Alert archive / Hawaii / High Surf Advisories in 2021
High Surf Advisory 5, NWS Honolulu, HI
NWS Honolulu, HI issued this high surf advisory at Jan 14, 2021, 3:44 AM HST for Honolulu County, Kauai County, Kalawao County, Hawaii. It was in force for 48 hr.
The area
The counties it named.
The facts
- Issued
- Jan 14, 2021, 3:44 AM HST (13:44 UTC)
- Expired
- Jan 16, 2021, 3:26 AM HST
- In force
- 48 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 13:44 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, 1.7 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 908 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- -1 m²/s²
- 0-3 km storm-relative helicity
- 43 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
482 WHHW40 PHFO 141344 CFWHFO Coastal Hazard Message National Weather Service Honolulu HI 344 AM HST Thu Jan 14 2021 ...HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND NORTH FACING SHORES OF MAUI... ...HIGH SURF ADVISORY FOR NORTH FACING SHORES OF THE BIG ISLAND... .A very large northwest swell will roll through the coastal waters today and tonight producing very large surf along north and west facing shores of the smaller islands. A more northerly overlapping swell will bring advisory level surf to the north facing shores of the Big Island. HIZ018-141445- /O.CAN.PHFO.SU.W.0002.000000T0000Z-210115T0400Z/ Maui Leeward West- 344 AM HST Thu Jan 14 2021 ...HIGH SURF WARNING IS CANCELLED... Surf along leeward west facing shores of Maui will not reach warning levels. $$ HIZ017-150245- /O.EXB.PHFO.SU.W.0002.000000T0000Z-210115T1600Z/ Maui Windward West- 344 AM HST Thu Jan 14 2021 ...HIGH SURF WARNING IN EFFECT UNTIL 6 AM HST FRIDAY... * WHAT...Dangerously large breaking waves of 25 to 35 feet along north facing shores. * WHERE...North facing shores of Maui. * WHEN...Until 6 AM HST Friday. * IMPACTS...High. Expect ocean water occasionally sweeping across portions of beaches, very strong breaking waves, and strong currents. Breaking waves may occasionally impact harbors making navigating the harbor channels dangerous. Anyone entering the water could face significant injury or death. Coastal flooding is possible. * ADDITIONAL DETAILS...The combination of large surf coinciding with peak monthly high tides may worsen beach erosion along shorelines exposed to north swell during the early morning hours. PRECAUTIONARY/PREPAREDNESS ACTIONS... Large, breaking surf, significant shorebreak, and dangerous currents make entering the water very hazardous. Anyone entering the water could face significant injury or death. && $$ HIZ001>003-006>008-012-013-019-020-150245- /O.EXT.PHFO.SU.W.0002.000000T0000Z-210115T1600Z/ Niihau-Kauai Windward-Kauai Leeward-Waianae Coast- Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward- Maui Central Valley-Windward Haleakala- 344 AM HST Thu Jan 14 2021 ...HIGH SURF WARNING NOW IN EFFECT UNTIL 6 AM HST FRIDAY... * WHAT...Dangerously surf of 25 to 35 feet along north facing shores and 20 to 25 feet along west facing shores. * WHERE...North and west facing shores of Niihau, Kauai, Oahu, Molokai and north facing shores of Maui. * WHEN...Until 6 AM HST Friday. * 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. * ADDITIONAL DETAILS...The combination of large surf coinciding with peak monthly high tides may worsen beach erosion along shorelines exposed to north and west swells during the early morning hours. 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. && $$ HIZ025-150245- /O.NEW.PHFO.SU.Y.0005.210114T1344Z-210115T1600Z/ Big Island North and East- 344 AM HST Thu Jan 14 2021 ...HIGH SURF ADVISORY IN EFFECT UNTIL 6 AM HST FRIDAY... * WHAT...Surf of 12 to 16 feet along north facing shores of the Big Island. * WHERE...North facing shores of the Big Island. * WHEN...Until 6 AM HST Friday. * IMPACTS...Moderate. Expect strong breaking waves, shore break, and strong longshore and rip currents making swimming difficult and dangerous. * ADDITIONAL DETAILS...The combination of large surf coinciding with peak monthly high tides may worsen beach erosion along shorelines exposed to north swell during the early morning hours. PRECAUTIONARY/PREPAREDNESS ACTIONS... Beachgoers, swimmers, and surfers should heed all advice given by ocean safety officials and exercise caution. && $$
