Oahu

Maui

Kauai

Big Island

Weather

Surf Advisory and Warning Criteria
Location/shoreline Advisory Warning
North-Facing Shores- 15 Feet faces (8' Local) 25 Feet faces (15' local)
West-Facing Shores - 12 Feet (7' local) 20 Feet (12' local)
West-Facing- Big Is.- 8 Feet (4'+ local) 12 Feet (7' local)
South-Facing Shores- 8 Feet (4'+ local) 15 Feet (8' local)
East-Facing Shores- 8 Feet (4'+ local) 15 Feet (8' local)

Big Picture

BIG PICTURE: Friday 9/29/17
NPAC: The Jet is fairly low with up to 180kts but flowing ENE from Japan not steering storms closer to us.
There’s a big split just to our NW some dips/troughs setting up for some circulation at the surface a couple times this 7-day trend. But, extreme dips and splits can be too steep hindering gradual connections between the upper flow and surface.
From our NE to the west coast it’s a mostly zonal flow with only 140kts. More energy is needed in these upper level wind regions 30,000 ft up in the EPAC.
A large area of High pressure which has persisted for a majority of the East Pac where the Jet bumps up and over is finally giving way a little this coming week tho’ briefly.
By next week Monday the 2nd of Oct., the Jet has dissipated into summer like levels but thanks to some dipping we do get a gale spinner Oct 3rd (read below).
Luckily by Wednesday it’s reconsolidated from Japan with some 180kts and again a ENE tilt to our longitudes above the Aleutians.
There’s minor trough to our N and more ‘blue’ or high-pressure re-establishing in the EPAC.
A cut off low just to our NE by Friday, as of now, it may lead to some interesting winds, weather and some NNE sideband surf over the weekend of the 7th.
#1 Recently/currently:
We’ve had some fun NNW to NNE swell this week getting to just overhead at focal reefs. Friday it’s still 1-3’ top spots top sets but not as ‘put together’. It came from an east to ENE bound Low to our NNW starting last late Sunday as it ended in the Gulf. Fetches continued on it’s West flank into Wednesday. This is outta here by Sunday.
#2 Next: A much better NNW episode (1st one of Oct) is setting up for Monday2 Tuesday3 up to maybe 6’ or double overhead. The storm is 1200mi to our N-NNW by Saturday and it stalls (occludes: which is good as winds aren’t strong and this give winds more time). The Low weakens more and more Sunday-Monday as it’s fetch noses from 900 down to 300 miles.
Models have been so fickle on this oct 1st event but now it looks good to go. They started at 6’ then backed down 3’ then up to 5’ now back to 3’ surf maybe 4’ Sunday-Monday Oct 1st-2nd. Now, finally it’s likely to peak near double overhead for focal reefs with winds Variable.
#3 Last: Another compact low pops on the charts esp. by Monday Oct 2nd as it crosses the dateline intensifying with a nice ESE track. This is a partially captured fetch which means the fetch ‘follows’ the storm center/track, leading to increased surface wind support). It’s fading out by Wednesday to our North but not without sending down some more NNW veering N swell this Wednesday the 5th with up to 5’ surf at 12 sec. Trades are expected back by this time.
SPAC: The JETSTREAM fattens up on the first days of this 7-day model run. But the energy is still not optimally placed NE up the east coast of New Zealand. This reflects our transition into Fall and the Jet falls apart from Tuesday-Friday.
#1 Recent + Today: It’s been tiny but rideable from the generic SSE-SE ‘trade swell’ this week with averages of 2’ but with tons of waiting.
#2 Next: A 45-55kt Low built up to 30’ seas as it tracked zonally from under NZL early this work week. But this was pointing to the Americas. However, due to size and strength we may rely on some long period sideband surf from swell dispersion. So far however, WW3 predicts only 1.2’ deep water at 18-20sec initially around Wednesday the 3rd. Those long periods come from high winds and can sometimes refract/shoal swell 3-4 or even 5X’s the ‘swell or deep water’ height. If this pans out Wednesday then we could see one or two 3’ sets if lucky every hour for top spots.
#3 Next: This Big storm continues is east bound journey and by Wednesday the 27th more storm force pockets are seen. But again, their fetch is zonal to ENE and skewed toward South AMER and Baja and Cali.
Then by Thursday the fetch points & moves more NE and by Friday the damn thing is 1500 miles long but just East of the 150W longitude of French Polynesia. They’ll be pumping and so will all the aforementioned zones. Hawaii will beg for sideband swell of 3’ Sat/Sunday 7-8th. Periods will be 11 sec by this time. They’ll start at 16sec when the earlier stage of the storms winds were strong.
#4 Last: A powerful Low including a reinforcement Low on it’s heals gets up to 45’ seas projects for Oct 3rd SE of New Zealand. Again, the damn things move west to east and thus once more we must receive smaller sideband swell instead of 5’ SSW’s we’d have a NE track. At any rate, due to the sheer power WW3 does claim a full week of fun 3’ SSW surf Mon-Friday Oct 9th-13th. Better than July and August.
TRADE SWELL
Trades swell below average and will remain so at least into oct 5th. There’s a Low’s weak surface trough pushing our high east and weakening it and its ridge down near the Islands from the NW. Winds will be light enough for sea breezes thru Tuesday….so tiny clean wind swell. Good diving for Windward all weekend pending rain and cloud cover. Trade swell re-establishes from Wed or Thursday to near normal or up to 2 or 3’ with minor flux.


