Alert archive / California / Coastal Flood Advisories in 2021

Coastal Flood Advisory 3, NWS Eureka, CA

January 11, 2021Del Norte County, Humboldt County, California

NWS Eureka, CA issued this coastal flood advisory at Jan 11, 2021, 2:17 PM PST for Del Norte County, Humboldt County, California. It took effect at Jan 12, 2021, 9:00 AM PST. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Jan 11, 2021, 2:17 PM PST (22:17 UTC)
In effect from
Jan 12, 2021, 9:00 AM PST
Expired
Jan 12, 2021, 12:00 PM PST
In force
3 hr
Issued by
NWS Eureka, CA

Counties Del Norte County, CA, Humboldt County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 86 km from the middle of the area, began a volume at 22:17 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Medford/Jackson, OR (KMFR), launched 12:00Z, 10.3 hours before the alert went out and 158 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Medford/Jackson, OR at 12:00Z on 2021-01-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Medford/Jackson, OR at 12:00Z on 2021-01-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
685 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
200 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

521 
WHUS46 KEKA 112217
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
217 PM PST Mon Jan 11 2021

...High tides and large surf Tuesday...

Strong winds, large surf and high tides will bring another round 
of coastal flooding Tuesday. Large waves may wash over vulnerable 
coastal roads again.

CAZ101-120630-
/O.NEW.KEKA.SU.Y.0005.210112T1500Z-210113T1600Z/
/O.NEW.KEKA.CF.Y.0003.210112T1700Z-210112T2000Z/
Coastal Del Norte-
217 PM PST Mon Jan 11 2021

...HIGH SURF ADVISORY IN EFFECT FROM 7 AM TUESDAY TO 8 AM PST
WEDNESDAY...
...COASTAL FLOOD ADVISORY IN EFFECT FROM 9 AM TO NOON PST
TUESDAY...

* WHAT...For the High Surf Advisory, large breaking waves of 22 to
  25. For the Coastal Flood Advisory, High astronomical tides will
  cause minor flooding in low lying areas along the Redwood Coast.
  Up to one/one half foot of saltwater inundation above ground
  level is possible in low lying areas near shorelines and tidal 
  waterways (Between 8.8 and 8.9 feet MLLW at the Crescent City 
  tide gauge).

* WHERE...Coastal Del Norte County.

* WHEN...For the High Surf Advisory, from 7 AM Tuesday to 8 AM PST
  Wednesday. For the Coastal Flood Advisory, from 9 AM to noon PST
  Tuesday.

* IMPACTS...Flooding of lots, parks, and roads with only isolated
  road closures expected. Dangerous surfing conditions and
  localized beach erosion. Beachcombing is highly discouraged!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ103-120630-
/O.NEW.KEKA.SU.Y.0005.210112T1500Z-210113T1600Z/
/O.NEW.KEKA.CF.Y.0003.210112T1700Z-210112T2000Z/
Northern Humboldt Coast-
217 PM PST Mon Jan 11 2021

...HIGH SURF ADVISORY IN EFFECT FROM 7 AM TUESDAY TO 8 AM PST
WEDNESDAY...
...COASTAL FLOOD ADVISORY IN EFFECT FROM 9 AM TO NOON PST
TUESDAY...

* WHAT...For the High Surf Advisory, large breaking waves 22 to 25
  feet. For the Coastal Flood Advisory, High astronomical tides
  will cause minor flooding in low lying areas along the Redwood
  Coast. Up to one half foot of saltwater inundation above ground
  level is possible in low lying areas near shorelines and tidal
  waterways (Between 8.9 and 9.1 feet MLLW at the north spit tide
  gauge).

* WHERE...Northern Humboldt Coast County.

* WHEN...For the High Surf Advisory, from 7 AM Tuesday to 8 AM PST
  Wednesday. For the Coastal Flood Advisory, from 9 AM to noon PST
  Tuesday.

* IMPACTS...Flooding of lots, parks, and roads with only isolated
  road closures expected. Dangerous surfing conditions and
  localized beach erosion. Beachcombing is highly discouraged!

* ADDITIONAL DETAILS...King Salmon and Jackson Ranch Rd in the
  Arcata Bottoms may see minor flooding due elevated water levels.
  New Navy Base Road and Centerville Beach road may see waves
  break over them again.
  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ104-120630-
/O.NEW.KEKA.SU.Y.0005.210112T1500Z-210113T1600Z/
Southwestern Humboldt-
217 PM PST Mon Jan 11 2021

...HIGH SURF ADVISORY IN EFFECT FROM 7 AM TUESDAY TO 8 AM PST
WEDNESDAY...