7 follow-up statements
348 WHHW40 PHFO 141352 AAA CFWHFO Coastal Hazard Message...UPDATED National Weather Service Honolulu HI 352 AM HST Thu Jan 14 2021 ...HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND NORTH FACING SHORES OF MAUI... ...HIGH SURF ADVISORY FOR NORTH FACING SHORES OF THE BIG ISLAND... .A very large northwest swell will roll through the coastal waters today and tonight producing very large surf along north and west facing shores of the smaller islands. A more northerly overlapping swell will bring advisory level surf to the north facing shores of the Big Island. HIZ001>003-006>008-012-013-017-019-020-150300- /O.CON.PHFO.SU.W.0002.000000T0000Z-210115T1600Z/ Niihau-Kauai Windward-Kauai Leeward-Waianae Coast- Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward- Maui Windward West-Maui Central Valley-Windward Haleakala- 352 AM HST Thu Jan 14 2021 ...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 AM HST FRIDAY... * WHAT...Dangerously large breaking waves of 25 to 35 feet along north facing shores. * WHERE...North facing shores of Maui. * WHEN...Until 6 AM HST Friday. * IMPACTS...High. Expect ocean water occasionally sweeping across portions of beaches, very strong breaking waves, and strong currents. Breaking waves may occasionally impact harbors making navigating the harbor channels dangerous. Anyone entering the water could face significant injury or death. Coastal flooding is possible. * ADDITIONAL DETAILS...The combination of large surf coinciding with peak monthly high tides may worsen beach erosion along shorelines exposed to north swell during the early morning hours. 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. && $$ HIZ025-150300- /O.CON.PHFO.SU.Y.0005.000000T0000Z-210115T1600Z/ Big Island North and East- 352 AM HST Thu Jan 14 2021 ...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 AM HST FRIDAY... * WHAT...Surf of 12 to 16 feet along north facing shores of the Big Island. * WHERE...North facing shores of the Big Island. * WHEN...Until 6 AM HST Friday. * IMPACTS...Moderate. Expect strong breaking waves, shore break, and strong longshore and rip currents making swimming difficult and dangerous. * ADDITIONAL DETAILS...The combination of large surf coinciding with peak monthly high tides may worsen beach erosion along shorelines exposed to north swell during the early morning hours. PRECAUTIONARY/PREPAREDNESS ACTIONS... Beachgoers, swimmers, and surfers should heed all advice given by ocean safety officials and exercise caution. && $$
435 WHHW40 PHFO 150138 CFWHFO Coastal Hazard Message National Weather Service Honolulu HI 338 PM HST Thu Jan 14 2021 ...HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND NORTH FACING SHORES OF MAUI... ...HIGH SURF ADVISORY FOR NORTH FACING SHORES OF THE BIG ISLAND... .A very large northwest swell will hold through tonight, producing very large surf along north and west facing shores of the smaller islands, then quickly lower Friday. A more northerly overlapping swell will bring advisory level surf to the north facing shores of the Big Island. HIZ001>003-006>008-012-013-017-019-020-151445- /O.CON.PHFO.SU.W.0002.000000T0000Z-210115T1600Z/ Niihau-Kauai Windward-Kauai Leeward-Waianae Coast- Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward- Maui Windward West-Maui Central Valley-Windward Haleakala- 338 PM HST Thu Jan 14 2021 ...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 AM HST FRIDAY... * WHAT...Dangerous surf of 25 to 30 feet along north facing shores and 15 to 20 feet along west facing shores. * WHERE...North and west facing shores of Niihau, Kauai, Oahu, Molokai and north facing shores of Maui. * WHEN...Until 6 AM HST Friday. * IMPACTS...High. Expect ocean water occasionally sweeping across portions of beaches, very strong breaking waves, and strong currents. Breaking waves may occasionally impact harbors making navigating the harbor channels dangerous. Anyone entering the water could face significant injury or death. Coastal flooding is possible. * ADDITIONAL DETAILS...The combination of large surf coinciding with peak monthly high tides may worsen beach erosion along shorelines exposed to north swell during the early morning hours. 