Alert archive / Hawaii / High Surf Advisories in 2021

High Surf Advisory 2, NWS Honolulu, HI

January 4, 2021Honolulu County, Kauai County, Kalawao County, Hawaii

NWS Honolulu, HI issued this high surf advisory at Jan 4, 2021, 4:37 AM HST for Honolulu County, Kauai County, Kalawao County, Hawaii. It was in force for 4 days.

The area

The counties it named.

The facts

Issued
Jan 4, 2021, 4:37 AM HST (14:37 UTC)
Expired
Jan 8, 2021, 3:22 PM HST
In force
4 days
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 14:40 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 12:00Z, 2.6 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 12:00Z on 2021-01-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 82 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 12:00Z on 2021-01-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 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
82 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
795 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
-16 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

783 
WHHW40 PHFO 041437 CCA
CFWHFO

Coastal Hazard Message...CORRECTED
National Weather Service Honolulu HI
437 AM HST Mon Jan 4 2021

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

.A northwest swell will produce advisory level surf across exposed
shores of most of the smaller islands through Tuesday afternoon.
This advisory may need to be extended later this week as
additional northwest swells arrive.

HIZ001>003-006>008-012-013-017-019-020-050245-
/O.NEW.PHFO.SU.Y.0002.210104T1437Z-210106T0400Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
437 AM HST Mon Jan 4 2021

...HIGH SURF ADVISORY IN EFFECT UNTIL 6 PM HST TUESDAY...

* WHAT...Surf of 14 to 18 feet along the north facing shores of
  Niihau, Kauai, Oahu, Molokai, and Maui; and 10 to 14 feet along
  the west facing shores of Niihau, Kauai, Oahu, and Molokai.

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

* WHEN...Until 6 PM HST Tuesday.

* 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.

Boaters should expect recreational surfers and body boarders
utilizing harbor channels to access surfing areas.

&&

$$
10 follow-up statements
170 
WHHW40 PHFO 050209
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
409 PM HST Mon Jan 4 2021

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

.A large northwest swell is producing advisory level surf across 
the most northern and western exposed shores of the smaller islands
through Wednesday morning. This advisory may need to be extended 
or upgraded to a surf warning later in the week as additional large
northwest swells pass through the islands.

HIZ001>003-006>008-012-013-017-019-020-051515-
/O.EXT.PHFO.SU.Y.0002.000000T0000Z-210106T1600Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
409 PM HST Mon Jan 4 2021

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

* WHAT...Surf ranging 16 to 24 feet along the north-facing shores
  of Niihau, Kauai, Oahu, Molokai and Maui; and 9 to 16 feet 
  along the west-facing shores of Niihau, Kauai, Oahu and Molokai.

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

* WHEN...Until 6 AM HST Wednesday.

* IMPACTS...Moderate to High. 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.

&&

$$
858 
WHHW40 PHFO 051329
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
329 AM HST Tue Jan 5 2021

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

.Advisory-level surf will continue through the day today along
exposed north and west facing shores of the smaller islands. Surf
may briefly lower below advisory levels tonight as the swell 
eases. 

HIZ001>003-006>008-012-013-017-019-020-060230-
/O.EXT.PHFO.SU.Y.0002.000000T0000Z-210106T0400Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
329 AM HST Tue Jan 5 2021

...HIGH SURF ADVISORY NOW IN EFFECT UNTIL 6 PM HST THIS EVENING...

* WHAT...Surf of 12 to 16 feet this morning lowering to 10 to 15
  feet this afternoon along the north facing shores of Niihau, 
  Kauai, Oahu, Molokai, and Maui; and 8 to 12 feet along the west 
  facing shores of Niihau, Kauai, Oahu, and Molokai.

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

* WHEN...Until 6 PM HST this evening.

* 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.