* WHAT...Large breaking waves 22 to 25 feet.

* WHERE...Southwestern Humboldt County.

* WHEN...From 7 AM Tuesday to 8 AM PST Wednesday.. .

* IMPACTS...Dangerous surfing conditions and localized beach
  erosion. Beachcombing is highly discouraged!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ109-120630-
/O.NEW.KEKA.SU.Y.0005.210112T1800Z-210113T1400Z/
Mendocino Coast-
217 PM PST Mon Jan 11 2021

...HIGH SURF ADVISORY IN EFFECT FROM 10 AM TUESDAY TO 6 AM PST
WEDNESDAY...

* WHAT...Large breaking waves 22 to 25.

* WHERE...Mendocino Coast County.

* WHEN...From 10 AM Tuesday to 6 AM PST Wednesday.. .

* IMPACTS...Dangerous surfing conditions and localized beach
  erosion. Beachcombing is highly discouraged!

* ADDITIONAL DETAILS...These breakers may run up into parking 
  lots or on low-lying roads briefly during high tide.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$
3 follow-up statements
723 
WHUS46 KEKA 120501
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
901 PM PST Mon Jan 11 2021

...High tides and large surf Tuesday...

Strong winds, large surf and high tides will bring another round
of coastal flooding Tuesday. Large waves may wash over vulnerable
coastal roads again.

CAZ101-121315-
/O.CON.KEKA.SU.Y.0005.210112T1500Z-210113T1600Z/
/O.CON.KEKA.CF.Y.0003.210112T1700Z-210112T2000Z/
Coastal Del Norte-
901 PM PST Mon Jan 11 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 7 AM TUESDAY TO 8 AM
PST WEDNESDAY...
...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM TO NOON PST
TUESDAY...

* WHAT...For the High Surf Advisory, large breaking waves of 22 
  to 25. For the Coastal Flood Advisory, High astronomical tides 
  will cause minor flooding in low lying areas along the Redwood 
  Coast. Up to one/one half foot of saltwater inundation above 
  ground level is possible in low lying areas near shorelines 
  and tidal waterways (Between 8.8 and 8.9 feet MLLW at the 
  Crescent City tide gauge).

* WHERE...Coastal Del Norte County.

* WHEN...For the High Surf Advisory, from 7 AM Tuesday to 8 AM 
  PST Wednesday. For the Coastal Flood Advisory, from 9 AM to 
  noon PST Tuesday.

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Dangerous surfing conditions 
  and localized beach erosion. Beachcombing is highly 
  discouraged!.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ103-121315-
/O.CON.KEKA.SU.Y.0005.210112T1500Z-210113T1600Z/
/O.CON.KEKA.CF.Y.0003.210112T1700Z-210112T2000Z/
Northern Humboldt Coast-
901 PM PST Mon Jan 11 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 7 AM TUESDAY TO 8 AM
PST WEDNESDAY...
...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM TO NOON PST
TUESDAY...

* WHAT...For the High Surf Advisory, large breaking waves 22 to 
  25 feet. For the Coastal Flood Advisory, High astronomical 
  tides will cause minor flooding in low lying areas along the 
  Redwood Coast. Up to one half foot of saltwater inundation 
  above ground level is possible in low lying areas near 
  shorelines and tidal waterways (Between 8.9 and 9.1 feet MLLW 
  at the north spit tide gauge).

* WHERE...Northern Humboldt Coast County.

* WHEN...For the High Surf Advisory, from 7 AM Tuesday to 8 AM 
  PST Wednesday. For the Coastal Flood Advisory, from 9 AM to 
  noon PST Tuesday.

* IMPACTS...Flooding of lots, parks, and roads with only isolated
  road closures expected. Dangerous surfing conditions and
  localized beach erosion. Beachcombing is highly discouraged!.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ104-121315-
/O.CON.KEKA.SU.Y.0005.210112T1500Z-210113T1600Z/
Southwestern Humboldt-
901 PM PST Mon Jan 11 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 7 AM TUESDAY TO 8 AM
PST WEDNESDAY...

* WHAT...Large breaking waves 22 to 25 feet.

* WHERE...Southwestern Humboldt County.