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. && $$ HIZ025-151445- /O.CON.PHFO.SU.Y.0005.000000T0000Z-210115T1600Z/ Big Island North and East- 338 PM HST Thu Jan 14 2021 ...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 AM HST FRIDAY... * WHAT...Surf of 12 to 16 feet along north facing shores of the Big Island. * WHERE...North facing shores of the Big Island. * WHEN...Until 6 AM HST Friday. * IMPACTS...Moderate. Expect strong breaking waves, shore break, and strong longshore and rip currents making swimming difficult and dangerous. * ADDITIONAL DETAILS...The combination of large surf coinciding with peak monthly high tides may worsen beach erosion along shorelines exposed to north swell during the early morning hours. PRECAUTIONARY/PREPAREDNESS ACTIONS... Beachgoers, swimmers, and surfers should heed all advice given by ocean safety officials and exercise caution. && $$
319 WHHW40 PHFO 151322 CFWHFO Coastal Hazard Message National Weather Service Honolulu HI 322 AM HST Fri Jan 15 2021 ...HIGH SURF ADVISORY FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU MOLOKAI AND NORTH FACING SHORES OF MAUI AND BIG ISLAND... .The current northwest swell will slowly trend lower today. Surf heights will remain at advisory levels today for north and west facing shores of the smaller islands, including north facing shores of Maui and the Big Island. HIZ001>003-006>008-012-013-017-019-020-160230- /O.CAN.PHFO.SU.W.0002.000000T0000Z-210115T1600Z/ /O.EXB.PHFO.SU.Y.0005.000000T0000Z-210116T0400Z/ 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 AM HST Fri Jan 15 2021 ...HIGH SURF ADVISORY IN EFFECT UNTIL 6 PM HST THIS EVENING... ...HIGH SURF WARNING IS CANCELLED... * WHAT...Surf of 10 to 15 feet along north facing shores and 8 to 12 for 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. && $$ HIZ025-160230- /O.EXT.PHFO.SU.Y.0005.000000T0000Z-210116T0400Z/ Big Island North and East- 322 AM HST Fri Jan 15 2021 ...HIGH SURF ADVISORY NOW IN EFFECT UNTIL 6 PM HST THIS EVENING... * WHAT...Surf of 10 to 15 feet along north facing shores. * WHERE...North facing shores of the Big Island. * WHEN...Until 6 PM HST this evening. * IMPACTS...Moderate. Expect strong breaking waves, shore break, and strong longshore and rip currents making swimming difficult and dangerous. PRECAUTIONARY/PREPAREDNESS ACTIONS... Beachgoers, swimmers, and surfers should heed all advice given by ocean safety officials and exercise caution. && $$
897 WHHW40 PHFO 151356 CCA CFWHFO Coastal Hazard Message...CORRECTED National Weather Service Honolulu HI 356 AM HST Fri Jan 15 2021 ...HIGH SURF ADVISORY FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU MOLOKAI AND NORTH FACING SHORES OF MAUI AND BIG ISLAND... .The current northwest swell will slowly trend lower today. Surf heights will remain at advisory levels today for north and west facing shores of the smaller islands, including north facing shores of Maui and the Big Island. HIZ001>003-006>008-012-013-017-019-020-160230- /O.CAN.PHFO.SU.W.0002.000000T0000Z-210115T1600Z/ /O.COR.PHFO.SU.Y.0005.000000T0000Z-210116T0400Z/ Niihau-Kauai Windward-Kauai Leeward-Waianae Coast- Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward- Maui Windward West-Maui Central Valley-Windward Haleakala- 356 AM HST Fri Jan 15 2021 ...HIGH SURF ADVISORY IN EFFECT UNTIL 6 PM HST THIS EVENING... ...HIGH SURF WARNING IS CANCELLED... * WHAT...Surf of 15 to 20 feet this morning along north facing shores, lowering to 10 to 15 feet this afternoon. Surf 10 to 15 feet this morning along west facing shores, lowering to 8 to 12 feet this afternoon. * 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. && $$ HIZ025-160230- /O.EXT.PHFO.SU.Y.0005.000000T0000Z-210116T0400Z/ Big Island North and East- 356 AM HST Fri Jan 15 2021 ...HIGH SURF ADVISORY NOW IN EFFECT UNTIL 6 PM HST THIS EVENING... * WHAT...Surf of 10 to 15 feet along north facing shores. * WHERE...North facing shores of the Big Island. * WHEN...Until 6 PM HST this evening. * IMPACTS...Moderate. Expect strong breaking waves, shore break, and strong longshore and rip currents making swimming difficult and dangerous. PRECAUTIONARY/PREPAREDNESS ACTIONS... Beachgoers, swimmers, and surfers should heed all advice given by ocean safety officials and exercise caution. && $$
