SURF ZONE FORECAST
NATIONAL WEATHER SERVICE HONOLULU HI
420 PM HST FRI DEC 9 2016
420 PM HST FRI DEC 9 2016
Surf along north facing shores will be 3 to 5 feet tonight, building to 5 to 7 feet Saturday.
Surf along west facing shores will be 1 to 3 feet through Saturday.
Surf along east facing shores will be 2 to 4 feet through Saturday.
Surf along south facing shores will be 1 to 3 feet through Saturday.
Outlook through Friday December 16: surf is expected to remain below advisory levels on all shores. A small north northwest swell will linger through the weekend followed by a moderate longer period northwest swell Monday into Tuesday. A moderate north northeast swell is possible by midweek.
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
255 PM HST THU DEC 8 2016
THIS COLLABORATIVE FORECAST WILL BE UPDATED MONDAY THROUGH FRIDAY AT
300 PM WHEN PAT CALDWELL IS AVAILABLE/
|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.
Discussion: summary: Remote and nearby sources for NW to N exposures.
Detailed: Mid Thursday on northwest to northern exposures has a mix of declining swell episodes from 300-320 degrees and 010-030 degrees, respectively. Low odds for a new NNW event on Friday.
The Thursday 12/8 WNW surf was generated west of the dateline last weekend. It should slowly fade out Friday. The 12/8 NNE event had a source between Hawaii and California 12/4-7. This event should also trend down 12/9 and fade 12/10.
A nearby low pressure has formed about 600 nm NNW to N of Hawaii 12/8. 11 am HST 12/8 ascat-b satellite showed a compact area of gales aimed at targets west of Hawaii. Given a similar pattern last week that manifested into higher than expected surf locally Sunday 12/4, this feature deserves attention. Models show the low remaining nearly in place with a trend for the strongest winds to aim more westward, that is, less at Hawaii.
The head of the fetch is about 500 nm away on 12/8, which should allow a rise locally mid to late Friday from 340-360 degrees from angular spreading. This makes for large error bars on the specific heights. Stay tuned to the latest forecast updates, which can be fine-tuned with the latest buoy data and surf observations.
The low pressure just north of Hawaii 12/8 is expected to be long-lived and slow in movement. It will likely keep NNW to N surf into Monday 12/12 at levels below the active season, September to may, average.
Models show this low pressure moving NE 12/11-13. A strong high pressure SE of the eastern Aleutians in combination with this low is predicted to make a wide fetch of marginal gales in an area between 800-1500 nm away starting late 12/11. This should trend the local surf up mid Tuesday 12/13 from 010-030 degrees. It should last into 12/16.
Further west, a storm-force low pressure system tracked NE along the kuril island archipelago to Kamchatka 12/6-7. The length of the fetch east of the NW Pacific basin edge was short. A low, long-period swell from 305-315 degrees is estimated for Sunday 12/11, making for small breakers.
A stronger low pressure in a position further east of the Kurils formed 12/7-8. It is gaining hurricane-force 12/8 as it tracks rapidly NE. It is expected to weaken as it crosses the Aleutians west of the dateline late 12/9. Long period swell are due locally Monday 12/12 from 305-315 degrees. It is expected to peak near the seasonal average late Monday then slowly trend down Tuesday 12/13.
Mid Thursday on eastern exposures has declining breakers from 60-100 degrees at levels below the trade windswell average. Heights should drop further on Friday.
A large area of weak winds E to NE of Hawaii over the 60-100 degree fetch should keep windswell at a minimum through the period.
Mid Thursday on southern shores has near flat to small breakers as typical for December. No surf beyond tiny to small is expected through the period.
Into the long range, a deep low pressure tracked east along 65°S from south of Tasmania to SE of New Zealand 12/4-6. Wave models only give 1 feet deep water swell at the equator for Sunday, so likely it would not climb out of the tiny bracket locally next Tuesday 12/13, though could be a bit more than 12/9-12. This very low, long-period swell from 185-220 degrees could last a few days.
In the northern hemisphere, a long, wide fetch stretching from the Kuril Islands eastward to near the dateline 12/11-12 should trend the surf up near to above average within 12/15-16. This event could combine with a new nearby low pressure. With the mix in model expectations, it is too early to speculate on the cumulative results locally. There is more confidence in the remote source than the nearby one.
Windswell within S to W from the nearby low pressure 12/15-16 could accompany the remote, long-period WNW to NW swell.
Long range forecasts are subject to high uncertainty.
This collaborative forecast will resume on Monday, December 12.
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
|Waimea Buoy||Kailua Buoy||Lanai Buoy||Barbers Point #2||Pauwela, Maui||Hilo Bay Buoy||Kaneohe Bay Buoy||Hanalei Kauai Buoy||Kilo Nalu||Buoy 51001||Buoy 51101||Buoy 51000||Buoy 51100||Buoy 51002||Buoy 51003||Buoy 51004|