* WHEN...From 7 AM Tuesday to 8 AM PST Wednesday.. .

* IMPACTS...Dangerous surfing conditions and localized beach 
  erosion. Beachcombing is highly discouraged!.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ109-121315-
/O.CON.KEKA.SU.Y.0005.210112T1800Z-210113T1400Z/
Mendocino Coast-
901 PM PST Mon Jan 11 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 10 AM TUESDAY TO
6 AM PST WEDNESDAY...

* WHAT...Large breaking waves 22 to 25.

* WHERE...Mendocino Coast County.

* WHEN...From 10 AM Tuesday to 6 AM PST Wednesday.. .

* IMPACTS...Dangerous surfing conditions and localized beach
  erosion. Beachcombing is highly discouraged!.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$
313 
WHUS46 KEKA 121227
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
427 AM PST Tue Jan 12 2021

...High tides and large surf today...

Strong winds, large surf and high tides will bring another round
of coastal flooding today. Large waves may wash over vulnerable 
coastal roads again.

CAZ101-122015-
/O.CON.KEKA.SU.Y.0005.210112T1500Z-210113T1600Z/
/O.CON.KEKA.CF.Y.0003.210112T1700Z-210112T2000Z/
Coastal Del Norte-
427 AM PST Tue Jan 12 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 8 AM PST
WEDNESDAY...
...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM THIS
MORNING TO NOON PST TODAY...

* WHAT...For the High Surf Advisory, large breaking waves of 22 
  to 25. For the Coastal Flood Advisory, High astronomical tides 
  will cause minor flooding in low lying areas along the Redwood 
  Coast. Up to one/one half foot of saltwater inundation above 
  ground level is possible in low lying areas near shorelines 
  and tidal waterways (Between 8.8 and 8.9 feet MLLW at the 
  Crescent City tide gauge).

* WHERE...Coastal Del Norte County.

* WHEN...For the High Surf Advisory, until 8 AM PST Wednesday. 
  For the Coastal Flood Advisory, from 9 AM this morning to noon 
  PST today.. .

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Dangerous surfing conditions 
  and localized beach erosion. Beachcombing is highly 
  discouraged!.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ103-122015-
/O.CON.KEKA.SU.Y.0005.210112T1500Z-210113T1600Z/
/O.CON.KEKA.CF.Y.0003.210112T1700Z-210112T2000Z/
Northern Humboldt Coast-
427 AM PST Tue Jan 12 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 8 AM PST
WEDNESDAY...
...COASTAL FLOOD ADVISORY REMAINS IN EFFECT FROM 9 AM THIS
MORNING TO NOON PST TODAY...

* WHAT...For the High Surf Advisory, large breaking waves 22 to 
  25 feet. For the Coastal Flood Advisory, High astronomical 
  tides will cause minor flooding in low lying areas along the 
  Redwood Coast. Up to one half foot of saltwater inundation 
  above ground level is possible in low lying areas near 
  shorelines and tidal waterways (Between 8.9 and 9.1 feet MLLW 
  at the north spit tide gauge).

* WHERE...Northern Humboldt Coast County.

* WHEN...For the High Surf Advisory, until 8 AM PST Wednesday. 
  For the Coastal Flood Advisory, from 9 AM this morning to noon 
  PST today.. .

* IMPACTS...Flooding of lots, parks, and roads with only 
  isolated road closures expected. Dangerous surfing conditions 
  and localized beach erosion. Beachcombing is highly 
  discouraged!.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory indicates that onshore winds and tides
will combine to generate flooding of low areas along the shore.

Feet Above Ground is locally defined as feet above the Highest
Astronomical Tide or HAT.

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ104-122015-
/O.CON.KEKA.SU.Y.0005.210112T1500Z-210113T1600Z/
Southwestern Humboldt-
427 AM PST Tue Jan 12 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 8 AM PST
WEDNESDAY...

* WHAT...Large breaking waves 22 to 25 feet.

* WHERE...Southwestern Humboldt County.

* WHEN...Until 8 AM PST Wednesday.. .

* IMPACTS...Dangerous surfing conditions and localized beach 
  erosion. Beachcombing is highly discouraged!.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$

CAZ109-122015-
/O.CON.KEKA.SU.Y.0005.210112T1800Z-210113T1400Z/
Mendocino Coast-
427 AM PST Tue Jan 12 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT FROM 10 AM THIS MORNING
TO 6 AM PST WEDNESDAY...