924 WHHW40 PHFO 152000 CFWHFO Coastal Hazard Message National Weather Service Honolulu HI 1000 AM HST Fri Jan 15 2021 ...HIGH SURF ADVISORY FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU MOLOKAI AND NORTH FACING SHORES OF MAUI AND BIG ISLAND... ...HIGH SURF WARNING IN EFFECT FROM TONIGHT FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU MOLOKAI AND NORTH FACING SHORES OF MAUI.... .The current north-northwest swell will slowly trend lower today. The largest northwest swell of the season thus far will rapidly fill in tonight and build through Saturday. This swell will likely peak Saturday then steadily decline through Sunday. Another warning level swell is expected on Monday. HIZ001>003-006>008-012-013-017-019-020-160900- /O.NEW.PHFO.SU.W.0003.210116T0400Z-210117T1600Z/ /O.CON.PHFO.SU.Y.0005.000000T0000Z-210116T0400Z/ Niihau-Kauai Windward-Kauai Leeward-Waianae Coast- Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward- Maui Windward West-Maui Central Valley-Windward Haleakala- 1000 AM HST Fri Jan 15 2021 ...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 PM HST THIS EVENING... ...HIGH SURF WARNING IN EFFECT FROM 6 PM THIS EVENING TO 6 AM HST SUNDAY... * WHAT...Surf of 15 to 20 feet this morning along north facing shores, lowering to 10 to 15 feet this evening, then rapidly building to 40 to 50 feet Saturday. Surf 10 to 15 feet this morning along west facing shores, lowering to 8 to 12 feet this evening, then rapidly building to 25 to 35 feet Saturday. * WHERE...North and west facing shores of Niihau, Kauai, Oahu, Molokai and north facing shores of Maui. * WHEN...For the High Surf Warning, from 6 PM this evening to 6 AM HST Sunday. For the High Surf Advisory, until 6 PM HST this evening. * 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. && $$ HIZ025-160400- /O.CON.PHFO.SU.Y.0005.000000T0000Z-210116T0400Z/ Big Island North and East- 1000 AM HST Fri Jan 15 2021 ...HIGH SURF ADVISORY REMAINS IN EFFECT UNTIL 6 PM HST THIS EVENING... * WHAT...Surf of 16 to 24 feet along north facing shores. * WHERE...North facing shores of Big Island. * WHEN...Until 6 PM HST this evening. * IMPACTS...Moderate. Expect strong breaking waves, shore break, and strong longshore and rip currents making swimming difficult and dangerous. PRECAUTIONARY/PREPAREDNESS ACTIONS... Beachgoers, swimmers, and surfers should heed all advice given by ocean safety officials and exercise caution. && $$
288 WHHW40 PHFO 160148 CFWHFO Coastal Hazard Message National Weather Service Honolulu HI 348 PM HST Fri Jan 15 2021 ...HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU MOLOKAI AND NORTH FACING SHORES OF MAUI.... ...HIGH SURF ADVISORY FOR NORTH FACING SHORES OF THE BIG ISLAND THROUGH TONIGHT... .The current north-northwest swell has dropped across most areas, but continues to linger around the Big Island. The largest northwest swell of the season thus far will rapidly fill in tonight and peak on Saturday. Surf of 40 to 50 feet with occasional high sets are expected along select north facing exposures. The combination of giant surf and the recent spring tides will likely cause waves to overtop lower roadways that are closer to the shoreline and may cause impacts to coastal properties and infrastructures. HIZ001>003-006>008-012-013-017-019-020-161500- /O.CAN.PHFO.SU.Y.0005.000000T0000Z-210116T0400Z/ /O.EXT.PHFO.SU.W.0003.210116T0148Z-210117T1600Z/ Niihau-Kauai Windward-Kauai Leeward-Waianae Coast- Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward- Maui Windward West-Maui Central Valley-Windward Haleakala- 348 PM HST Fri Jan 15 2021 ...HIGH SURF WARNING NOW IN EFFECT UNTIL 6 AM HST SUNDAY... ...HIGH SURF ADVISORY IS CANCELLED... * WHAT...Surf rapidly building to 40 to 50 feet tonight through Saturday along north facing shores. Surf rapidly building to 25 to 35 feet tonight through Saturday along west facing shores. * WHERE...North and west facing shores of Niihau, Kauai, Oahu, Molokai and north facing shores of Maui. * WHEN...Until 6 AM HST Sunday. * Very High...Expect ocean water surging and sweeping across beaches, coastal benches, and lava flows creating the potential for impacts to coastal properties and infrastructure, including roadways. Powerful longshore and rip currents will be present at most beaches. Large breaking waves and strong currents may impact harbor entrances and channels causing challenging boat handling. 