TROPICS: Nothing today nor for the weekend.

Get the latest on the tropics at www.hurricanes.gov
The Central Pacific Hurricane Center outlook for the 2017 Central Pacific Hurricane Season calls for 5 to 8 tropical cyclones to either develop or cross into the Central Pacific with a 40% chance for an above-normal season, a 40% chance for a normal season, and a 20% chance for a below-normal season. An average season has 4 to 5 tropical cyclones, which include tropical depressions, tropical storms, and hurricanes.
A tropical depression forms when a low-pressure area is accompanied by thunderstorms that produce a circular wind flow with maximum sustained winds below 39 mph. An upgrade to a tropical storm occurs when cyclonic circulation becomes more organized and maximum sustained winds gust between 39 mph and 73 mph. A tropical storm is then upgraded into Category 1 hurricane status as maximum sustained winds increase to between 74 mph and 95 mph. (The highest classification in the scale, Category 5, is reserved for storms with winds exceeding 156 mph).
Tropical cyclones go by many names around the world, and the terminology can get confusing. Once a tropical cyclone strengthens to the point where it has gale-force winds—39 mph or greater—it becomes a tropical storm. A storm that reaches tropical storm strength usually gets its own name to help us quickly identify it in forecasts and warnings. Once a tropical storm begins producing sustained winds of around 75 mph, we call the storm a typhoon in the western Pacific near Asia and a hurricane in the oceans on either side of North America. A “typhoon” and a “hurricane” are the same kind of storm, they just go by different names…it’s only a matter of geography.
NWS criteria for High Surf Advisories & Warnings.
In coordination with civil defense agencies & water safety organizations in Hawai`i, the NWS uses the criteria below for the issuance of High Surf Advisories & Warnings in coordination with civil defense agencies & water safety organizations in Hawai`i.
All surf height observations & forecasts are for the full face surf height, from the trough to the crest of the wave.
Advisory and Warning Criteria Location
Warning North-Facing Shores 15 Feet 25 Feet
West-Facing Shores - Remaining Islands 12 Feet 20 Feet
West-Facing Shores - Big Island 8 Feet 12 Feet
South-Facing Shores 8 Feet 15 Feet
East-Facing Shores 8 Feet 15 Feet
'Travel Time' Buoy 51101 to Waimea Buoy. Distance: 269 nautical miles (~310 miles). Angle: 307 deg
Wave Wave Wave Depth Wave Direction (deg)----------
Period Length Speed Shallow 295, 305, 315, 325, 335, 345, 355
(s) (ft) (nm/h) (ft) Travel Time (hours)----------
10sec. 512. 15. 256. 17.3, 17.7, 17.6, 16.9, 15.7, 14.0, 11.9
12sec. 737. 18. 369. 14.5, 14.8, 14.6, 14.0, 13.0, 11.6, 9.9
14sec. 1003. 21. 502. 12.4, 12.7, 12.5, 12.0, 11.2, 10.0, 8.5
16sec. 1310. 24. 655. 10.8, ,1 1.1, 11.0, 10.5, 9.8, 8.7, 7.4
18sec. 1658. 27. 829. 9.6, 9.8, 9.8, 9.4, 8.7, 7.8, 6.6
20sec. 2047. 30. 1024. 8.7 8.9 8.8 8.4 7.8 7.0 5.9
22sec. 2477. 33. 1239. 7.9 8.1 8.0 7.7 7.1 6.3 5.4
24sec. 2948. 36. 1474. 7.2 7.4 7.3 7.0 6.5 5.8 4.9

Tropical Storms - wind 39-73 mph (34-63 kt)
Category 1 - winds 74-95 mph (64-82 kt)
Category 2 -winds 96-110 mph (83-95 kt)
Category 3 -winds 111-130 mph (96-113 kt)
Category 4 - winds 131-155 mph (114-135 kt)
Category 5 -winds 156 mph and up (135+ kt)
Please visit the Central Pacific Hurricane Center website at www.weather.gov/cphc for the most recent bulletins.
ENSO is a single climate phenomenon, it has three states or phases. The two opposite phases, “El Niño” and “La Niña,” require certain changes in both the ocean and the atmosphere because ENSO is a coupled climate phenomenon. “Neutral” is in the middle of the continuum. The MJO (Madden-Julian Oscillation) is an eastward moving disturbance of clouds, rainfall, winds, and pressure that traverses the planet in the tropics and returns to its initial starting point in 30 to 60 days, on average, unlike ENSO which is stationary. In a nutshell, more active means more surf.
Kelvin wave (A Kelvin wave is a wave in the ocean or atmosphere that balances the Earth's Coriolis force against a topographic boundary such as a coastline, or a waveguide such as the equator. A feature of a Kelvin wave is that it is non-dispersive, i.e., the phase speed of the wave crests is equal to the group speed of the wave energy for all frequencies. This means that it retains its shape as it moves in the alongshore direction over time.)