SURF ZONE FORECAST
NATIONAL WEATHER SERVICE HONOLULU HI
353 PM HST FRI JUL 22 2016
353 PM HST FRI JUL 22 2016
HIGH SURF ADVISORY IN EFFECT FOR EAST FACING SHORES
Surf along north facing shores will be 2 to 4 feet through Saturday.
Surf along west facing shores will be 2 to 4 feet through Saturday.
Surf along east facing shores will be 8 to 12 feet through Saturday with occasional higher sets.
Surf along south facing shores will be 2 to 4 feet through Saturday.
Outlook through Friday July 29: the east swell from tropical storm Darby will continue to bring high end advisory level surf to east facing shores. Surf heights could possibly boost higher to warning levels depending on the eventual path and resulting windwaves of Darby. This would likely occur beginning Saturday night or Sunday, but forecast confidence is low given the small fetch. Either way, conditions will be very rough and choppy even if heights do not meet warning criteria. Surf heights along east shores will drop drastically after Darby moves west of Oahu. The north shores are also expected to experience a bump in surf, however a great deal of uncertainty remains with exact direction and heights. The event is forecast to bring rough conditions with a northerly component ranging from northwest to northeast Sunday. Surf is expected to drop drastically Monday. A background south southwest swell will continue through the weekend into next week.
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
120 PM HST FRI JUL 22 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: Rough surf from Darby over the weekend.
Detailed: Mid Friday on eastern shores has rough, well above average breakers from 50-90 degrees. Heights should be similar on Saturday.
See the latest NWS state forecast discussion for an explanation of local weather and winds and the Central Pacific Hurricane Center for status and forecasts of tropical storm Darby. The waves and winds in the table above for Saturday to Monday are subject to change based on the most up-to-date estimates regarding Darby.
Tropical low pressures combined with strong high pressure filling a vast area over the central north Pacific has set up a large fetch of fresh to strong breezes E to NE of Hawaii, with pockets to gales closest to the tropical systems. Proximity of Darby to Hawaii on 7/22 is increasing local seas and surf.
Pacioos/cdip nearshore buoy off Hilo Friday morning 7/22 shows a sharp jump in the 10-14 second wave energy from 80-90 degrees. These swell trains will be moving westward, though for Oahu, shadowing by more eastward islands decreases some of the longer period swell potential.
The strong trades over Oahu and immediately to the E to NE 7/21-22 have increased wave heights and periods on 7/22 within 50-90 degrees. Rough conditions are expected to continue from this directional band through Saturday with heights well above average. Based on the 7/22 morning forecast of Darby, wave energy from 50-90 degrees should trend down Sunday to levels near average by Monday as the Darby influence gains more northerly wave component.
High uncertainty on the amount of wave production within the quadrant from 315 to 45 degrees.or NW to NE, for 7/24-25. Rough conditions of northerly component surf is expected on Sunday. It should be of short-period nature and be short-lived, dropping fast on Monday.
Some low surf from tropical system Estelle, well ENE of Hawaii 7/19-22. Could keep surf from 80-90 degrees near average Monday into Tuesday. More typical summer trade windswell is expected by Wednesday.
Mid Friday on northern shores has breakers above the summer average for select NE exposures. Similar conditions should hold into Saturday, with choppy surf for Sunday from within 315-45 degrees. There is a chance for a short-lived spell of smooth ocean surface conditions early Monday assuming Darby exits the region and the s-component winds set in.
Mid Friday on southern shores has breakers near the summer average from 200-220 degrees. Heights are expected to drop from this direction on Saturday. Easterly exposures for Friday into Saturday should have surf from sources described above.
A storm-force low pressure in the Tasman sea 7/12-14 generated the surf arriving locally 7/22. The pacioos/cdip buoy off Lanai showed the peak of the swell 7/21. Heights should slowly decline over the weekend.
Low pressure over and east of New Zealand 7/15-18 placed a narrow fetch hugging the east coast of New Zealand and a wider fetch to the N to NE of New Zealand of mostly marginal gales. The pacioos/cdip american samoa buoy has been showing steady shorter period swell of 11-15 seconds from this source 7/20-22 with heights within 4 to 5 feet. After the 2100 nm travel to Oahu, swell near to a notch below the summer average is likely from 190-210 degrees Sunday to Monday.
A stronger gale NE of New Zealand 7/19-20 could give a pinch more size for Tuesday from 185-200 degrees. The system moved fast eastward as it weakened. The event should be short-lived locally at most to the summer average.
Into the long range, another storm-force system tracked east over the southern Tasman sea 7/19, nosing east of the New Zealand shadow as it weakens 7/20. A front pushed NE followed by gales pushing to near the subtropics 7/21. The system moved east of the Hawaii swell window 7/22. This source should tilt surf just above average for 7/28-29 from 180-200 degrees.
Tropical system georgette in the eastern Pacific will be monitored for surf potential locally. Otherwise, a long fetch of fresh trades is modelled over a large area E to NE of Hawaii 7/27-29 that should trend up the windswell from within 40-90 degrees.
Long range forecasts are subject to major revisions.
This collaborative forecast will resume on Monday, July 25.
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|