SURF ZONE FORECAST
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST WED JAN 28 2015
400 AM HST WED JAN 28 2015
HIGH SURF ADVISORY FOR NORTH AND WEST SHORES
Surf along north facing shores will be 12 to 18 feet through tonight, lowering to 10 to 14 feet on Thursday.
Surf along west facing shores will be 8 to 14 feet through tonight, lowering to 6 to 10 feet Thursday.
Surf along east facing shores will be 1 to 3 feet through Thursday.
Surf along south facing shores will be 2 feet or less through Thursday.
Outlook through Tuesday February 3: the current advisory-level northwest swell will peak tonight and gradually lower on Thursday. Reinforcing swells from the northwest will arrive Friday and Saturday, with the Saturday swell likely resulting in advisory-level surf along north facing shores. This swell will gradually diminish through Tuesday.
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 JAN 26 2015
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 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)|
SURF HEIGHTS WILL VARY BETWEEN DIFFERENT BEACHES AND AT THE SAME
BEACH AT DIFFERENT BREAK AREAS.
Summary: long-lived event within WNW to NNW this week.
Detailed: mid Monday on northern shores has breakers near the October to April seasonal average from 290-315 degrees. This event should fade to small levels Tuesday morning as a new event slowly builds.
A low pressure system dropped below 970 mb last Friday 1/23 just east of Hokkaido, Japan. The system slowly weakened as it tracked east along 45°N. Hurricane-force winds declined to severe gales as the head of the fetch over the 300-310 degree band approached 170°E late last Saturday. The jason altimeter estimated seas over 25 feet on Sunday in an area about 1800 nm away.
Surf from this remote source is predicted to arrive locally on Tuesday morning with heights staying below average until the afternoon with 17-21 second intervals from 300-310 degrees. Energy from this WNW direction should peak on Wednesday, drop below average by Thursday and fall to small levels on Friday. Additional NW energy is due Wednesday.
The central north Pacific low pressure system continued to slowly weaken as it approached the dateline late Sunday 1/25, crossing east of the dateline on Monday 1/26. Winds settled to mostly gales over the 305-320 degree band, nosing to near 1200 nm away from Hawaii Monday morning. Proximity should give this source the dominant surf size by mid Wednesday 1/28. This NW energy should peak late Wednesday above the seasonal average, then slowly drop Thursday at levels above to near the average, and fall below average on Friday. New NNW energy is due on Friday.
The low pressure east of the dateline on Monday 1/26 is expected to move to a position well north of Hawaii on Tuesday and hover nearly stationary into the weekend. This will make for a long-lived spell of NNW surf.
Models show near gales over the 320-340 degree band about 1000 nm away by early Wednesday. This shorter-period NNW wave energy should over lap the dropping WNW and NW swell trains of similar wave periods by 1/30, making for a wide spread in wave direction Friday from within 300-340 degrees with 10-13 second wave periods. Surf on Friday should be a notch below the seasonal average.
An enhanced area of gales is expected to form on the NW quadrant of the low pressure north of Hawaii late Tuesday. A captured fetch over the 320-340 degree band is modelled to set up as an embedded low pressure trough digs SSE 1/28-29, reaching about 1000 nm away by Thursday. This should increase the swell height and dominant period on Saturday, with surf climbing above average again.
Mid Monday on eastern shores has surf below the trade windswell average from 30-60 degrees. Similar size is expected on Tuesday.
A 1021 high pressure cell NNE of Hawaii near 30°N on 1/26 is moving east and weakening. The fresh trades of 1/26 near the Hawaiian islands are modelled to weaken to moderate levels on Tuesday as the direction veers to easterlies. As the large scale low pressure north of the islands shifts eastward 1/27-28, the local winds are expected to weaken further, leading to declining, tiny to small easterly windswell on Wednesday.
See the latest NWS state forecast discussion regarding the mostly gentle winds of varying directions Thursday to Saturday. Windswell is expected to stay near nil during this period.
No surf beyond tiny is expected from the southern hemisphere this period. Westerly swell for exposures to 270-295 degrees should remain nil to tiny through the period.
Into the long range, the long-lived, nearly stationary low pressure area north of Hawaii is expected to slowly weaken 1/31-2/1 as it drifts NE. Surf above the seasonal average 1/31 should slowly decline 2/1-2 from within 325-360 degrees. Windswell is predicted to remain low 2/1-2.
Long range forecasts are subject to major revisions.
This collaborative forecast will resume on Wednesday, January 28.
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.
|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|