Surf Report for Hawaii
Surf along south facing shores will be 2 to 4 feet through Thursday.
Surf along north facing shores will be 2 feet or less through Thursday.
Surf along east facing shores will be 2 to 4 feet through Thursday.
Surf along west facing shores will be 1 to 3 feet through Thursday.
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.
|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.... Low-end summer surf.
DETAILED:. Mid Monday on northern shores has decreasing, short-period breakers from 10-20 degrees. Heights are expected to favor tiny levels by Tuesday.
The weekend NNE event peaked locally Sunday 8/2. It was generated by a nearly stationary, compact, near-gale low pressure in the Gulf of Alaska 7/28-29. This event should fade on Tuesday.
A broad area of low pressure in the Bering Sea tracked east 8/1-3. It placed strong to near-gale breezes south of the Aleutians with most direct aim at targets NE of Hawaii. The fetch was closest to Hawaii, about 1800 nm away, early 8/3. Seas barely surpassed 12 feet. With the low magnitude and long travel distance, only a tiny to small event is predicted locally. It should pick up Friday 8/7 from 330 degrees and drop on Saturday from 345 degrees.
Otherwise select exposures to trade wind swell should trend up for the latter half of the week as described below.
Mid Monday on eastern shores has breakers at an east side minimum. Heights should remain low on Tuesday.
Waves are at a minimum 8/3 because the center of high pressure was more NW of Hawaii over the weekend and an upper level trough aided to weaken the upstream trades to mostly gentle speeds E to NE of Hawaii out 800 nm 7/31-8/2.
The high pressure system has shifted east to a position north of Hawaii 8/3. ASCAT satellite late 8/2-3 shows a large area of fresh trades has formed within 135-145W south of 30N with moderate to fresh pockets closer to Hawaii. The fresher breezes are modelled to shift westward making for a long fetch. This should trend up the dominant wave period in Hawaii midweek, and in turn, the local surf. Heights should climb to near average from 60-90 degrees by 8/5 PM and hold about the same into Friday. Hints of surf a notch higher for the weekend.
Mid Monday on southern shores has breakers at a south side, summer minimum. It should be similar on Tuesday.
Southern hemisphere and equatorial trades within fresh to strong levels covered a large area within 120-150W over 20S to 7N last week. Southern Hawaii NOAA buoys 51002 and 51004 show this source from 120-160 degrees as the dominant swell that is just above the threshold in wave period to distinguish it from wind waves. This source should be long-lived, making small breakers for SE exposures this week. Models hint at a minor decrease 8/7-8.
An east-moving gale low S of New Zealand 7/27 began an equatorward track near 160W 7/28. The ocean surface winds weakened to mostly near gales as the fetch stretched toward the subtropics. ASCAT 7/29 AM showed the head of the fetch to 35S. The fetch towards Hawaii mostly ended 7/30 as the seas were aimed toward the NW well SW of Hawaii.
The initial stage could bring low, inconsistent, long-period surf locally 8/4 from 190-200 degrees. Better odds for the moderate wave period stage with surf building from 170-190 degrees to near average 8/5. It should peak Wednesday night and slowly fade to background by 8/7.
Into the long range, the south side should be at a minimum 8/9-14. The north side could get another tiny NNW event 8/10 from another system 8/4-6 centered in the Bering Sea with fetch hugging south of the Aleutians.
East side likely to top the heights 8/9-12 with average or a notch higher trade wind swell from 60-90 degrees.
Long range forecasts are subject to major revisions.
The next Collaborative Forecast will be updated Wednesday, August 5.
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 https://www.weather.gov/hfo/marine