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. && $$ HIZ025-161500- /O.EXT.PHFO.SU.Y.0005.000000T0000Z-210116T1600Z/ Big Island North and East- 348 PM HST Fri Jan 15 2021 ...HIGH SURF ADVISORY NOW IN EFFECT UNTIL 6 AM HST SATURDAY... * WHAT...Surf of 12 to 18 feet lowering to 10 to 14 along north facing shores late tonight. * WHERE...North facing shores of the Big Island. * WHEN...Until 6 AM HST Saturday. * IMPACTS...Moderate. Expect strong breaking waves, shore break, and strong longshore and rip currents making swimming difficult and dangerous. PRECAUTIONARY/PREPAREDNESS ACTIONS... Beachgoers, swimmers, and surfers should heed all advice given by ocean safety officials and exercise caution. && $$ Kino
118 WHHW40 PHFO 161326 CFWHFO Coastal Hazard Message National Weather Service Honolulu HI 326 AM HST Sat Jan 16 2021 ...HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU MOLOKAI AND NORTH FACING SHORES OF MAUI.... ...HIGH SURF ADVISORY FOR NORTH AND WEST FACING SHORES OF THE BIG ISLAND STARTING NOON TODAY... .A giant northwest swell will build today, peaking on Kauai during the late morning, on Oahu shortly after midday, and mid- to late- afternoon on Maui. Some of the swell's energy is expected to reach portions of the Big Island later in the day, peaking tonight. A gradual decrease in wave heights is expected on Sunday, but another large swell is expected to arrive by Monday. HIZ025-170230- /O.CAN.PHFO.SU.Y.0005.000000T0000Z-210116T1600Z/ /O.NEW.PHFO.SU.Y.0006.210116T2200Z-210118T0400Z/ Big Island North and East- 326 AM HST Sat Jan 16 2021 ...HIGH SURF ADVISORY IN EFFECT FROM NOON TODAY TO 6 PM HST SUNDAY... * WHAT...Surf of 12 to 16 feet. * WHERE...North facing shores of the Big Island. * WHEN...From noon today to 6 PM HST Sunday. * 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 and seek ocean recreation areas best suited for your abilities. && $$ HIZ009-170230- /O.EXA.PHFO.SU.W.0003.000000T0000Z-210117T1600Z/ Olomana- 326 AM HST Sat Jan 16 2021 ...HIGH SURF WARNING IN EFFECT UNTIL 6 AM HST SUNDAY... * WHAT...Surf of 30 to 40 feet. * WHERE...North facing shores of east Oahu. * WHEN...Until 6 AM HST Sunday. * IMPACTS...Very High. Expect ocean water surging and sweeping across beaches, coastal benches, and lava flows creating the potential for impacts to coastal properties and infrastructure, including roadways. Powerful longshore and rip currents will be present at most beaches. Large breaking waves and strong currents may impact harbor entrances and channels causing challenging boat handling. PRECAUTIONARY/PREPAREDNESS ACTIONS... Large, breaking surf, significant shorebreak, and dangerous currents make entering the water very hazardous. Anyone entering the water could face significant injury or death. && $$ HIZ001>003-006>008-012-013-017-019-020-170230- /O.CON.PHFO.SU.W.0003.000000T0000Z-210117T1600Z/ Niihau-Kauai Windward-Kauai Leeward-Waianae Coast- Oahu North Shore-Oahu Koolau-Molokai Windward-Molokai Leeward- Maui Windward West-Maui Central Valley-Windward Haleakala- 326 AM HST Sat Jan 16 2021 ...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 AM HST SUNDAY... * WHAT...Surf 40 to 50 feet along north facing shores, and 25 to 35 feet along west facing shores. * WHERE...North and west facing shores of Niihau, Kauai, Oahu and Molokai, and north facing shores of Maui. * WHEN...Until 6 AM HST Sunday. * IMPACTS...Very High...Expect ocean water surging and sweeping across beaches, coastal benches, and lava flows creating the potential for impacts to coastal properties and infrastructure, including roadways. Powerful longshore and rip currents will be present at most beaches. Large breaking waves and strong currents may impact harbor entrances and channels causing challenging boat handling. 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. && $$ HIZ023-026-170230- /O.NEW.PHFO.SU.Y.0006.210116T2200Z-210118T0400Z/ Kona-Kohala- 326 AM HST Sat Jan 16 2021 ...HIGH SURF ADVISORY IN EFFECT FROM NOON TODAY TO 6 PM HST SUNDAY... * WHAT...Surf 6 to 10 feet. * WHERE...West facing shores of the Big Island. * WHEN...From noon today to 6 PM HST Sunday. * IMPACTS...Moderate. Expect strong breaking waves, shore break, and strong longshore and rip currents making swimming difficult and dangerous. PRECAUTIONARY/PREPAREDNESS ACTIONS... Beachgoers, swimmers, and surfers should heed all advice given by ocean safety officials and exercise caution. Know your limits and seek ocean recreation areas best suited for your abilities. && $$ Birchard
