Rare dual-hurricane event for Hawaii

Craig Brokensha picture
Craig Brokensha (Craig)
Swellnet Analysis

Hawaii is currently in the firing line for a rare dual-hurricane crossing this week: Hurricane Iselle on Thursday then Hurricane Julio on Sunday.

Hurricanes tracking close to, and crossing the Hawaiian Islands are rare events, but never have two systems come within close proximity in the same year, let alone within a week.

The reason why Hawaii rarely experiences hurricanes is due to the cold Californian Current. This current runs from north to south down the Californian coast and then joins the westward flowing North Equatorial current, keeping sea surface temperatures below the 26 degrees required to sustain hurricanes of strength forming off Mexico's West Coast.

Currently however the Californian Current is much warmer than normal (up to 3-4 degrees, as per the SST anomaly chart below) and this is flowing downstream to the waters off Hawaii. Because of this we've seen a series of tropical depressions forming in the Eastern Pacific Ocean, reaching hurricane strength and maintaining their intensity while tracking towards Hawaii.

While Iselle is forecast to move through on Thursday a second similar strength system name Julio is forecast to move in on a similar path before possibly just deflecting north-west of the Big Island on Sunday.

The satellite image (below) shows the dynamic setup across the Equatorial Pacific, with four major depresssions across the basin. Also note the presence of a strong typhoon sitting off southern Japan in the earth.nullschool surface wind chart (second image below).

Current surf forecast models have a 15ft E'ly swell from Hurricane Iselle arriving across the Big Island's Windward coast on Thursday (see here) and Oahu's northern Windward coast on Friday (see here). Hurricane Julio may provide larger swells (current forecast is 15-18ft from the east on Sunday), however local winds are likely to be a little more favourable.

Large easterly groundswells of this magnitude are quite rare in the Hawaiian Islands, so we may see some unusual surf spots spring to life that are not normally ridden.

Also worth noting is a tropical depression named Genevieve which formed off the Mexico Coast on the 25th of July but has since weakened and moved east through the Pacific Ocean to a position just south-west of Hawaii. This system is forecast to deepen into a typhoon once it moves into the Western Pacific through Sunday/Monday but may just peter out before generating any major swell for Japan.

Big Island - Windward Coast: 16-day surf forecast
Oahu - Windward Coast: 16-day surf forecast

Comments

zenagain's picture
zenagain's picture
zenagain Tuesday, 5 Aug 2014 at 8:37pm

Go Genevieve!

Yew.

wellymon's picture
wellymon's picture
wellymon Wednesday, 6 Aug 2014 at 8:18am

Quite amazing how far Genevieve has travelled, from Mexico...?
Is this common for these systems to travel that far West as opposed to Cyclones in the Southern Hemisphere..?
Seems a long way, answers Craig, cheers.

Craig's picture
Craig's picture
Craig Wednesday, 6 Aug 2014 at 10:16am

No, they ususally fizzle out Welly due to the cooler waters.

Genevieve has weakened intensified a number of times while traversing from over near Mexico and will deepend again as it moves into the Western North Pacific. As Zen said though, it looks to stay too far away from Japan to generate any major swell.

zenagain's picture
zenagain's picture
zenagain Wednesday, 6 Aug 2014 at 8:47am

Looked at the WAMS this morning.

Looks like she's going to run out of puff before she makes it to Japan. But hopefully we'll get some long period residual swell off her, just in time for the holidays late next week.

mitchvg's picture
mitchvg's picture
mitchvg Wednesday, 6 Aug 2014 at 10:10am

Thankfully where Craig has generated the content, it is not click bait.
I think the sth pac cyclone tracks are more sporadic Welly.

wellymon's picture
wellymon's picture
wellymon Wednesday, 6 Aug 2014 at 3:49pm

Click Bait...? WTF.
Cheers for the answer Craig, pretty interesting tho.
Looking at the charts and pics above I would of thought that Genevieve was still along way from Japan....?

Sheepdog's picture
Sheepdog's picture
Sheepdog Thursday, 7 Aug 2014 at 6:30pm

Gotta love mysto spots...... hope we get some footage....

zenagain's picture
zenagain's picture
zenagain Thursday, 7 Aug 2014 at 10:23pm

Genevieve has become an official typhoon (#12) hot on the heels of Hulang (#11) which is going to pass right over us Sunday arvo. Both are rated at 'very strong' at the moment.