* WHAT...Large breaking waves 22 to 25.

* WHERE...Mendocino Coast County.

* WHEN...From 10 AM this morning to 6 AM PST Wednesday.. .

* IMPACTS...Dangerous surfing conditions and localized beach 
  erosion. Beachcombing is highly discouraged!.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

&&

$$
591 
WHUS46 KEKA 122003
CFWEKA

Coastal Hazard Message
National Weather Service Eureka CA
1203 PM PST Tue Jan 12 2021

CAZ101-103-130415-
/O.EXP.KEKA.CF.Y.0003.000000T0000Z-210112T2000Z/
/O.CON.KEKA.SU.Y.0005.000000T0000Z-210113T1600Z/
Coastal Del Norte-Northern Humboldt Coast-
1203 PM PST Tue Jan 12 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 8 AM WEDNESDAY...
...COASTAL FLOOD ADVISORY HAS EXPIRED...

* WHAT...Large breaking waves 22 to 25 feet.

* WHERE...Coastal Del Norte County.

* WHEN...Until 8 AM Wednesday.

* IMPACTS...Dangerous surfing conditions and localized beach
  erosion. Beachcombing is highly discouraged!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

$$

CAZ104-130415-
/O.CON.KEKA.SU.Y.0005.000000T0000Z-210113T1600Z/
Southwestern Humboldt-
1203 PM PST Tue Jan 12 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 8 AM WEDNESDAY...

* WHAT...Large breaking waves 22 to 25 feet.

* WHERE...Southwestern Humboldt County.

* WHEN...Until 8 AM Wednesday.

* IMPACTS...Dangerous surfing conditions and localized beach
  erosion. Beachcombing is highly discouraged!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

$$

CAZ109-130415-
/O.CON.KEKA.SU.Y.0005.000000T0000Z-210113T1400Z/
Mendocino Coast-
1203 PM PST Tue Jan 12 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 AM WEDNESDAY...

* WHAT...Large breaking waves 22 to 25 feet.

* WHERE...Mendocino Coast County.

* WHEN...Until 6 AM Wednesday.

* IMPACTS...Dangerous surfing conditions and localized beach
  erosion. Beachcombing is highly discouraged!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large breaking waves along the coast will lead to increased wave
run-up on beaches with waves topping and washing over large rocks
and jetties. These large waves can be erratic and unpredictable.
Use extra caution near the surf zone as these large waves will be
capable of sweeping people into the frigid and turbulent ocean
water. Mariners traversing the bar are urged to exercise extreme
caution or stay in port until the threat subsides. Please contact
the U.S. Coast Guard for information regarding harbor and bar
closures.

$$

What forecasters said that day

The local office's own words before this coastal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Eureka, CA wrote its last area forecast discussion before this coastal flood advisory went out at Jan 11, 5:22 AM PST, 8 hours 55 minutes earlier.

Area forecast discussion, Jan 11, 5:22 AM PST, 8 hours 55 minutes before
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
522 AM PST Mon Jan 11 2021

.SYNOPSIS...Following a mostly dry and mild day today, widespread
rain and gusty southerly winds will return to the area Monday
night through Tuesday night, with some lingering showers possible
into Wednesday. The heaviest rains will affect Del Norte and
northern Humboldt counties.

&&

.DISCUSSION...Areas of inland valley fog this morning will give
way to some partial sunshine across the interior this afternoon.
Meanwhile at the coast, some dimmed sunshine through high clouds
this morning will lose out to increasing clouds this afternoon as
a significant storm system approaches our area heading into
tonight.

Offshore low pressure well to our northwest will lift NE towards
British Columbia later tonight. This will coincide with a warm
front lifting northeastward toward the Pacific Northwest, bringing
an atmospheric river to bare on Oregon and northern portions of
our CWA. This AR will remain trained on Del Norte and portions of
northern Humboldt with rain and coastal flooding Tuesday
afternoon into Tuesday night before another wave of low pressure
pushes a cold front southward and takes the moisture with it,
allowing showers to diminish on Wednesday. Earlier model solutions
had heavier rain persisting into Wednesday, but thankfully the
trend for now is to tend to dry things out a little quicker.
There is still some uncertainty in the timing and focus of the
heaviest rain through this event, as some of the hi-res models
shift the rain southward a bit quicker on Tuesday, with broader
light to moderate rain expanding into Mendocino and Trinity. At
this time, the heaviest rain is projected to occur during the
daytime hours on Tuesday, particularly around midday. Rain amounts
will be much lower to the south and east across Trinity,
Mendocino and Lake. See the hydrology section below. Snow will be
a non- issue with this event, with snow levels quickly rising from
6000 toward 8000 feet on Tuesday.