What forecasters said that day
The local office's own words before this high surf advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Honolulu, HI wrote its last area forecast discussion before this high surf advisory went out at Jan 13, 8:59 PM HST, 6 hours 45 minutes earlier.
Area forecast discussion, Jan 13, 8:59 PM HST, 6 hours 45 minutes before
Area Forecast Discussion National Weather Service Honolulu HI 859 PM HST Wed Jan 13 2021 .SYNOPSIS... A weak front will stall out and dissipate across the central islands late tonight and Thursday, with an increase in showers expected near the front. A second front is expected to approach from the northwest Thursday night and Friday, then stall just northwest of Kauai Friday night and Saturday. A third and stronger front is forecast to move through the area Sunday into early next week, potentially bringing some heavy rainfall to portions of the island chain. && .DISCUSSION... Currently at the surface, a weakening front has just cleared Oahu, and is approaching Molokai from the north. Meanwhile, a 1019 mb high is centered around 300 miles north-northwest of Kauai. Infrared satellite imagery shows partly to mostly cloudy skies over Kauai and Oahu, with clear to partly cloudy conditions over most of Maui County and the Big Island, with the exception of leeward Big Island where mostly cloudy skies prevail. Radar imagery shows scattered to numerous showers in close proximity to the front, with only a few isolated showers further displaced from the front, although shower coverage is a bit higher over leeward Big Island. Main forecast concern revolves around the potential for unsettled weather late in the weekend through early next week. Tonight and Thursday... The front is expected to push southeastward into Maui County tonight, then slowly dissipate on Thursday, as the high north of the islands builds rapidly eastward. Moderate to breezy northerly winds behind the front, will shift around to the northeast at moderate speeds across the entire island chain later tonight. Moderate easterly trades are expected for Thursday, although the approach of the next in a series of fronts may ease the trades enough over the western islands Thursday afternoon to allow for localized sea breezes. Scattered to numerous showers are expected in close proximity to the front tonight, with a drier and more typical windward/mauka focused shower pattern expected on Thursday. Thursday night through Saturday... The next front will approach from the northwest Thursday night and Friday, then stall out and gradually dissipate around 100 miles northwest of Kauai Friday night and Saturday. Light and variable winds are expected to persist over the western islands during this time, with overnight land breezes and daytime sea breezes. Meanwhile, light to moderate east to southeast winds should prevail over the eastern end of the state. Fairly dry weather is expected to continue through the period statewide, with no significant rainfall expected. Saturday night through next Wednesday... Forecast uncertainty increases considerably late in the weekend through the first half of next week, as model consensus and individual model run to run continuity remain poor. What the models do agree upon however, is that another cold front will approach and move into the islands late in the weekend. What they disagree on is the progressiveness of the front, with the GFS showing an island clearing frontal passage, while the ECMWF hangs the front up over the island chain. There is the potential that a very wet pattern could set up across at least portions of the state Sunday through early next week, with heavy rainfall and thunderstorms not out of the question. Given the uncertainty, will follow a blended forecast approach until details become more clear. This will result in keeping rainfall in the forecast statewide through the entire extended