A long period northwest swell moved through the region in early January bringing high surf to area beaches. Swell heights were observed at around 15 ft with periods of 18 to 19 seconds.
Every event with a place to put it; 4 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 long period northwest swell moved through the region in early January bringing high surf to area beaches. Swell heights were observed at around 15 ft with periods of 18 to 19 seconds. Breaking wave heights were forecast at around 20 to at least 25 feet at favored locations. Strong surf ended up snapping two pilings at the Capitola Wharf prompting the closing of the wharf for repairs. Additionally, multiple water rescues were performed up and down the coast.
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 Jan 1, 9:45 AM PST, 15 minutes earlier.
Area Forecast Discussion
National Weather Service San Francisco Bay Area
945 AM PST Wed Jan 1 2020
.SYNOPSIS...Dry and mild conditions will persist through Friday
afternoon. A weak system may bring rain to the northern portion of
the Bay Area Friday night and early Saturday, and slightly cooler
temperatures are forecast for the weekend. Large surf will bring
hazardous conditions to area beaches through tonight.
&&
.DISCUSSION...As of 9:30 AM PST Wednesday...High pressure aloft
over the Eastern Pacific will gradually move eastward over
California over the next few days. This will maintain mainly dry
and mild weather across the district through Friday, and perhaps
longer. A weak shortwave trough moving over the ridge could bring
a few sprinkles to far northern Sonoma county this afternoon,
however, most areas will be dry. High temperatures over the next
few days will range from the upper 50s to lower 60s, and overnight
lows will mainly be in the 40s.
The next weather system to affect the area will arrive late
Friday. The system is forecast to focus farther north, however,
with rain chances mainly in the North Bay. The 12Z NAM continues
to be most bullish with this system and brings light rain as far
south as northern Monterey County. A few ensemble members from
both the 06Z GFS and 06Z ECMWF also indicate light rainfall to
the Monterey Airport during this time, but overall the solutions
are dry.
Dry conditions are then expected from the latter half of the
weekend into next week. Longer range models bring another trough
to the west coast by the middle of next week, with additional
systems after that. There are differences in timing, though, as
well as how far south precipitation will develop.
&&
.AVIATION...as of 9:45 AM PST Wednesday...For 18z tafs. A frontal
system moving into northern California today will bring in low
level moisture to the area. Latest models show in increase in low
level moisture this afternoon into this evening. Satellite and obs
show low clouds remain around the Bay Area at between 700 and
1,100 ft AGL. Expecting this to last for another couple of hours.
MVFR cigs are forecast to develop by this afternoon and continue
into the early evening. This remains a low confidence forecast.
Conditions will be monitored throughout the day and tafs will be
updated as needed. Models show low levels drying out again
tomorrow morning for most spots. Onshore winds this afternoon
around 10-15 kt with locally higher gusts around KSFO of about 20
kt.
Vicinity of KSFO...IFR cigs remain around the southern San
Francisco Bay this morning. Bases are still expected to rise over
the next few hours, but confidence is low. Clouds around 3,000 ft
then forecast to persist into the late afternoon. There may be
periods of BKN MVFR cigs again overnight before models show
conditions drying out at low levels again tomorrow morning. W to
NW winds to persist through the period around 10-15 kt with
higher gusts this afternoon to around 20 kt.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...Satellite shows MVFR cigs just offshore
of the Peninsula and are expected to spread inland by this
afternoon and then continue the rest of the day and tonight. S to
SE winds this morning to turn onshore this afternoon 10-15 kt.
&&
.MARINE...as of 8:07 AM PST Wednesday...Moderate northwest winds
will persist over the waters today as high pressure remains over
the eastern Pacific and a thermal trough resides along the
California coast. Northwest winds will briefly increase tonight
and tomorrow before diminishing and turning southerly by Friday as
a low pressure system moves into the waters off the Pacific
Northwest. Once the system moves inland, winds will return out of
the northwest on Saturday and increase through the weekend. A
large long period northwest swell has arrived and will continue to
build into tonight. This swell could produce some very high
breakers. Swells will subside in height and period into Friday.
The combination of winds and seas will generate hazardous seas
conditions over the waters.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...High Surf Advisory...CAZ006-505-509-529-530
SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...Pt Reyes to Pigeon Pt 0-10 nm
SCA...Pigeon Pt to Pt Pinos 0-10 nm
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
&&
PUBLIC FORECAST: Sims
AVIATION: AS
MARINE: AS
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www.youtube.com/nwsbayareaThe national radar mosaic for the moment the first event began.
3 high surf, 1 rip current. Local standard time, as filed.
Strong surf snapped two pilings at the Capitola Wharf prompting the closure of the wharf for repairs https://www.ksbw.com/article/the-panhandler-murder-hoax-baltimore-jacquelyn-smith/30784916.
A woman was at Cowell Ranch State Beach on January 2nd with her family and dog when her dog was caught in the waves. The woman went after her dog and was then swept out to see. The dog was able to get back to shore on her own and the woman was rescued and brought back to shore https://www.hmbreview.com/news/woman-dog-safe-after-being-swept-to-sea/article_3956e254-2dac-11ea-94b1-df6a9d23a902.html.
Crews rescued kayakers in Pacifica due to rough surf conditions https://www.nbcbayarea.com/news/local/high-surf-advisory-in-effect-along-bay-area-coastline/2208924/. Timing is estimated.
A surfer was rescued at Mavericks in rough conditions https://www.nbcbayarea.com/news/local/high-surf-advisory-in-effect-along-bay-area-coastline/2208924/. Timing is estimated.
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, January 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: 867585, 867586, 867588, 867589.