In addition to the heavy rain, locally strong winds will be
another concern. The strong low and mid-level jet responsible for
training deep Pacific moisture toward Oregon and far northern
California will reach up to 60 kt at only 1500 feet above sea
level. While the rather stable atmosphere with stratiform rains
will tend to limit that magnitude of wind from reaching the
surface, exposed coastal ridges from Cape Mendocino to Del Norte
will likely see some gusts exceed 50 mph late Monday night through
much of Tuesday. Immediate coastal areas around Crescent City may
also see brief gusts to around 45 mph. Have issued a Wind Advisory
for coastal Del Norte and interior Humboldt and Del Norte above
1500 feet.

After showers taper off on Wednesday, the overall pattern will
favor quieter, milder and drier weather through next weekend as a
ridge of high pressure builds over the West Coast, though a weak
front may give us some brief light rainfall on Friday. EYS/AAD

&&

.AVIATION...LIFR conditions are present this morning for many inland
valleys, with areas of fog and low clouds extending toward the
portions of the coast. However, for the most part, light offshore
flow is allowing the coastal terminals to stay VFR. Increasing high
and mid-level clouds will only help mitigate the fog threat there
through this morning, but would not rule out some patchy shallow fog
through early or mid-morning. Inland valley fog may last until
midday or so. Otherwise, VFR conditions will last into this evening
for much of northwest California, as higher-level cloudiness
increases and southerly winds gradually pick up. Rain will
approach the coast late this evening, moving onshore in Del Norte
county then spreading southward. LLWS is possible for the coast
while the rain moves onshore late tonight as well. This front will
likely linger overhead through Tuesday night, with persistent rain,
lower ceilings and visibilities for much of our area. AAD/TDJ

&&

.MARINE...A period of somewhat calmer seas is forecasted today in
the wake of a large west swell on Sunday. Yet another large, long
period west swell is expected to fill in during the day on Tuesday,
peaking Tuesday night in the high teens, then decaying through the
back half of this week. Another swell may move in early this weekend
as well, and this final one looks a tad smaller than the one on
Tuesday at the moment. Latest model guidance continues to strengthen
the winds associated with an expected front on Tuesday, with
southerly winds likely reaching GALE FORCE in at least the northern
outers late Monday through Tuesday afternoon. Southerly short-period
seas generated from these winds look to peak right around when this
next west swell is peaking, thus a large and chaotic sea state
expected from early Tuesday into early Wednesday morning. After this
frontal passage mid-week, light southerlies persist for a few days
before brisk northerlies potentially develop this weekend. /TDJ

&&

.HYDROLOGY...Rainfall totals from Monday night through Wednesday
are forecast to range from 3 to 4 inches along the Del Norte and
extreme northwest Humboldt County coast to over 6 inches in the
south-facing terrain of Del Norte County. Locally higher rainfall
amounts are possible. The heaviest rains are expected on Tuesday,
particularly around midday, but there may be another passing shot
of heavy rain late Tuesday night or very early Wednesday with a
cold front. Amounts will be much lower around Humboldt Bay;
generally from 1 to 1.5 inches, with similar amounts across
eastern Trinity, less than a half inch in southern Mendocino and
Lake Counties. Have issued a Hydrologic Outlook for this event.

At this time, widespread flooding is not expected. However,
smaller streams may approach bankfull, and standing water is
possible in poor drainage areas. Localized flooding near the coast
may be exacerbated by high astronomical tides and periods of high
surf. Main stem rivers are presently forecast to remain below
flood stage, but quick rises in the river levels are possible,
particularly on the Smith River. Stay tuned! /SEC

&&

.BEACH HAZARDS...The threat for coastal flooding continues on Monday
as we get closer to the highest tides of January. The southerly
winds will be light, but are expected to be big enough to raise
waters levels a quarter to a half of a foot inside Humboldt Bay
bringing them to 8.8 or 8.9 at the North Spit tide gauge. This will
likely bring some flooding to King Salmon and the Arcata Bottoms.
Elsewhere the southerly winds are not expected to be strong enough
to raise the water much above the astronomical tides.