&&

$$

Gibbs/Bohlin
743 
WHHW40 PHFO 060130
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
330 PM HST Tue Jan 5 2021

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

.Surf will briefly decline below advisory levels this evening,
then rebuild late tonight and Wednesday. North and west shore surf
will peak well above advisory levels Wednesday night and 
Thursday, then decline Thursday night and Friday.

HIZ001>003-006>008-012-013-017-019-020-061430-
/O.EXT.PHFO.SU.Y.0002.000000T0000Z-210108T0400Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
330 PM HST Tue Jan 5 2021

...HIGH SURF ADVISORY NOW IN EFFECT UNTIL 6 PM HST THURSDAY...

* WHAT...After a decline this evening, surf will build on
  Wednesday to 14 to 18 feet along north facing shores of Niihau,
  Kauai, Oahu, Molokai, and Maui; and to 8 to 12 feet along west 
  facing shores of Niihau, Kauai, Oahu, and Molokai.

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

* WHEN...Until 6 PM HST Thursday. Elevated surf may persist into
  Thursday night or early Friday.

* 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.

&&

$$
Wroe
530 
WHHW40 PHFO 061314
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
314 AM HST Wed Jan 6 2021

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

.Surf will gradually build later today and tonight, with surf
along north and west shores peaking well above advisory levels 
into Thursday. Surf will then decline Thursday night and Friday.

HIZ001>003-006>008-012-013-017-019-020-070215-
/O.CON.PHFO.SU.Y.0002.000000T0000Z-210108T0400Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
314 AM HST Wed Jan 6 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 PM HST THURSDAY...

* WHAT...Surf of 10 to 15 feet this morning, increasing to 12 to
  16 feet this afternoon along the north facing shores of Niihau,
  Kauai, Oahu, Molokai, and Maui; and 8 to 12 feet along the west
  facing shores of Niihau, Kauai, Oahu, and Molokai. Surf may grow
  even larger tonight and Thursday. 

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

* WHEN...Until 6 PM HST Thursday, but high surf may continue
  through  the weekend.

* 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. Know your limits; 
when in doubt, do not go out.

&&

$$

Birchard
343 
WHHW40 PHFO 070125
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
325 PM HST Wed Jan 6 2021

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

.Surf will gradually build into tonight, with surf along north 
and west shores peaking well above advisory levels into Thursday. 
Surf will then decline Thursday night and Friday.

HIZ001>003-006>008-012-013-017-019-020-071430-
/O.CON.PHFO.SU.Y.0002.000000T0000Z-210108T0400Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
325 PM HST Wed Jan 6 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 PM HST THURSDAY...

* WHAT...Surf of 12 to 16 feet this afternoon, increasing to 18 to
  22 feet tonight and Thursday along the north facing shores of
  Niihau, Kauai, Oahu, Molokai, and Maui. Surf of 8 to 12 feet
  this afternoon, increasing to 12 to 16 feet tonight and Thursday
  along the west facing shores of Niihau, Kauai, Oahu, and
  Molokai.

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

* WHEN...Until 6 PM HST Thursday. High surf may persist through
  Thursday night, with another large swell possible this the
  weekend.

* 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. Know your limits;
when in doubt, do not go out.

&&

$$
Wroe
365 
WHHW40 PHFO 070416 CCA
CFWHFO

Coastal Hazard Message...CORRECTED
National Weather Service Honolulu HI
616 PM HST Wed Jan 6 2021

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

.Surf will gradually build tonight with surf along north and west
shores peaking well above advisory levels into Thursday. Surf 
will then decline Thursday night and Friday.

HIZ001>003-006>008-012-013-017-019-020-071430-
/O.COR.PHFO.SU.Y.0002.000000T0000Z-210108T0400Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
616 PM HST Wed Jan 6 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 PM HST THURSDAY...

* WHAT...Surf will increase to 18 to 22 feet tonight and Thursday
  along the north-facing shores of Niihau, Kauai, Oahu, Molokai
  and Maui. Surf will lift to 12 to 16 feet tonight and Thursday
  along the west-facing shores of Niihau, Kauai, Oahu and  
  Molokai.

