FZHW50 PHFO 
SRFHFO
SURF ZONE FORECAST
NATIONAL WEATHER SERVICE HONOLULU HI
700 PM HST TUE FEB 9 2010
OAHU-
700 PM HST TUE FEB 9 2010
HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES
Surf along north facing shores will be 6 to 8 feet, rising rapidly by early Wednesday to near 25 feet, and as high as 30 feet on outer reefs.
Surf along west facing shores will be 3 to 6 feet, rising rapidly to 10 to 20 feet by early Wednesday.
Surf along east facing shores will be 1 to 3 feet through Wednesday.
Surf along south facing shores will be 2 to 4 feet, rising to 3 to 5 feet Wednesday.
Outlook through Monday Feb 15: surf will be at warning levels on north and west shores early Wednesday through Thursday. Surf will be lower Friday but still remain at advisory levels through the weekend. Surf along the south shore may reach the 8 foot advisory level Thursday.
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 MON FEB 8 2010
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 02/08 | 4 | WNW | 12 | 6 | 8 | SAME | 11-16 | ENE | SAME | |
| TUE 02/09 | 3 | WNW | 10 | 4 | 6 | DOWN | LOW | 7-10 | ENE | DOWN |
| 4 | NW | 15 | 6 | 8 | UP | LOW | ||||
| 2 | S | 13 | 2 | 4 | UP | LOW | ||||
| 3 | WNW | 20 | 6 | 8 | UP | LOW | ||||
| WED 02/10 | 11 | WNW | 17 | 24 | 30 | SAME | HIGH | 7-10 | NE | UP |
| 2 | S | 12 | 2 | 4 | SAME | LOW | ||||
| 2 | SSW | 20 | 4 | 6 | UP | LOW | ||||
| THU 02/11 | 12 | NW | 15 | 24 | 32 | UP | MED | 17-21 | NE | SAME |
| 7 | NE | 7 | 2 | 4 | UP | LOW | ||||
| 3 | S | 18 | 6 | 8 | SAME | LOW | ||||
| FRI 02/12 | 9 | NW | 14 | 16 | 22 | DOWN | LOW | 11-16 | ENE | DOWN |
| 5 | ENE | 7 | 2 | 4 | DOWN | LOW | ||||
| 3 | S | 15 | 4 | 6 | DOWN | LOW | ||||
| SAT 02/13 | 9 | NNW | 14 | 16 | 22 | UP | LOW | 11-16 | E | SAME |
| 5 | ENE | 7 | 2 | 4 | SAME | LOW | ||||
| 2 | S | 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: long-lived high surf episode beginning Tuesday night.
Detailed: mid Monday on northern shores has small breakers from 290-320 degrees. This is the tail end of the weekend episode and should trend down on Tuesday from this direction. The extratropical cyclone responsible for this event regained strength last Thursday into Friday just east of the Kuril Islands. Energy from this source out of 310-320 degrees should keep sub-moderate breakers on Tuesday.
The jet stream dipped much further south than normal late last week in the NW Pacific. A broad low pressure formed east of Tokyo and tracked east Friday into the weekend. A long fetch of severe-gales to storm-force winds in the 280-305 degree band developed, much longer lived, wider, and stronger than typical for the subtropical latitude bands. The head of the fetch reached to within about 1500 nm of Oahu Sunday afternoon. Seas were estimated above 35 feet over a large area. The center of low pressure tracked NNE starting late Sunday, as winds from this directional band decelerated.
Shadowing by Niihau and Kauai will greatly reduced local surf potential for Oahu, where gradients along the coast of surf size are likely to occur. Big error bars on height estimates due to the blockage.
Forerunners are expected Tuesday afternoon with a rapid rise after sundown. Surf from this directional band should peak on Wednesday in the extra-large category, meaning breakers on outer reefs, then slowly taper down into the weekend. The long, wide fetch and distant travel should make for a long-lived episode.
On Monday, the above mentioned low pressure area has occluded just west of the dateline as the center drifts NNE slowly. Two sources for surf are expected from the latter stages of this system.
First, severe-gale to storm-force winds over a short fetch in the 305-330 degree band is expected in an area 1500 to 1900 nm away on the W side of the occluded low near the Aleutians. Models show the system weakening steadily on Tuesday. This source will add high surf locally on Thursday, dropping on Friday.
Second, strong to marginal gales behind a eastward-pushing front on Monday into late Tuesday is expected to nose to within about 700 nm NNW of Oahu. This should add moderate, shorter-period swell of 11-14 seconds on Thursday into Friday from 310-345 degrees.
The combined effect should be a peak in local surf on Thursday from 280-330 degrees. With tidal phases near the neap, and only common winter high surf, coastal wave wash should not be out of the ordinary for the season at the high tide on Thursday.
Major revisions are given on the follow-up systems as compared to weather and wave model output last week, as pertains to local surf potential for this weekend. The latest models suggest the Aleutian low filling mid week with a zonal jet stream setting up at a normal winter latitude of around 40-45°N in the central north Pacific. Gale to severe gale winds associated with fast-moving surface low pressures are expected to track across the dateline and north of Hawaii along about 40°N with a 1-2 day spacing. The nose of each fetch of gales should reach to 30°N, with seas to 20-25 feet, giving reinforcement, short-lived, low-end, high surf episodes for Saturday and again a day or so later from 310-330 degrees.
Mid Monday on eastern shores has low surf under moderate trades. See the latest NWS state weather forecast discussion for details on local winds for the week. A near moderate, short-lived windswell from 30-60 degrees is expected on Thursday, with small windswell for Friday into the weekend.
Mid Monday on southern shores has tiny to small breakers. Surf is expected to pick up starting Tuesday, with various sources making southern shores above average this week.
Marginal gales associated with an extratropical cyclone south of French Polynesia about 4000 nm from Hawaii a week ago Sunday into Tuesday should make for small breakers locally starting Tuesday from 170-185 degrees with 11-14 second periods. This episode should hold into Thursday.
Tropical cyclone Oli tracked toward the SE to the W of Tahiti mid last week. The quadrant aimed at Hawaii had the lowest seas relative to the low pressure center. This source could add small breakers locally from 165-175 degrees on Wednesday into Friday.
Greater surf potential is expected from a storm-force extratropical cyclone that tracked NNE from Antarctica to the SE of New Zealand mid last week. The primary swath was aimed just east of Hawaii, but angular spreading could bring in moderate to marginally high breakers. Long period forerunners are expected from 180-190 degrees on Wednesday. The episode should peak on Thursday from 175-185 degrees, then slowly drop into the weekend. Select locations on southern shores should also received moderate or higher swell energy from 270-290 degrees on Wednesday into the weekend associated with the Tokyo source of this past weekend.
Into the long range, higher than seasonal average surf is expected on southern shores most of next week making for small to moderate breakers from 180-200 degrees, as extratropical cyclonic activity continues to the SE of New Zealand this week.
In the northern hemisphere, models keep a winter-type pattern with episodes reaching into the high category spaced about 3-4 days apart from NW to N. Hints of trades most days with low-end days allowing land and sea breezes and high-end days into the fresh category.
Long range forecasts have low confidence.
This collaborative forecast will resume on Wednesday, February 10.
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.
Additional Resources:
| Waimea Buoy | Kailua Buoy | Lanai Buoy | Kilo Nalu | Buoy 51001 | Buoy 51101 | Buoy 51000 | Buoy 51100 | Buoy 51002 | Buoy 51003 | Buoy 51004 |