A weak atmospheric river impacted the region in early march bringing minor roadway flooding and breezy winds to the region. The main moisture plume made landfall to the south of our region, keeping most of the impacts confined to southern California.
Every event with a place to put it; 2 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 MTR wrote it up.
A weak atmospheric river impacted the region in early march bringing minor roadway flooding and breezy winds to the region. The main moisture plume made landfall to the south of our region, keeping most of the impacts confined to southern California.
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 San Francisco Bay Area, CA wrote its last area forecast discussion before the first event at Mar 5, 4:25 PM PST, 4 hours 7 minutes earlier.
Area Forecast Discussion
National Weather Service San Francisco Bay Area
425 PM PST Tue Mar 5 2019
.SYNOPSIS...After a brief break in precipitation early this
afternoon, more widespread rainfall is forecast to develop over the
region later in the day and continue through Wednesday morning.
Gusty winds and isolated thunderstorms will be possible as the main
frontal system pushes inland overnight. Lingering showers will then
continue through Thursday before diminishing from north to south.
Cooler overnight conditions return late in the week with another
chance of light precipitation this upcoming weekend.
&&
.DISCUSSION...as of 01:36 PM PST Tuesday...As expected, a much
deeper plume of moisture advected inland along the Big Sur Coast
earlier this morning and resulted in an increase in rainfall
rates. During the past 12 hours or so, rainfall amounts range from
about 0.25" to 0.50" in this region. Meanwhile, light
precipitation fell over a good portion of the region with
generally a few hundredths to a few tenths of an inch in the same
timeframe. This weak atmospheric river has since pushed southward
into San Luis Obispo and Santa Barbara Counties with mostly dry
conditions over our region as of early afternoon.
The break in precipitation will likely continue for the next several
hours before a moist onshore flow again increases along the coastal
ranges. Widespread rain is forecast to redevelop first along the
coastal areas and in the North Bay by late this afternoon and then
later in the night across the remainder of the region. This will be
in response to the core of the mid/upper level low that will
approach the coast tonight. Isolated thunderstorms are also forecast
given the increased instability associated with the system. Thus,
moderate to locally heavy rainfall will be possible with the highest
rainfall totals likely along the coastal ranges where an additional
1.00"-2.50" is expected. The mountains along the Big Sur Coast could
see storm total amounts approach 5.00" in the region's wettest
locations. Otherwise, most urban areas can expect 0.25" to 0.50"
with upwards of 1.00"-1.25" in the North Bay Valleys. These rainfall
amounts may result in minor rises in smaller creeks and streams as
well as ponding of water on roadways, especially within any
convection that may develop. With all this, gusty winds will be
possible along the coast, hills, ridges and peaks from tonight into
early Wednesday morning. Gusts up to 45 mph or locally higher cannot
be ruled out, however a widespread damaging wind event is unlikely.
Rain showers are then expected during the day on Wednesday in wake
of the frontal passage. Cannot rule out the possibility of a few
thunderstorms as well, yet confidence is low for a widespread
thunderstorm threat. Showers then look to linger into Wednesday
night and Thursday morning before diminishing from north to south.
Cold air advection will then replace the exiting system and result
in cooler overnight temperatures late in the week. As sky conditions
clear and winds relax, overnight/morning lows will drop into the 30s
for inland valleys and 40s closer to the coast. Meanwhile, daytime
temperatures will continue to warm into the 50s to around 60.
The forecast ensembles continue to indicate the possibility of light
precipitation over the region from Saturday into Sunday as an upper
level trough drops down the West Coast. Confidence is low however as
a more westward track could mean dry conditions region-wide. Will
keep a mention of showers during this timeframe for now and with
snow levels forecast to lower to around 3,500 feet, cannot rule out
some snow in the region's highest peaks.
&&
.AVIATION...as of 4:20 PM PST Tuesday...After an initial band of
rain this morning things have been quiet this afternoon. Upper low
about 400 miles west of the Bay Area will allow rain activity to
pick up this evening. Most of the rain is expected between 06Z and
15Z and will be light to moderate. A few lightning strikes have
been detected near the low center so will have to watch for it as
the low moves in. Cigs will be variable through early evening with
5000 foot cigs occasionally dropping to MVFR range. Cigs will
become predominantly MVFR after 05Z. Southeast winds increasing
through the night switching to south to southwest early Wednesday
morning.
Vicinity of KSFO...Variable clouds will cause ceilings to bounce
between MVFR and VFR this afternoon but will become MVFR after 03Z
with cigs in the 2000-3000 foot range. Southeasterly winds
increasing tonight with gusts to 20-25 kt. Winds will switch to
south to southwest with gusts to 30 kt through Wednesday morning
before decreasing.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...Cigs remain high enough for VFR
conditions to hold through 05Z. Next band of showers will lower
cigs into MVFR after 05Z. Southeast winds will be strongest in the
Salinas Valley with gusts to 35 kt through 05Z and 20-25 kt after
05Z. Gusty winds will impact MRY after 05Z.
&&
.MARINE...as of 03:52 PM PST Tuesday...Gusty southerly winds are
expected across the waters the rest of today, tonight, and
Wednesday morning. Locally stronger gale force winds are expected
in the southern waters, particularly along the coast from Pigeon
Point and southward. These winds will generate steep fresh swell
creating hazardous seas conditions, especially for smaller
vessels. Isolated thunderstorms are possible later today and
overnight which may lead to erratic gusty winds. Mixed light
northwest and a moderate fresh southwest swell across the waters
through the next couple of days.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...GLW...Pigeon Pt to Pt Pinos 0-10 nm
GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm
SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...Pt Arena to Pigeon Pt 10-60 nm
GLW...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 3 AM
SCA...Mry Bay
SCA...Pt Reyes to Pigeon Pt 0-10 nm
SCA...Rough Bar Advisory for SF Bar from 10 PM
SCA...SF Bay
&&
PUBLIC FORECAST: RGass
AVIATION: W Pi
MARINE: DRP
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www.youtube.com/nwsbayareaThe national radar mosaic for the moment the first event began.
5 flood, 3 strong wind, 1 high wind. Local standard time, as filed.
Los Gatos RAWS station reports wind gusts between 45 and 64 mph.
Roadway flooding on Labath Ave near Rohnert Park Expwy.
Las Trampas RAWS measured wind gusts between 45 and 49 mph.
Hawkeye RAWS station reported wind gusts between 45 and 50 mph.
Roadway flooding at I-680 S and Concord Ave off ramp, both lanes flooded.
Flooding on US-101 N and Lucky Dr off ramp.
SB lane flooded at SR-121 and Sears Point Dr.
Roadway flooding at SR-24 E and Saint Stephens Dr off ramp.
Tree fell over on NB Hwy 1 just past Park Ave exit bringing traffic to a halt. One vehicle was involved in an accident, no injuries.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2019Every state in 2019This day in weather historyWarnings in California, March 2019
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: 805523, 805515, 805522, 805521, 805516, 805517, 805518, 805519, 805520.