Tuesday the southerly winds increase with GALE FORCE conditions off
the coast. This may bring more widespread coastal flooding to the
area. Astronomical tides will be close the Highest Astronomical
Tides. Waves are not expected to be as large as today, but with
higher tides and stronger winds we could see some similar impacts to
what we saw on Sunday. MKK

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory from 1 AM to 6 PM PST Tuesday for CAZ101-102-
     104>106.

     Coastal Flood Advisory from 8 AM to 11 AM PST this morning for
     CAZ103.

NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory until 3 AM PST
     Wednesday for PZZ450-455.

     Small Craft Advisory until 9 PM PST this evening for PZZ470.

     Gale Warning from 9 PM this evening to 3 PM PST Tuesday for
     PZZ470.

     Coastal Flood Advisory from 8 AM to 11 AM PST this morning for
     PZZ410-415.

     Small Craft Advisory until 9 AM PST Tuesday for PZZ475.

     Hazardous Seas Watch from Tuesday morning through late Tuesday
     night for PZZ475.

&&

Visit us at https://www.weather.gov/eureka

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https://www.facebook.com/NWSEureka
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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png
Hazardous weather outlook, Jan 11, 5:37 AM PST, 8 hours 40 minutes before
Hazardous Weather Outlook
National Weather Service Eureka CA
537 AM PST Mon Jan 11 2021

CAZ101-104-121345-
Coastal Del Norte-Southwestern Humboldt-
537 AM PST Mon Jan 11 2021

...WIND ADVISORY IN EFFECT FROM 1 AM TO 6 PM PST TUESDAY...

This hazardous weather outlook is for northwest California.

.DAY ONE...Today and tonight.

A Wind Advisory is in effect late tonight.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

A Wind Advisory is in effect Tuesday. Additionally, an atmospheric
river will threaten the area Monday night through Tuesday. Periods
of heavy rainfall are likely, especially around Del Norte county. A
large swell and high tides will also bring a localized coastal
flooding threat on Tuesday.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected at this time.

CAZ103-121345-
Northern Humboldt Coast-
537 AM PST Mon Jan 11 2021

...COASTAL FLOOD ADVISORY IN EFFECT UNTIL 11 AM PST THIS MORNING...

This hazardous weather outlook is for northwest California.

.DAY ONE...Today and tonight.

A Coastal Flood Advisory is currently in effect.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Additionally, an atmospheric river will threaten the area Monday
night through Tuesday. Periods of heavy rainfall are likely for
portions of our area. A large swell and high tides will also bring a
localized coastal flooding threat on Tuesday.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected at this time.

CAZ109-121345-
Mendocino Coast-
537 AM PST Mon Jan 11 2021

This hazardous weather outlook is for northwest California.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Another large swell will impact the coast on Tuesday.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected at this time.

CAZ107-108-110>115-121345-
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Northern Lake County-
Southern Lake County-
537 AM PST Mon Jan 11 2021

This hazardous weather outlook is for northwest California.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected at this time.

CAZ102-105-106-121345-
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-
537 AM PST Mon Jan 11 2021

...WIND ADVISORY IN EFFECT FROM 1 AM TO 6 PM PST TUESDAY...

This hazardous weather outlook is for northwest California.

.DAY ONE...Today and tonight.

A Wind Advisory is in effect late tonight.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

A Wind Advisory is in effect Tuesday. Additionally, an atmospheric
river will threaten the area Monday night through Tuesday. Periods
of heavy rainfall are likely, especially around Del Norte county.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected at this time.

The office that day

Everything else NWS Eureka, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 10, 8:53 PM PSTSmall Craft AdvisoryEKA36 hr
Jan 11, 2:03 AM PSTGale WarningEKA49 hr
Jan 11, 2:03 AM PSTHazardous Seas WatchEKA12 hr
Jan 11, 5:42 AM PSTWind AdvisoryEKADel Norte, Humboldt39 hr
Jan 11, 1:24 PM PSTFlood WatchEKADel Norte43 hr
Jan 11, 2:17 PM PSTHigh Surf AdvisoryEKADel Norte, Humboldt, Mendocino40 hr
Jan 11, 2:19 PM PSTHazardous Seas WarningEKA37 hr

Nearby

Coastal Flood Advisories in California, 2021Every coastal flood advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.