Oahu Surf Conditions
Surf along north facing shores will be 3 to 5 feet today, lowering to 1 to 3 feet Friday.
Surf along east facing shores will be 2 to 4 feet through Friday.
Surf along south facing shores will be 2 to 4 feet today, rising to 3 to 5 feet Friday.
Surf along west facing shores will be 2 to 3 feet through Friday.
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, at the locations of the largest breakers. 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.
The SRFHFO product will change format and be expanded to more islands on or about September 10, 2020. More information at: https://www.weather.gov/hfo/statesurf2020 .
|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 in 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)|
DISCUSSION: SUMMARY.... Shorter-period NNW into weekend with new long period NW to NNW on Sunday.
DETAILED:. Mid Wednesday on northern shores has choppy breakers from 320-340 degrees below the October average. Surf is expected to rise on Thursday.
See the latest NWS State Forecast Discussion for trends in local winds and skies. Wind estimates in table above are open for updates given the unsettled weather pattern in the vicinity into the weekend.
A surface low pressure formed to the immediate NNW of Hawaii 10/26 and has remained nearly stationary into 10/28 near 35N, 160W. Models show it shifting slowly SE into Friday then lifting out to the NE Saturday.
ASCAT satellite starting 10/27-28 showed a long fetch of strong to near gale breezes on the W to N side of the surface low pressure area. The seas are aimed highest at targets west of Hawaii, but close enough for angular spreading to deliver significant waves locally. As of midday 10/28, the NOAA NW Hawaii buoys do not show any clear indication of the new event.
Short- to moderate-period surf is expected to build locally Thursday from 330-360 degrees with heights climbing to near the October average. This event should peak on Friday above average from the same direction, then slowly drop into Sunday. Proximity should equate with less organized breakers given the active energy expected in the 6-10s band along with the dominant 10-12 second energy, all from a similar direction.
A storm-force low pressure system is racing NE in the NW Pacific west of the Date Line near 40N, 170E 10/28. Models show the system dropping to 976 mb on Thursday 11/29 just east of the Date Line, then changing course more to the SE Friday into Saturday.
The early phase while west of the Date Line has limited feature duration and length due to the fast track of the center. Long-period swell from 305-320 degrees could pick up locally near sundown Saturday.
Once east of the Date Line, models suggest the strongest winds aiming well NE of Hawaii, so this NW to NNW event is not expected to be as large locally as last Sunday 10/25. Long-period swell from 315-335 degrees should rise on Sunday to levels above the fall season average by the afternoon. Wave energy should remain above average Monday with a downward trend.
The jog to the SE of the low pressure pattern Friday into Saturday is expected to set up a long fetch of gales over the 325-345 degree band nosing to within 1200 nm of Hawaii. This energy should be on the rise locally Monday PM, keeping above average surf into Tuesday 11/3.
Mid Wednesday on eastern shores has breakers from 45-70 degrees under the east side average. Heights are predicted to remain below average on Thursday.
Strong to near gale breezes beyond 1000 nm to the ENE to NE of Hawaii 10/22-24 sent remote wind swell that peaked locally 10/27 from 40-70 degrees. This event is waning 10/28. Models suggest that a weaker flair-up of remote winds over the same fetch 10/25-27 could keep low, remote wind swell locally 10/29-31.
Mid Wednesday on southern shores has breakers near seasonal background levels from 140-220 degrees. Similar surf is predicted for Thursday.
A series of gales hugging the Antarctic ice sheet S to SE of New Zealand 10/18-23 will most likely be the dominant source of small, long-period background surf through the weekend from 180-200 degrees.
Into the long range, a late-season, above average S swell is estimated for mid next week. A long wave trough at jet stream level has set up south of French Polynesia 10/27-28. At the surface, a broad area of severe gales to storm-force winds are aiming just SE of Hawaii while a more direct aim of strong breezes to gales aims directly at Hawaii 10/27-28. The fetch is wide and long with seas within 20-30 feet. Models show the pattern hovering near the eastern edge of the Hawaii swell window into 10/30. That means potential for a long-lived event.
Onset stage for long-period swell is due Tuesday PM 11/3 with the event filled in by Wednesday PM 11/4 above the summer average from 170-190 degrees. It should peak 11/5 then slowly drop into the weekend of 11/7 from the same direction.
East side is modelled to trend up 11/3-5.
For north shores, above average NNW to N surf is predicted for 11/3 aforementioned. Models show another broad area of gales moving east along 50N in the NW Pacific 10/31 reaching just east of the Date Line 11/2. This suggests an overlapping, new above average event locally from NW to NNW by 11/4 and holding into 11/6.
Long range forecasts are subject to low confidence.
The next Collaborative Forecast will be updated Friday, October 30.
This forecast was produced through the collaborative efforts of NWS and NCEI. Please send suggestions to email@example.com or call the Warning Coordination Meteorologist at 808-973-5275.
ADDITIONAL RESOURCES: See https://www.weather.gov/hfo/marine