period. && .AVIATION... The cloud band associated with a front has reached Oahu. Radar shows a line of showers, marking the front, in the Kaiwi Channel, creeping toward Molokai. Radar is also showing scattered showers mainly over the Koolau's and windward Oahu, and isolated showers around Molokai and Lanai. Some of these clouds and showers will advance to Maui in the next couple of hours, but that is as far as they will get, as the cloud band appears to be stalling and falling apart across Kauai and Oahu. Surface observations indicate that there are isolated pockets of MVFR ceilings at around 3k feet on Oahu and Kauai. The showers around Kailua-Kona Big Island and adjacent waters will gradually dissipate by around midnight. Otherwise, mostly clear skies are on tap for the Big Island for the rest of the night and into Thursday morning. The tops of the showers are mainly 10k feet with isolated higher tops to 15k feet in the heavier showers. There is an AIRMET Tango for high level turbulence between FL320/420 over the main Hawaiian Islands. Expect this AIRMET to be lowered by 16z. There are no other AIRMETs in effect and none are expected for the rest of tonight. && .MARINE... A cold front near Oahu will continue to weaken and stall out across the central islands late tonight and Thursday. Moderate to fresh northeast to east trade winds will briefly return on Thursday as a high pressure system passes by north of the island chain. Wind directions will then veer towards the southeast and weaken from Thursday night to Friday ahead of another cold front approaching the islands from the northwest. A Small Craft Advisory (SCA) remains in effect for waters near Kauai due to strong northerly winds behind the front this evening. A large northwest swell will move into the state tonight and Thursday with 10 to 15 foot seas spreading out over most of our exposed coastal waters and channels. The SCA will expand to cover areas that are exposed to this northwest swell with SCA conditions lasting into Friday. The current northwest swell (300-320 direction) will subside this evening as a new northwest swell (320-340 direction) builds into the region. This new northwest swell will peak above High Surf Warning levels, the Wave Watch III model forecast shows swell heights building to around 17 ft 15 sec on Thursday, then slowly lowering through Thursday night. Warning level surf on Thursday will decrease to High Surf Advisory levels by Friday. A brief overlapping northerly swell (350-360 direction) will also arrive Thursday night, peaking on Friday around 6 to 7 ft. An extra large northwest swell (310-330 direction) will arrive by Friday evening, quickly building to 20 ft 20 sec by Saturday morning according to the Wave Watch III forecast at the Waimea Buoy. These large swell heights will produce surf well above High Surf Warning thresholds, holding through Saturday, and then slowly lowering from Saturday night through Sunday. Surf will remain well above High Surf Warning levels through the weekend. The northwest swell event this weekend has the potential to produce the largest surf of the season along exposed north and west facing shores. Surf along south and east facing shores will remain small through early next week. A combination of large surf this week coinciding with peak monthly high tides may worsen beach erosion along shorelines exposed to north and west swells during the early morning hours. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Warning from midnight tonight to 6 PM HST Thursday for Niihau-Kauai Windward-Kauai Leeward-Waianae Coast-Oahu North Shore-Oahu Koolau-Molokai-Maui Leeward West-Maui Central Valley- Windward Haleakala. Small Craft Advisory from midnight tonight to 6 PM HST Thursday for Kauai Northwest Waters-Oahu Windward Waters-Kaiwi Channel- Maui County Windward Waters-Big Island Windward Waters. Small Craft Advisory until 6 PM HST Thursday for Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel. && DISCUSSION...Jelsema AVIATION...H Lau MARINE...Morrison/Bohlin
The office that day
Everything else NWS Honolulu, HI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 13, 3:07 PM HST | High Surf Warning | HFO | Honolulu, Kauai, Kalawao | 36 hr |
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.