Alert archive / Hawaii / High Surf Warnings in 2021

High Surf Warning 6, NWS Honolulu, HI

November 1, 2021Honolulu County, Kauai County, Kalawao County, Hawaii

NWS Honolulu, HI issued this high surf warning at Nov 1, 2021, 3:33 PM HST for Honolulu County, Kauai County, Kalawao County, Hawaii. It took effect at Nov 2, 2021, 3:23 AM HST. It was in force for 24 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Nov 1, 2021, 3:33 PM HST (01:33 UTC)
In effect from
Nov 2, 2021, 3:23 AM HST
Expired
Nov 3, 2021, 3:17 AM HST
In force
24 hr
Issued by
NWS Honolulu, HI

Counties Honolulu County, HI, Kalawao County, HI, Kauai County, HI

The radar

The Molokai radar (PHMO), 116 km from the middle of the area, began a volume at 01:34 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

Lihue, (PHLI), launched 00:00Z, 1.6 hours before the alert went out and 127 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, Lihue, at 00:00Z on 2021-11-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lihue, at 00:00Z on 2021-11-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 square meters per square second.1939Sfc1 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
6 J/kg
Mixed-layer CIN
-251 J/kg
Mixed-layer LCL
880 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
54 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

586 
WHHW40 PHFO 020133
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
333 PM HST Mon Nov 1 2021

...HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF NIIHAU
KAUAI OAHU MOLOKAI AND FOR NORTH FACING SHORES OF MAUI...

.A gradual downward trend of the current north-northwest swell is
anticipated this evening through the first part of tonight. However,
a larger and more significant swell will build quickly late tonight
into Tuesday. This larger swell is expected to drive surf heights
to warning levels along exposed north and west facing shores late
tonight for Kauai and Tuesday for Oahu, Molokai, and Maui.

HIZ001-003-006-007-017-029-037-039-040-045-047-021445-
/O.CAN.PHFO.SU.Y.0028.000000T0000Z-211102T0400Z/
/O.NEW.PHFO.SU.W.0006.211102T1600Z-211103T1600Z/
Niihau-Kauai Southwest-Waianae Coast-Oahu North Shore-
Maui Windward West-Kauai North-Molokai Windward-Molokai North-
Molokai West-Maui Central Valley North-Windward Haleakala-
333 PM HST Mon Nov 1 2021

...HIGH SURF WARNING IN EFFECT FROM 6 AM TUESDAY TO 6 AM HST
WEDNESDAY...
...HIGH SURF ADVISORY IS CANCELLED...

* WHAT...For north facing shores, surf 8 to 12 feet tonight,
  increasing to 22 to 26 feet late tonight into Tuesday. For west
  facing shores, surf 7 to 10 feet tonight, increasing to 15 to 
  20 feet late tonight into Tuesday.

* WHERE...North and west facing shores of Niihau, Kauai, Oahu and
  Molokai, and north facing shores of Maui.

* WHEN...From 6 AM Tuesday to 6 AM HST Wednesday.

* IMPACTS...High. Expect ocean water occasionally sweeping across
  portions of beaches, very strong breaking waves, and strong
  longshore and rip currents. Breaking waves may occasionally
  impact harbors making navigating the harbor channel dangerous.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large, breaking surf, significant shorebreak, and dangerous currents
make entering the water very hazardous. Beachgoers, swimmers, and
surfers should heed all advice given by ocean safety officials 
and exercise caution.

&&

$$
4 follow-up statements
143 
WHHW40 PHFO 021323
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
323 AM HST Tue Nov 2 2021

...HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF NIIHAU
KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES OF MAUI...

.A large north-northwest swell will bring warning level surf to 
the exposed north and west facing shores of most islands today, 
beginning with Kauai at around sunrise, and the remaining islands
from Oahu to Maui the rest of today. Warning level surf will 
continue through tonight, although the swell will be subsiding. 
Once the surf lowers to below warning levels, expect a High Surf 
Advisory to be issued.

HIZ001-003-006-007-017-029-037-039-040-045-047-030230-
/O.EXT.PHFO.SU.W.0006.211102T1323Z-211103T1600Z/
Niihau-Kauai Southwest-Waianae Coast-Oahu North Shore-
Maui Windward West-Kauai North-Molokai Windward-Molokai North-
Molokai West-Maui Central Valley North-Windward Haleakala-
323 AM HST Tue Nov 2 2021

...HIGH SURF WARNING NOW IN EFFECT UNTIL 6 AM HST WEDNESDAY...

* WHAT...For north facing shores, surf 22 to 26 feet today,
  continuing through tonight. For west facing shores, surf 15 to
  20 feet through tonight. 

* WHERE...North and west facing shores of Niihau, Kauai, Oahu 
  and Molokai, and north facing shores of Maui.

* WHEN...Until 6 AM HST Wednesday.

* IMPACTS...High. Expect ocean water occasionally sweeping 
  across portions of beaches, very strong breaking waves, and 
  strong longshore and rip currents. Breaking waves may 
  occasionally impact harbors making navigating the harbor 
  channel dangerous.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large, breaking surf, significant shorebreak, and dangerous currents
make entering the water very hazardous. Anyone entering the water
could face significant injury or death.