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

* WHEN...Until 6 PM HST Thursday. High surf may persist through
  Thursday night with another north swell possible this weekend.

* 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. Know your limits;
when in doubt, do not go out.

&&

$$
633 
WHHW40 PHFO 071415
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
415 AM HST Thu Jan 7 2021

...HIGH SURF ADVISORY THROUGH FRIDAY MORNING...

.A large northwest swell will be passing through the local Hawaiian
waters today. This will peak XL surf to well above advisory levels
along the northern and western exposed shorelines of Niihau, Kauai,
Oahu, Molokai and the northern facing shores of Maui. Surf will 
be lowering on Friday.

HIZ001>003-006>008-012-013-017-019-020-080315-
/O.EXT.PHFO.SU.Y.0002.000000T0000Z-210108T1600Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
415 AM HST Thu Jan 7 2021

...HIGH SURF ADVISORY NOW IN EFFECT UNTIL 6 AM HST FRIDAY...

* WHAT...Surf will increase to 18 to 24 feet today along the
  north-facing shores of Niihau, Kauai, Oahu, Molokai and Maui.
  Surf will lift to 12 to 16 feet today along the west-facing 
  shores of Niihau, Kauai, Oahu and Molokai.

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

* WHEN...Until 6 AM HST Friday.

* 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.

Boaters should expect recreational surfers and body boarders
utilizing harbor channels to access surfing areas.

&&

$$
630 
WHHW40 PHFO 080130
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
330 PM HST Thu Jan 7 2021

...HIGH SURF ADVISORY THROUGH FRIDAY AFTERNOON...

.A large northwest swell will continue to produce advisory level
surf along most north and west facing shores.

HIZ001>003-006>008-012-013-017-019-020-081430-
/O.EXT.PHFO.SU.Y.0002.000000T0000Z-210109T0400Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
330 PM HST Thu Jan 7 2021

...HIGH SURF ADVISORY NOW IN EFFECT UNTIL 6 PM HST FRIDAY...

* WHAT...Surf heights of 18 to 24 feet tonight and 14 to 18 feet
  on Friday along north facing shores. Surf heights of 12 to 16
  feet tonight and 9 to 12 feet Friday along west facing shores. 

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

* WHEN...Until 6 PM HST Friday.

* 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.

&&

$$

Burke
118 
WHHW40 PHFO 081334
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
334 AM HST Fri Jan 8 2021

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

.A large northwest swell will continue to produce advisory level
surf along most north and west facing shores.

HIZ001>003-006>008-012-013-017-019-020-090245-
/O.CON.PHFO.SU.Y.0002.000000T0000Z-210109T0400Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
334 AM HST Fri Jan 8 2021

...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 PM HST THIS
EVENING...

* WHAT...Surf heights of 14 to 18 feet this morning, lowering to
  12 to 16 ft by this afternoon along north-facing shores. Surf
  heights of 8 to 12 feet today along west-facing shores.

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

* WHEN...Until 6 PM HST this evening.

* 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.

Boaters should expect recreational surfers and body boarders
utilizing harbor channels to access surfing areas.

&&

$$

RCB/PB
719 
WHHW40 PHFO 090122
CFWHFO

Coastal Hazard Message
National Weather Service Honolulu HI
322 PM HST Fri Jan 8 2021

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

HIZ001>003-006>008-012-013-017-019-020-090230-
/O.CAN.PHFO.SU.Y.0002.000000T0000Z-210109T0400Z/
Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-
Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward-
Maui Windward West-Maui Central Valley-Windward Haleakala-
322 PM HST Fri Jan 8 2021

...HIGH SURF ADVISORY IS CANCELLED...

The current north-northwest swell has dropped below advisory
thresholds. A new north swell is expected late Saturday and will
likely bring another round of advisory level surf by Saturday
night.

$$

Nearby

High Surf Advisories in Hawaii, 2021Every high surf 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.