BIG PICTURE: 11/20 Monday afternoon.
NPAC: Current Surf, above normal, peaked out at about 8-10 maybe a few 12′ for select outside spots earlier today. Laniakea reached 6-10′. With plenty of ‘inside’ spots were 4-6′ like Haleiwa. Winds were North so it was choppy, broken.
The main cause of all these North swells is a split Jetstream. There’s been a strong, persistent blocking ridge west of the dateline keeping most sources N of us to the Aleutians near the Gulf and Canada. But finally, after several weeks the Jet solidifies over the 7-day forecast off Japan to the dateline.
Our long lasting push of High Surf from the N starting Saturday nite. A large High far to our NNW with a Low in the Gulf create a fetch compressed between the 2 pressure systems. The long captured fetch journeyed straight South Thursday-Sunday just NNE of Hawaii! Aggravated seas built upon each other maximizing growth. Plus that flanking High helped to speed up these winds by ‘squeezing’ the Low’s pressure gradient. A serious upgrade occurred last Wednesday as the fetch nosed closer to Hawaii. Surf on this last one hit 12′ for top spots way outside line ups Sunday.
Next: The next Fat & juicy one comes on strong Wednesday night and peaks on Thanks Giving with plenty leftovers into the weekend due to the long fetch. It’s also from the North to NNW.
Swell Source see image Tuesday: The Gulf Low streams its fetch SSE across the East Aleutians from the Bering into Sunday-Monday 11/19-20 with up to 45kts and 25′ seas. By Monday the fetch nears 900-1200 miles long with some higher winds in the Low’s center. The track starts to move South garnering a captured fetch Tuesday-Wednesday as the nose of the fetch is just 600 miles NNE. Some energy is passing to our east. WW3 currently forecasts 9′ 15 sec NNW on buoy1 (270nw Hono)Wednesday night 11/22. Thursday, Thanksgiving’s peak is 10′ 15 sec NNW swell with surf refracting 10-18′ sets which is plenty bigger than Sunday’s episode for top 2nd Reefers and maybe some focal reefs like Laniakea 10-15′. Strong 15-25mph NE sideshore Winds will also be an issue for conditions. This North will go down to 8-12′ Friday the 24th and improving conditions; and with 6-10′ Saturday + Trades will be ENE 10-25mph. , the first day of the Vans World Cup which is likely to run.
Next: A strong but fast N tracking storm off Japan this Saturday zips up into the Sea of Okhotsk (Oh’gotsk) 🙂 off Russia next to the Bering Sea by Sunday eve; models suggest it’s the wrong track with all the energy passing to our north. Same as the downgrade low off Kamchatka. Models are fickle for the WPAC not able to compete with those Gulf systems.
Next: On Thanksgiving a new strong storm strengthens in the Bering sea off Alaska’s west coast with a SE track into the Gulf. Sea’s reach near 40′ but send most it’s swell to the NE. The Low stalls and broadens into Sat. the 25th with seas down to 32′. This long fetch is expected to send plenty with added energy from swell dispersion. WW3 suggests long 20 sec forerunners from the North (due to pockets of hurricane force winds) Sunday the 26th with surf going from 6′ in the AM to 10′ in the afternoon. Monday’s peak should hit 12′ easy and possilby near 15′ again with better conditions for the Vans World Cup.
LAST: A low pops Sunday the 26th off the Kurils Islands tracking East reaching the dateline Monday. We finally get a NW on the last week of Nov. At least that’s what the current chart claims. This is long range. But late Wednesday the 29th surf could be hitting 5′ at 15 sec. Thursday is the peak with maybe some 5-8′ sets at 13 sec.
SPAC: The Austral Spring has been pushing out above average surf from the Taz mostly.
Town: Surf keeps going at 2′ but every hour or so we see sets reach chest high from the SW at 13 sec; above the Nov. norm. Surf Sources have been the Taz. We should hold in that waist high for top spots top sets with stiff North winds. Better for Tuesday-Wednesday but it will be small at max 2′.
Long range: A fast east tracking 45-55kt Low far SE of NZL last Friday-Sunday pushing up some small 1-2.5′ SSW surf filling this Saturday-peaaking Sunday-fading Monday….
Windward: N to NW winds are due to a Low North dropping south; the cold front brought cold North to NNW winds Sunday-Monday. Trade swell will be trashed at normal sizes averaging 3′. Our wind waves will keep getting overrun by sequential sizable advisory level 5-8′ NNE swells and there’s no end in sight through next weekend. A strong NE wind swell picks up to 3-5′ Friday due to a buildingHigh-pressuree North of us. But again the BIG North will overrun it like a freight train. Things start to subside next week.
Tropics (West & East) was active that affect us this week.
For more on the Westpac Typhoons GO HERE
Note: the spectral density graph in the SNN Buoy Page (link below) shows slivers of forerunners that initial text readings do not ‘show’ till later on written buoy updates. Also, note the vertical graph is not ‘wave height’ rather its a measure of wave energy in hertz (frequency or cylces/sec) for the whole ‘band’ (the distribution of power/period in the total wave energy field/spectrum). For SNN’s Buoys ‘per shore’ arrangement pls GO HERE
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.
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 to 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 full ‘face’ surf height, or ‘trough to the crest’ of the wave.
Advisory and Warning Criteria Shoreline or Location
North-Facing Shores 15 Feet and 25 Feet
West-Facing Shores – Remaining Islands 12 Feet and 20 Feet
West-Facing Shores – Big Island 8 Feet and 12 Feet
South-Facing Shores 8 Feet and 15 Feet
East-Facing Shores 8 Feet and 15 Feet
‘Travel Time’ Buoy 51101 to Waimea Buoy. Distance: 269 nautical miles (~310 miles). Angle: 307 deg