But Genevieve seems to be doing all the right things, staying way out in the Pacific and tracking parallel northwards from Japan.

Fingers crossed but should be some lovely long lines of goodness in store for us mid to late next week.

thermalben's picture
thermalben's picture
thermalben Friday, 8 Aug 2014 at 3:58pm

Hurricane Iselle is on Hawaii's doorstep right now - just 115km SE of the Big Island and 450km E/SE of Oahu. 

From the Area Forecast Discussion for Hawaii: "Hurricane conditions are expected on the Big Island of Hawaii within the next few hours as hurricane Iselle moves ashore. Iselle is expected to bring tropical storm conditions to the rest of the state later tonight and Friday. Another round of tropical storm conditions is possible over the weekend into early next week as hurricane Julio approaches the state."

wellymon's picture
wellymon's picture
wellymon Sunday, 10 Aug 2014 at 9:50am

Any update on Iselle...?

zenagain's picture
zenagain's picture
zenagain Sunday, 10 Aug 2014 at 10:00am

I'll send an email off to a mate on Kauai and see what's happening there atm. Don't hold your breath though, norriously bad responder. Always on island time.

zenagain's picture
zenagain's picture
zenagain Sunday, 10 Aug 2014 at 10:35am

That was quick, just got a message back from my mate on the ground. His English is not so flash and my Japanese is questionable but basically a bit of a non-event. Bit of wind, bit of rain no real damage tp speak of.

I for got to ask about the surf. Probably find out in a day or so after the event.

wellymon's picture
wellymon's picture
wellymon Sunday, 10 Aug 2014 at 12:29pm

Did or are you getting waves off those Zen...?

zenagain's picture
zenagain's picture
zenagain Sunday, 10 Aug 2014 at 4:24pm

Just had a junky head-high sesh at a beachie up north Welly. The swell from typhoon Hulang is too much of a south direction for my neck of the woods, but it is picking up as we speak. The eye of Hulang has just crossed Shikoku and is heading out into the Japan sea. We'll have pretty strong winds and rain tonight but we're only going to catch the edge of it where I am.

Wednesday looking good, 8ft of easterly swell forecast at 17 secs, wind looking favourable. Could be a good day and I'm on holidays for the week. Yew!

wellymon's picture
wellymon's picture
wellymon Sunday, 10 Aug 2014 at 4:31pm

Nice one Zen, good luck mate.

Geez you really get some various weather situations in regard to surf and snow, I love Japan, love the people, love the culture love the respect from people,
Looking forawrd to going back and chasing some out of bounds ;)
Have a good surf Zenmon.

zenagain's picture
zenagain's picture
zenagain Sunday, 10 Aug 2014 at 5:27pm

I'm booked into a place up at Hokkaido Welly, Christmas through New Year. Going to check out Asahidake and Yotei san. Haven't been to Hokkaido for 5 years, be good to get back. My darling bought me a new set of high end bindings, can't wait to use them.

Hopefully spend Christmas day up to my nuts in powder.- Yee Hah!

I love it too Welly, food, surf, snow, no theft, no road rage. But I do miss home, still an Aussie at heart.

wellymon's picture
wellymon's picture
wellymon Sunday, 10 Aug 2014 at 9:02pm

Zen san,, Cool shit bro, love it.

Hahhahaha, thats weird as fuck bro, as whilst offshore a month ago, was talking with a colleague out there about this frozen water stuff...?
Well lo 'n' behold.......!
He went on a Black Diamond Tour for a week or so and came across a place called
" Asahidake" , not a ski resort just a gondola to the top and all back country with great terrain....? He said it was the shit bro. See I'm not missing a beat thats for sure;)
Fuck thats weird shit, love it.
Fill me in Zen when you get there :)

I'm a little gutted at the mo as have been watching systems with an eye, over the ditch to some of my favourite haunts but work has me fucked right up till Nov with only 5 day windows...?
Looking at Red in Feb for 2-3 weeks, belated honeymoon,hahaahaha, I mean scharlpingmoon. :)
Asahidake........................:)

zenagain's picture
zenagain's picture
zenagain Sunday, 10 Aug 2014 at 9:09pm

A touch of the nose and a knowing nod to you Welly.

Asahidake.

wellymon's picture
wellymon's picture
wellymon Sunday, 10 Aug 2014 at 9:38pm

Classic stuff Zen San

sssssshhhhhhhhhhh ;)