HIGH SURF ADVISORY IN EFFECT FOR EAST FACING SHORES
Surf along north facing shores will be 3 to 5 feet today, decreasing to 2 to 4 feet on Monday.
Surf along west facing shores will be 3 feet or less through Monday.
Surf along east facing shores will be 5 to 8 feet today, decreasing to 3 to 6 feet on Monday.
Surf along south facing shores will be 1 to 3 feet today, increasing to 3 to 5 feet on Monday.
Outlook through Sunday October 30: the elevated short period trade wind swell is expected to dip below advisory level by this evening. A new northwest swell of moderate height is expected to reach our north and west facing shores Tuesday morning, peak Tuesday night followed by a gradual decline through Wednesday. A small south swell will hit our south facing beaches late this afternoon, peak Monday, and begin declining Monday night.
Surf heights are forecast heights of the face or front of waves. The surf forecast is based on the significant wave height, the average height of the one third largest waves, in the zone of maximum refraction. Some waves may be more than twice as high as the significant wave height. Expect to encounter rip currents in or near any surf zone.
About Collaborative Surf
THIS COLLABORATIVE FORECAST WILL BE UPDATED MONDAY THROUGH FRIDAY AT
300 PM WHEN PAT CALDWELL IS AVAILABLE/
Collaborative Surf Table
Collaborative Surf Table Legend
|SWL HGT||OPEN OCEAN SWELL HEIGHT MEASURED FROM TROUGH TO CRESTIN FEET LOCATED 20 NAUTICAL MILES OFFSHORE|
|DMNT DIR||DOMINANT DIRECTION TYPICALLY +/-10 DEGREES IN 16 COMPASSPOINTS|
|DMNT PD||DOMINANT PERIOD IN SECONDS|
|H1/3||SIGNIFICANT WAVE HEIGHT IN THE SURF ZONE|
|H1/10||AVERAGE HEIGHT OF THE HIGHEST ONE-TENTH WAVES IN THE SURFZONE|
|HGT TEND||HEIGHT TENDENCY OF SWELL (VALID VALUES: UP/DOWN/SAME)|
|PROB||PROBABILITY OF OCCURRENCE (VALID VALUES: HIGH/MED/LOW)|
|WIND SPD||OPEN WATER WIND SPEED MEASURED IN KNOTS LOCATED20 NAUTICAL MILES OFFSHORE|
|WIND DIR||WIND DIRECTION IN 16 COMPASS POINTS|
|SPD TEND||WIND SPEED TENDENCY (VALID VALUES: UP/DOWN/SAME)|
SURF HEIGHTS WILL VARY BETWEEN DIFFERENT BEACHES AND AT THE SAME
BEACH AT DIFFERENT BREAK AREAS.
Collaborative Surf Discussion
Discussion: summary: Shorter period surf over the weekend and long-period WNW Tuesday.
Detailed: Mid Friday on has declining breakers from 340-010 degrees with 10-13 second periods at levels below the October average. Surf should remain below average on Saturday.
A large area of low pressure in the gulf of Alaska had near gales at the eastern edge of the Hawaiian swell window 10/18-20. Shorter period swell of 10-13 seconds from this source is arriving Friday 10/21 and should slowly trend down Saturday 10/22 from 340-010 degrees.
A stronger, compact low pressure within the larger field of low pressure in the gulf of Alaska gained gale status SW of Kodiak island 10/19. It tracked SE aiming highest seas well E of Hawaii. Angular spreading should bring below average surf locally picking up Saturday and dropping Sunday from 000-020 degrees.
Further west, a low pressure deepened to 966 mb east of the kuril island 10/20-21. The system has occluded, so movement is slowing. It is modelled to drift eastward to near 165°E early Saturday before shifting north while steadily weakening.
Ascat satellite Thursday night showed a large area of severe gale to storm-force winds just east of the Kuril Islands. Wave models show seas building to a maximum early Saturday above 25 feet at the closest reach to Hawaii of about 2200 nm.
Long-period forerunners are due near sundown Monday. The event should be filled in by Tuesday morning from 305-310 degrees. It should steadily grow to levels above the October average. The episode is expected to peak late Tuesday, and fall to the average on Wednesday from 305-315 degrees.
Mid Friday on has rough, rising breakers from windswell. Heights have climbed above the trade windswell average. Size should continue to rise Saturday from 30-80 degrees.
See the latest NWS state forecast discussion for an explanation of local winds and weather.
The 1032 mb surface high pressure north of Hawaii 10/20-21 has set up a long fetch of fresh to strong breezes over Hawaii out about 600 nm to the ENE to NE. There was a ribbon of near gale breezes along 30°N 10/19 as seen in the ascat data. Pacioos/cdip mokapu buoy off east Oahu shows a steady rise in the longer end of the wave period spectrum on Friday 10/21 from 30-60 degrees. Longer wave periods allow more surf size.
Models show a maximum to the winds late Saturday over and upstream of Hawaii, that should coincide with the peak of the windswell locally late Saturday into early Sunday.
Models show a weakening to the upstream winds east of 155°W between 20-30°N late Sunday into Monday. With the shorter fetch, the local dominant wave period should trend down Monday to Wednesday. Breakers are expected to drop near to below average by Tuesday and below average Wednesday from 30-80 degrees.
Mid Friday on has near flat conditions. Exposures to eastern windswell should have surf over the weekend.
A gale low pressure moved slowly east along 45°S to the east of New Zealand to south of French Polynesia 10/17-20. The winds were magnitude deficient, so only a small event is expected locally. It should pick up Monday from 170-190 degrees, peak late Monday, then linger into Wednesday.
Into the long range, no swell beyond tiny is expected from the southern hemisphere 10/27-29.
In the northern hemisphere, gales modelled south of the Aleutians west to near the dateline 10/25-26 could bring a near average event locally from 310-320 degrees 10/29.
Shorter period N to NE swell is suggested in models for 10/27-29.
Long range forecasts are subject to high uncertainty.
This collaborative forecast will resume on Tuesday, October 25.
This forecast was produced through the collaborative efforts of NWS and ncei. Please send suggestions to email@example.com or call the Warning Coordination Meteorologist at 808-973-5275.
Additional resources: see /in lowercase/ http://www.prh.noaa.gov/hnl/pages/marine.php.
NWS FORECASTER AND NCEI PAT CALDWELL