prior and after the maximum wind gust.
Mesonet MTH03 Mammoth Summit measured an 85 mph wind gust (elevation 11053 feet MSL). Several gusts in the prior and next 2 hours were over 70 mph.
Mesonet MTH02 Mammoth Chair 22 measured an 87 mph wind gust (elevation 10067 feet MSL). Several wind gusts were over 70 mph in the hour prior and after the maximum wind gust of 87 mph.
Mesonet MTH14 Mammoth Chair 1, Tower 9, measured a 63 mph wind gust (elevation 9385 feet MSL).
RAWS UNDC1 in Lundy Canyon (elevation 7032 feet MSL) recorded a 61 mph wind gust.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2020Every state in 2020This day in weather historyWarnings in California, February 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 907918, 907919, 907924, 907923, 907922, 907921.