SURF ZONE FORECAST
NATIONAL WEATHER SERVICE HONOLULU HI
640 AM HST SUN FEB 14 2016
640 AM HST SUN FEB 14 2016
HIGH SURF ADVISORY FOR NORTH AND WEST FACING SHORES
STARTING AT 9 AM HST TODAY
Surf along north facing shores will be 4 to 8 feet early this morning, rising to 10 to 15 feet by midday, and 14 to 18 feet this afternoon. Surf will remain near these heights tonight, and slowly diminish to heights of 12 to 16 feet on Monday.
Surf along west facing shores will be 2 to 4 feet this morning, rising to 8 to 12 feet by midday, and remaining near these heights through Monday.
Surf along east facing shores will be 3 to 5 feet through tonight, rising to 4 to 6 feet Monday.
Surf along south facing shores will be 2 feet or less through Monday.
Outlook through Sunday February 21: a new west-northwest will peak tonight, then slowly lower through Thursday. Strong trade winds will produce rough surf along east facing shores by mid-week, and this surf may reach advisory levels. A moderate northwest swell is expected Friday and a large northwest swell is possible next Sunday.
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
250 PM HST FRI FEB 12 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: Westerly and easterly component waves for the weekend.
Detailed: Mid Friday on northern shores has breakers from 320-350 degrees above the October to April seasonal average. Heights are expected to drop below average on Saturday.
The large Aleutian low pressure that generated the winter-caliber surf 2/10-11 had the tail of the fetch of subsiding gales over the 320-330 degree band about 1600 nm away on 2/9-10. The NOAA NW Hawaii buoys 2/12 show a steady drop in wave height and dominant wave period. The Wave Watch III model has compared well with data for the Waimea buoy output point 2/11-12. Given the good comparison, the ww3 estimate appears to be the best guidance for 2/13. This event should slowly decline Saturday into Sunday as a new event builds.
Most of the low pressures in the north Pacific over the past 6 weeks have occluded near to east of the dateline. The occlusion point is when the fast-tracking low pressure cell abruptly slows in track, the size of the low pressure area widens, and the surface winds become the strongest. With the occlusion point close to Hawaii in recent weeks, surf has been well above average.
A new low pressure occluded much further west on 2/10 east of the Kuril Islands. The system slowly tracked east from near 165°W along 42°N, reaching the dateline 2/12. Winds were mostly gales with pockets to severe gales, weaker than most winter systems. It did have an extra wide fetch and long over the 290-310 degree band nosing to near 1200 nm away on the dateline 2/12. Seas are mostly near 25 feet on 2/12.
Models show the low center rapidly filling and moving N 2/12-13 as the surface winds steadily drop sub-gale by 2/13. Shadowing by Kauai on Oahu increases error bars on local surf size estimates for this westerly-component event.
The event is due to build in the wee hours Sunday morning from 290-310 degree, with heights climbing above average. The event should peak late Sunday. It should remain above average on Monday with a steadily decline Tuesday into Wednesday from 290-325 degrees.
Models show a gale low forming near the dateline at 40°N on Sunday and racing east past the longitude of Hawaii by late Monday. The head of the fetch is estimated about 900 nm away mid Monday. Wave watch iii brings in this new event on Wednesday at surf levels near the seasonal average from 320-340 degrees. It should be short-lived.
Mid Friday on eastern shores has choppy, small breaker from 70-100 degrees. Heights should pick up on Saturday.
See the latest NWS state forecast discussion for details on the local winds and weather.
Models are showing an area of fresh to strong breezes north of the eastern-most islands to near Oahu late Friday into Saturday 2/12-13. This should bring up breakers from windswell 2/13 from 80-100 degrees to near the trade windswell average. The breaker heights should be about the same Sunday due to the source east of Oahu even though local winds are predicted to subside.
Models show a new trade wind event filling in on Monday to fresh levels from 50-70 degrees. Models have been consistent in showing winds increasing to strong levels from 30-60 degrees by Tuesday. This should make for rough breakers at levels above the trade windswell average building 2/16. A slow decline in winds and waves is predicted for Wednesday from 40-70 degrees.
No surf beyond tiny to small is expected from the southern hemisphere this period and 2/18-19.
Into the long range for the north shores, below average NW to N surf is modelled for 2/18-20 as the easterly windswell subsides. Models suggest a return to winter caliber low pressures near to east of the dateline starting 2/19 that should coincide with a trend up in surf from WNW to NNW around 2/21.
Long range forecasts are subject to major revisions.
This collaborative forecast will resume on Tuesday, February 16.
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|