No high surf advisory or warnings.
Surf along north facing shores will be 3 to 5 feet tonight, lowering to 1 to 3 feet Thursday.
Surf along west facing shores will be 1 to 3 feet through Thursday.
Surf along east facing shores will be 3 to 5 feet tonight, lowering to 2 to 4 feet Thursday.
Surf along south facing shores will be 1 to 3 feet through Thursday.
Outlook through Wednesday October 05: choppy short-period surf will continue along east facing shores through the week and may slightly increase over the upcoming weekend due to strengthening trade winds. A small northwest swell will be possible Tuesday of next week.
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: Trade windswell.
Detailed: Mid Wednesday on northern shores has small, short-period breakers from 355-030 degrees. Heights are declining.
Mid latitude extra-tropical cyclone sources in the north Pacific have been weak and far away from Hawaii over the past week into this week. This has given the summery surf pattern locally.
Surface high pressure produced the recent short-period event from with NNW to NNE. Fresh to strong winds on the north side of a shearline north of 30°N to the NW to NE of Hawaii 9/25-27 generated the waves. The pacioos/cdip Waimea and mokapu buoys off Oahu show a downward trend 9/28 in the 8-12 second wave period band as the dominant direction slowly veers on the compass. Ascat satellite 9/27 still showed enhanced winds to the NE of Hawaii beyond 500 nm that could keep a short-period bump from 30-50 degrees Thursday into Friday for select exposures prone to focusing N to NE wave directions.
The minor low pressure near the dateline 9/25-27 was too weak to expect surf beyond tiny. Wave watch iii only gives 1 feet at 10 seconds from 310 degrees for Friday 9/30.
Mid Wednesday on southern shores has minimal conditions, well below the active season, March to October, average. Similar surf is expected on Thursday.
A broad area of low pressure SSE of French Polynesia 9/22-24 moved steadily east. Low odds for long-period swell locally starting Thursday 9/29 into Friday with 1 feet deep water swell with 17 second periods from 170 degrees. It should trend down into the weekend with heights below average.
Mid Wednesday on eastern shores has higher breakers for more northerly exposures from the source described above. Trade windswell from within 50-90 degrees is a notch below average.
See the latest NWS state forecast discussion regarding the lower and upper atmospheric features driving the local trend in winds and uncertainties in the forecast.
Windswell from 40-90 degrees should stay about the same into Friday. Freshening trades over and E to NE of Hawaii 9/29-10/1 should bring breakers from windswell back to the average for the weekend.
Tropical cyclone Ulika on 9/28 is in the Big Island shadow for Oahu, as well as being a compact system. Thus wave potential on Oahu is low. Models suggest a weakened, remnant feature enhancing trade winds to its north 10/1-2, that could keep short-period breakers near to a notch above average Monday 10/3 from 60-90 degrees, even as local winds are expected to decline.
Into the long range, easterly windswell should trend down 10/4-5.
Mid latitude regions S to SE of French Polynesia 9/26-28 have had some marginal gales, though aimed highest east of Hawaii. Background, low southerly swell should favor 160-190 degrees next week 10/4-8 with subtle ups and downs.
A weak low pressure near the dateline just south of the Aleutians 9/29-30 could give a small event locally from 315-325 degrees 10/4-5.
Long range forecasts are subject to high uncertainty.
This collaborative forecast will resume on Friday, September 30.
This forecast was produced through the collaborative efforts of NWS and ncei. Please send suggestions to firstname.lastname@example.org 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