Big Picture

SNN BIG PICTURE: Tuesday 5/15/18

NPAC:  It’s been good for May esp. mid-may. The Jet continued like a coiling snake, starting weak NE up off Japan-Kurils-Kamchatka then dropping SE toward Hawaii on our side of the dateline with 140kts. This sets up the weak surface Low for Friday-Saturdays NNW.

Winds really back down this week and the split moves far east with unconsolidated Jet stream winds weak up to 120mph. Not enough.

But winds consolidate off Japan up to 160kts this weekend. The trough moves east across the NPAC as the Jet weakens yet again. By next week of the 21st it’s further North, thinner and zonal but at least consolidated. Some soft Lows spawn to keep the NW events continue albeit tiny.

Jet-Theme: The higher the upper air currents (E.g. 180-200+), the higher the atmospheric energy and thus, the higher the potential for that energy to transfer to the ocean surface as storms.

Recent-Current: Small but very doable with up to head high or 3’ surf on the decline now. The NE trade bumpiness haven’t been optimal thanks to the side-shore nature of this angle. More East the better. In fact, SE are best for NW shores.

Next:  A distant weak eastbound Low centered near the Kuril Islands Friday-Sunday the 11th-13th is projected to send us some tiny 12 sec NW surf Thursday to about 2 not quite 3’. But Friday-Saturday the NW will veer NNW and peak at 2-3+’ or just overhead. This will be due to the rebuilding of the storm prior to our NNW Tuesday the 15th… the periods will only be 11sec due to the average gales. We’ll have moderate ENE Trades for decent conditions.

Next: Another small storm tracks East off the Kuril’s Monday-Tuesday the 14-15th. Waves up to 2’ from the NW might get here Sunday the 20th thru Monday. It’s pretty lame through the end of May.

Last: A better storm tracks mostly East off the same area Thursday-Sat. the 17-19th when the Low ends up on our side of the dateline way up by the Aleutians. WW3 is hinting at 14 sec forerunners late Tuesday the 22nd. The surf should peak at 2-4’ Wednesday. After this we go quite for a few days. Meaning it could go flat- inches the last week of May.


The Jet has been good recently and has lead to a couple solidly fun SSW episodes, the first of which is building Tuesday. Though the Jet stream has turned off and on…this coming 7 days the North branch looks strongest which is not good for Hawaii. The saving grace is a solid flow up the Taz Tuesday the 22nd.

Recent/current:  It’s been small but a long period new 17 sec SSW is rising to just over 3’ today all day. Wed AM as it fades but with more consistency. The extreme New Moon’ tides are influencing the size and consistency. This one’s Thanks to a powerful Eastbound Low which moved out from the Taz and east of New Z Monday the 9th. Seas up to huge 50’ seas!

It weakened esp. by last Wednesday with 30-45’ seas. A classic moderate summery event. If this storm had tracked NE instead of the east we’d have seen at least 4-6’.

Next:  The next ENE moving Low nails 30’ seas far SE of New Z Friday the 11th. Then, Saturday the 12th the next storm spins ENE to East with stronger winds and begins weakening into Sunday. This storm is big and strong enough for some long period 3’ SSW sets later Saturday the 19th into Sunday, the peak could be 2-4’ as the swell completely fills. Even Monday the 21st could still have a few.

The system tracks far East and rebuilds with 45’ seas S to SSE of Tahiti Tuesday the 15th but it points mostly out of our swell window. Sideband SSE surf could reach us but let’s wait a few days before claiming.

Next 2: This Wed-Thursday models show another Taz storm track east with some 45kts weakening right at it ventures out of New Z Friday the 18th. Another Taz Low with higher winds moves up the Taz from Friday-Sunday. Look for some 2-3’ sets from both storms starting Wed. the 23rd into Friday. The next SW hits buoys late Thursday peaking Friday with deep water of 2’ at 16s. So, easily Head High sets.

Last: A really big strong Low moves up the Taz Monday 21-23. If all goes well with this long- range model fantasy we’ll see some near rare near 4’ sets from the SW around Wednesday the 30th.

Windward Shores:

Recent-current: 8 second ENE trade swells at Makapu’u hang out thru the next 7 days even tho’ winds weaken a couple days.

Tropics: The recent Low has dissipated off Baja.



NWS criteria for High Surf Advisories (first number) & Warnings (second number).

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

Links: Get the latest Central Pac Hawaii go HERE

Terms:  split Jetstream

blocking ridge

short-wave tough

Notes: Spectral density graph in the SNN Buoy Page GO HERE  shows slivers of forerunners that initial text readings of new swells which often do not ‘show’ till later on written/text buoy updates. Also, note the vertical graph is not ‘wave height’ rather its a measure of wave energy in hertz (frequency or cycles/sec) for the whole ‘band’ (the distribution of power/period in the total wave energy field/spectrum). For the SNN Buoys ‘per shore’ arrangement  GO HERE

Links: Get the latest on the Eastern North Pac GO HERE For more on the West Pac Typhoons GO HERE


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