HIGH SURF WARNING FOR EAST FACING SHORES
Surf along east facing shores will be 10 to 15 feet through Thursday. Surf along south facing shores will be 4 to 6 feet today, rising to 5 to 7 feet Thursday. Surf along west facing shores will be 2 to 4 feet today, rising to 3 to 5 feet Thursday. Surf along north facing shores will be 10 to 13 feet today, lowering to 6 to 9 feet Thursday.
Outlook through Tuesday September 8: the swell from tropical storm Ignacio will gradually shift from north northeast to northwest and subside over the next couple of days. A new long period swell from hurricane Jimena will keep surf elevated through Monday along east facing shores. A new south swell will fill in Thursday through Saturday and may generate advisory level surf along the south facing shores by Friday. Small west swell from typhoon Kilo will persist into the weekend. 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, at the locations of the largest breakers. 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 Discussion
Discussion: summary: Active pattern from north Pacific tropical cyclones and austral mid latitude cyclones. Detailed: Mid Wednesday on northern shores has above early September average surf, which is near 5 feet face peak face on the sets. Heights are expected to lower on Thursday. Tropical system Ignacio brought the surf up abruptly late Tuesday with a maximum overnight from 10-40 degrees. Heights are slowly lowering. Ignacio is weakening with north component to its track. This results in duration limited fetches for the quadrant aimed at Hawaii over the 330-350 degree band. Surf should drop to near the early September average by Friday, then linger below average over the weekend from within 330-350 degrees. Mid Wednesday on eastern shores has breakers well above the east side trade windswell average. Similar conditions are predicted for Thursday. More northerly exposures of the east side are receiving the Ignacio swell with a trend as described above. Hurricane Jimena swell is to make for an extended period of well above average surf. See the latest Central Pacific Hurricane Center products for details on Jimena. Jimena became a major hurricane last Friday 8/28 beyond 1200 nm ESE of Hawaii and maintained similar strength into the weekend as it tracked WNW. The pacioos/cdip buoy offshore Kailua, Oahu, shows a rise in the 16-22 second wave periods 9/2 from 85-90 degrees. As Jimena moved west to near 140°W 9/1, it became closer to the Oahu shadow created by the easternmost Hawaii islands. Wave watch iii, ww3, shows a decline in dominant wave period, which should give a slight lowering of surf by Friday, though still well above average. Thus surf is expected to lower a notch Thursday into Friday. Models show Jimena with more northward track starting 9/2, which will place Oahu fully into the swell window. With more proximity and no shadow, the surf is expected to trend up Saturday to Monday with a slow backing in direction from 90 to 70 degrees. With deep water swell energy of such magnitude as predicted by ww3 over the long weekend, significant coastal wave wash is expected during the higher tides, which will be near neap tide status, offsetting run-up potential somewhat with lower high tides. Mid Wednesday on western shores has small breakers. Similar surf is expected on Thursday though higher for more southerly exposures as described below. Typhoon Kilo near the dateline is moving west. Ww3 keeps low swell from 270-280 degrees passing the longitudes of Hawaii through the period. Shadowing by Niihau and Kauai on Oahu makes for greater error bars on the surf estimate and larger gradients of surf along any given coast depending on the degree of shadowing. Mid Wednesday on southern shores has slowly rising, long-period swell from 190-220 degrees. Breakers are near the March to October, seasonal average. Heights should be about the same with a slow upward trend on Thursday. The austral jet stream for longitudes east of New Zealand was split for much of August with a weaker subtropical branch and a zonal stronger branch further poleward than normal. This lead to below average conditions. The pattern changed late August with the stronger, more poleward portion shifting equatorward. More consistent average to above average conditions are expected during the first half of September. The first system was strongest in the Tasman sea 8/24 and weakened as it reached the Hawaii swell window SE of New Zealand 8/25-26. Pacioos/cdip Barbers Point buoy off SW Oahu shows an upward trend 9/2 in the 16-22 second bands from 190-220 degrees. This event should stay about the same on Thursday at heights near the seasonal average. Starting 8/26, a long wave jet stream trough formed south of French Polynesia with a broad area of winter-caliber low pressure at the surface. Severe gale to hurricane-force winds grew seas within 30-40 feet over a massive area within 160°E to 160°W and 55-65°S. Highest seas were aimed at the Americas, but with such a massive source, Hawaii is close enough to receive swell through angular spreading. Long period swell of 17-22 seconds is expected late Thursday into Friday, with an inconsistent build-up of the surf. The event should be filled in by late Friday from 180-190 degrees at levels above average. It should peak Saturday and drop on Sunday. Another low pressure formed SE of New Zealand 8/29. It tracked NE with gales and small pockets of severe gales over the 180-195 degree band. The primary fetch was aimed SE of Hawaii though a significant portion did point at Hawaii. The head of the fetch reach near 32°S, or about 3000 nm away by 8/31. Long period swell of 16-18 seconds are due locally mid Sunday from 180-195 degrees. It is expected to be filled in by mid Monday and peak late Monday at levels above average. Into the long range, southern shores should remain above average Tuesday 9/8 with a downward trend, dropping to near the average by 9/9. Models show another low pressure area east of New Zealand 9/5-8 that suggests above average SSW surf locally about a week later, or roughly starting 9/12. Jimena is predicted to remain at least tropical storm status into the long weekend with more northerly latitude, which should continue to back the dominant direction from ENE to NE 9/8-10 with a slow downward trend. Potential for typhoon Kilo and tropical system Ignacio will be monitored. Long range forecasts are subject to low confidence. This collaborative forecast will resume on Friday, September 4. This forecast was produced through the collaborative efforts of NWS and NCDDC. 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.
Collaborative Surf Table
SURF HEIGHTS WILL VARY BETWEEN DIFFERENT BEACHES AND AT THE SAME BEACH AT DIFFERENT BREAK AREAS.
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)|
NWS FORECASTER AND NCDDC PAT CALDWELL