Big Picture

SNN BIG PICTURE: Wednesday 9/18/19 




The Jet has really improved toward Fall (1st day 9/22) esp. this upcoming week. Winds are stronger (up to 180kt zones) and it’s dropped in Lat. esp. by Friday to around 40-50 degrees with a longer more consolidated flow extending from Japan to beyond our 160 longitudes. The Jet sweeps up into the Gulf and down the Pac NW coast this weekend and by Monday the 23rd the Jet is split to our NW on our side of the 180 dateline…this ‘break’ increases as it migrates eastward thru the end of this 7 day. The upshot is this energy in the upper region is generating/transferring to the ocean surface and generating more surf in our area from the NW.

Jetstream: Large scale ‘river of wind’ about 30-35,000ft in our upper atmosphere flowing west to east circling earth in both Hemispheres. It has major impacts on climate, weather, and airmass (Lows and Highs) which help form and steer storms that bring our waves.

Recent-Current: We’ve had minor NE wrap last week… plus some traces of NW to NNW (from distant sources) up to 2’-2.5’ over the past 10 days or so …keeping it rideable. Same for today with 2’ sets at 13 sec NW from a Low off near Kamchatka end of last work week.

Next: A better Low with a better track starting off Japan then moving North off the same area as the prior low Tuesday-Wednesday…but this Low then tracks toward us ESE and reaches the dateline Thursday as is dissipates. Watch for some 15 sec forerunners Sunday with swells up to 2’ leading to 3’ surf. It wont last long as Monday will see a large drop to 12 sec and likely just 2.5’ surf.

Next: A marginal Gale Low we see next is moving east this weekend off the Kuril Is…. it’s weak with only 18’ seas. Look for short 11 sec period NW surf to hit 2’ maybe 2.5 Wed. nite into Thursday the 26th for a day before fading Friday as it veers NNW to N.

Last but not least: This Monday-Wed a zonal then NE tracking average Low off the Kurils reaches 20-25’ at first… but the storm rapidly intensifies off Kamchatka Wed. the 25th become rather ‘wintery’… Seas get to a whopping 45’ as the system is tracking East along the West Aleutians into Thursday… here it begins to weaken. Results: Sunday the 29th WW3 seas a honest ground swell of 4’ at 16 sec which could spell up to 5’ maybe 6’ at top ‘jacking’ reefs Sunset due to the periods. This is a long way off. So far, this early season WW3 has been running hot with the ball, then dropping it. So, this is just a heads up.


The Jet’s zonal Northern Branch (170kts) is zonal over the Taz and nosing toward the dateline. The Southern branch is looking pretty good with a meridional flow (swerving NNE) off 140 kts right up the east coast of NZL. The Jet returns to Zonal for the main Southern branch into this weekend. The long range (out a week) doesn’t look great. Still, it looks as though we’ll have SSW’s all the way through the end of Sept.

Recent-Current: Surf’s been fun with plenty head high sets from the Taz/SW and SSW (east coast of NZL) along with some SSE. Some reefs even got 1’ overhead but none of this was regular and all over. The SW was from 45-55kts under the Taz last Tuesday-Wednesday.

Next: A decent low SE of NZL Friday the 13th grew to be ‘wintery’ but is tracked east. Still, we’ll see some 16+ sec head high SSW sets (thanks to angular spreading) Friday peaking Saturday from a more South direction… maybe just overhead… and NE offshore Trades.

Next: A Low tracks East under the Taz and gets out to the SE of NZL this past weekend the 14-15th into Tuesday the 17th. So, the first batch of surf will be a 2’ SW then 2.5’ SSW surf. Expect overlapping events Monday the 23rd into Wednesday when the bigger SSW fills in. Let’s go with 2’ Monday and 3’ Wednesday the 25th.

Last: A much larger Low (Tuesday-Wed the 18th) is passing far to the SE of NZL with 30+’ seas and tho’ it stays way down near the Ice shelf, the fetch on it’s West flank seem to have WW3 fantasizing a really fun SSW filling Thursday on top of the other swells. A chance for some 2-4’ SSW builds Thursday (esp. later) and holds solid 2-4’+ into Saturday.

Windward: Makapu’u along with most our favorite Trade Wind swell reefs have been small at 1-2.5’ average. We might see an uptick to 3’ this weekend with local and upstream trades.

The EAST Pac Tropic: minor 12 sec East swell from ‘Kiko’ -the now Trop Storm- may send some 2’ surf Thursday-Friday. It’s less than the local Trade swell but it’ll be ‘felt’.

The West Pac Tropics : No surf from this region over the coming 10 days.

Long-range views are seldom 20/20. Prep for some adjustments.


On SNN: spectral graphs are helpful when the text output doesn’t yet show the slivers of super long periods as early. or GO HERE

A transition from El Niño to ENSO-neutral is expected in the next month or two, with ENSO-neutral most likely to continue through Northern Hemisphere fall and winter. ENSO-neutral conditions occur when neither El Niño or La Niña conditions are present.

ENSO refers to the El Niño/Southern Oscillation, which is a climate pattern that looks at the sea-surface temperatures in the central and eastern Pacific and its interaction with the atmosphere.

El Niño conditions occur when average sea-surface temperatures in a region of the central and eastern equatorial Pacific are at least 0.5 degrees Celsius warmer than average than the previous month and last or are expected to last, for three consecutive months.


Surf Climatology HERE

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.

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

Get the latest Central Pac Hawaii HERE

Note: Spectral density graph in the SNN Buoy Page HERE can show ‘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’ displayed   HERE

Links: Get the latest on the Eastern North Pac GO HERE 

For more on the West Pac Typhoons GO HERE

Common Terms:  Split Jetstream

Blocking ridge

Short-wave tough

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