SURF ZONE FORECAST
NATIONAL WEATHER SERVICE HONOLULU HI
700 PM HST FRI NOV 6 2009
OAHU-
700 PM HST FRI NOV 6 2009
Surf along north facing shores will increase to heights of 6 to 10 feet Saturday.
Surf along west facing shores will be 3 to 5 feet Saturday.
Surf along south facing shores will be 3 to 6 feet through Saturday.
Surf along east facing shores will remain 2 to 4 feet through Saturday.
Outlook through Thursday Nov 12: surf may approach advisory levels on the north and east facing shores Wednesday night and Thursday as a large swell arrives from the north northeast.
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.
COLLABORATIVE NEARSHORE SWELL AND WIND FORECAST FOR OAHU 
NWS/NCDDC HONOLULU HI
300 PM HST FRI NOV 6 2009
This collaborative forecast will be updated Monday through Friday at 300 pm when Pat Caldwell is available. When Pat Caldwell is not available, the latest collaborative forecast will remain posted for 4 days.
| FORECAST DATE | SWL HGT | DMNT DIR | DMNT PD | H 1/3 | H 1/10 | HGT TEND | PROB | WIND SPD | WIND DIR | SPD TEND |
| 1PM 11/06 | 4 | NNW | 11 | 6 | 8 | DOWN | 13-19 | ENE | SAME | |
| 7 | ENE | 7 | 2 | 4 | DOWN | |||||
| 3 | SSW | 14 | 5 | 7 | SAME | |||||
| SAT 11/07 | 5 | NNW | 15 | 8 | 10 | SAME | HIGH | 13-19 | E | SAME |
| 7 | ENE | 7 | 2 | 4 | SAME | MED | ||||
| 3 | SSW | 14 | 5 | 7 | SAME | MED | ||||
| SUN 11/08 | 4 | N | 13 | 6 | 8 | DOWN | MED | 13-19 | E | SAME |
| 7 | ENE | 7 | 2 | 4 | SAME | MED | ||||
| 2 | SSW | 13 | 2 | 4 | DOWN | MED | ||||
| MON 11/09 | 4 | N | 11 | 6 | 8 | SAME | LOW | 13-19 | ENE | SAME |
| 7 | ENE | 7 | 2 | 4 | SAME | MED | ||||
| 2 | SSW | 12 | 2 | 4 | SAME | LOW | ||||
| TUE 11/10 | 3 | NNE | 10 | 4 | 6 | DOWN | LOW | 13-19 | ENE | SAME |
| 7 | ENE | 7 | 2 | 4 | SAME | LOW | ||||
| 2 | SSW | 15 | 2 | 4 | UP | LOW | ||||
| WED 11/11 | 4 | N | 13 | 6 | 8 | UP | LOW | 13-19 | ENE | SAME |
| 7 | ENE | 7 | 2 | 4 | SAME | LOW | ||||
| 2 | SSW | 14 | 2 | 4 | SAME | LOW |
LEGEND:
| SWL HGT | OPEN OCEAN SWELL HEIGHT MEASURED FROM TROUGH TO CREST IN FEET LOCATED 20 NAUTICAL MILES OFFSHORE |
| DMNT DIR | DOMINANT DIRECTION TYPICALLY +/-10 DEGREES IN 16 COMPASS POINTS |
| 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 SURF ZONE |
| 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 LOCATED 20 NAUTICAL MILES OFFSHORE |
| WIND DIR | WIND DIRECTION IN 16 COMPASS POINTS |
| SPD TEND | WIND SPEED TENDENCY (VALID VALUES: UP/DOWN/SAME) |
Compass & Swell Shadow Lines for Hawaii
Surf heights will vary between different beaches and at the same beach at different break areas.
DISCUSSION:
Summary: near high southerly swell to last into Saturday. Moderate northerly swell for the weekend.
Detailed: mid Friday on southern shores has moderate to occasionally quasi-high breakers from 185-200 degrees. Similar heights expected on Saturday.
An active austral spring pattern has set up near New Zealand making local surf above average, which is near nil from southern hemisphere sources in November. The pattern continues into the long range.
A week ago this past Wednesday into Thursday, severe gales SE of New Zealand generated long period swell aimed at Hawaii in the 190-200 degree band. This energy arrived locally on this past Wednesday and rose on Thursday.
Last Friday east of the north island of New Zealand, a new low pressure formed with gales in the 185-200 degree band reaching to within 3000 nm of Hawaii. Swell from the first system were given an extra push from the second system. The result is near high conditions locally on Friday. With the long travel distance, the swell trains become dispersed, or spread in groups of similar wave periods over wide areas. This should mean slow changes to the local pattern. Buoy 51002 shows energy in the 13-16 second band staying fairly steady on Friday morning. Most likely, local surf will hold the same on Saturday, with a downward trend late Saturday into Sunday from the same direction. Lingering small surf is possible on Monday.
Another extratropical cyclone passed SE of New Zealand early this week, though aiming more at targets east of Hawaii. Angular spreading should bring in at least small breakers next Tuesday into Wednesday from 180-200 degrees.
Mid Friday on northern shores has sub-moderate breakers from 340-020 degrees with 9-12 second periods. This was associated with near gales north of the state mid week. This episode is expected to lower overnight as a new episode arrives.
The north Pacific jet stream has had a blocking pattern, or ridge, near the dateline and trough in the gulf of Alaska. This is giving dominant swell from NNW to NNE. More of the same is expected through next week.
A short-wave in the jet stream rounded the ridge and amplified on Tuesday as it moved east of the longitude of Hawaii, 160°W. At the surface, severe gales in an area over 1500 nm set up just east of the dateline on Tuesday, aimed near to just east of Hawaii. By Wednesday, the system strengthened and broadened, yet left the Hawaii swell window.
Long period swell of 15-17 seconds is due locally overnight, with surf in the moderate category on Saturday from 345-360 degrees. Heights should slowly lower Sunday into Tuesday, with added energy from 000-030 due to angular spreading from the massive gulf of Alaska source, with at least small breakers.
Models show a similar pattern with an amplifying short-wave near 160°W on Sunday as it tracks east. At the surface, winds are expected to be much weaker for the fetch aimed at or just east of Hawaii, leaning toward marginal gales in an area 1500 nm out on Sunday. This could give a near moderate episode for Wednesday from 350-010 degrees.
Mid Friday on eastern shores has small to moderate breakers under moderate to fresh trades. See the latest NWS state weather forecast discussion for explanations and caveats to the Friday five-day wind forecast. Similar surf is expected into early next week.
Into the long range, windswell to at least moderate levels from 30-90 degrees mid next week toward the weekend. No suggestions of surf from WNW to NW later next week. Dominant direction from NNW to NNE expected to continue into next weekend. Mix in models gives best wind estimate to mid November climatology, moderate to fresh trades.
In the southern hemisphere, a long wave trough is setting up east of New Zealand with a series of short-waves modelled to push through, each associated with a surface low pressure SE to E of New Zealand. This should give well above November south shore averages for the week starting November 15 out about a week.
Long range forecasts are subject to high uncertainty.
This collaborative forecast will resume on Monday, November 9.
This forecast was produced through the collaborative efforts of NWS and NCDDC. Please send suggestions to w-hfo.webmaster@noaa.gov 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 CP/Pat Caldwell, Pacific/Hawaii Liaison Office, NCDDC
Additional Resources:
| Waimea Buoy | Kailua Buoy | Lanai Buoy | Kilo Nalu | Buoy 51001 | Buoy 51101 | Buoy 51000 | Buoy 51100 | Buoy 51002 | Buoy 51003 | Buoy 51004 |