&&

$$
963 
WHHW40 PHFO 022127
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
1127 AM HST Tue Nov 2 2021

...HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF NIIHAU
KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES OF MAUI...

.A large north-northwest swell will peak this afternoon through this
evening and then steadily decline Wednesday.


HIZ001-003-006-007-017-029-037-039-040-045-047-031030-
/O.CON.PHFO.SU.W.0006.000000T0000Z-211103T1600Z/
Niihau-Kauai Southwest-Waianae Coast-Oahu North Shore-
Maui Windward West-Kauai North-Molokai Windward-Molokai North-
Molokai West-Maui Central Valley North-Windward Haleakala-
1127 AM HST Tue Nov 2 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 AM HST WEDNESDAY...

* WHAT...For north facing shores, surf 20 to 30 feet today,
  gradually lowering tonight. For west facing shores, surf 18 to
  22 feet today, gradually lowering tonight.

* WHERE...North and west facing shores of Niihau, Kauai, Oahu 
  and Molokai, and north facing shores of Maui.

* WHEN...Until 6 AM HST Wednesday.

* IMPACTS...High. Expect ocean water occasionally sweeping 
  across portions of beaches, very strong breaking waves, and 
  strong longshore and rip currents. Breaking waves may 
  occasionally impact harbors making navigating the harbor 
  channel dangerous.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large, breaking surf, significant shorebreak, and dangerous
currents make entering the water very hazardous. Anyone entering
the water could face significant injury or death.

&&

$$
867 
WHHW40 PHFO 030159
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
359 PM HST Tue Nov 2 2021

...HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF NIIHAU
KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES OF MAUI...

.A large north-northwest swell will steadily decline Wednesday.
Surf may hold near warning levels through Wednesday.

HIZ001-003-006-007-017-029-037-039-040-045-047-031500-
/O.CON.PHFO.SU.W.0006.000000T0000Z-211103T1600Z/
Niihau-Kauai Southwest-Waianae Coast-Oahu North Shore-
Maui Windward West-Kauai North-Molokai Windward-Molokai North-
Molokai West-Maui Central Valley North-Windward Haleakala-
359 PM HST Tue Nov 2 2021

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 AM HST WEDNESDAY...

* WHAT...For north facing shores, surf 20 to 30 feet, lowering
  tonight to 18 to 24 feet Wednesday. For west facing shores, surf
  18 to 22 feet, lowering to 12 to 16 ft Wednesday.

* WHERE...North and west facing shores of Niihau, Kauai, Oahu 
  and Molokai, and north facing shores of Maui.

* WHEN...Until 6 AM HST Wednesday.

* IMPACTS...High. Expect ocean water occasionally sweeping 
  across portions of beaches, very strong breaking waves, and 
  strong longshore and rip currents. Breaking waves may 
  occasionally impact harbors making navigating the harbor 
  channel dangerous.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Large, breaking surf, significant shorebreak, and dangerous
currents make entering the water very hazardous. Anyone entering
the water could face significant injury or death.

&&

$$
849 
WHHW40 PHFO 031317
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
317 AM HST Wed Nov 3 2021

...HIGH SURF ADVISORY FOR NORTH AND WEST FACING SHORES OF NIIHAU 
KAUAI OAHU AND MOLOKAI AND NORTH FACING SHORES OF MAUI...

.Surf has subsided to below warning levels, and will continue to
lower through tonight. 

HIZ001-003-006-007-017-029-037-039-040-045-047-040230-
/O.CAN.PHFO.SU.W.0006.000000T0000Z-211103T1600Z/
/O.NEW.PHFO.SU.Y.0029.211103T1317Z-211104T1600Z/
Niihau-Kauai Southwest-Waianae Coast-Oahu North Shore-
Maui Windward West-Kauai North-Molokai Windward-Molokai North-
Molokai West-Maui Central Valley North-Windward Haleakala-
317 AM HST Wed Nov 3 2021

...HIGH SURF ADVISORY IN EFFECT UNTIL 6 AM HST THURSDAY...
...HIGH SURF WARNING IS CANCELLED...

* WHAT...For north facing shores, surf 18 to 24 feet, lowering to
  8 to 12 Thursday. For west facing shores, surf 14 to 18 feet,
  lowering to 4 to 6 feet Thursday.

* WHERE...North and west facing shores of Niihau, Kauai, Oahu 
  and Molokai, and north facing shores of Maui.

* WHEN...Until 6 AM HST Thursday.

* IMPACTS...Moderate. Expect strong breaking waves, shore break, 
  and strong longshore and rip currents making swimming 
  difficult and dangerous.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Beachgoers, swimmers, and surfers should heed all advice given by
ocean safety officials and exercise caution.

&&

$$

The office that day

Everything else NWS Honolulu, HI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 1, 3:27 PM HSTSmall Craft AdvisoryHFO6 days

Nearby

High Surf Warnings in Hawaii, 2021Every high surf warning 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.