Hurricane season 2026

[Durian Fiend]

Developing El Nino conditions suggest above average chances for tropical storm development this year.   For a more in depth discussion, the following is copy and pasted from Harry Durgin's post on the Facebook group Puna Weather.

"There is an elevated chance for tropical cyclone threats to windward Hawaii island this summer and fall.

As of April 23, 2026 sea surface temperatures (SSTs) to our south are about 3F higher than normal (SST anomaly chart). Far to our south over the ENSO region SSTs are also rising (ENSO 3.4 chart). Models indicate that SSTs will continue to rise in the ENSO region through the summer, possibly leading to a strong El Nino next fall/winter. Regardless of the strength of the future El Nino state, the current situation is that we're in a period of transition towards an El Nino. The transition period is characterized by rising SSTs, whereas a mature El Nino state is characterized by elevated SSTs, but not necessarily rising.

In February a trend of increasing temperatures in the ENSO 3.4 region has been fairly steady, leading to good model consensus that we are heading towards an El Nino state. This transition was reinforced by multiple recent cyclones, two in the southern Pacific and one in the northern Pacific, Sinlaku, initiating a strong westerly wind burst and leading to subsurface warm water being pushed east. If this wave of warm water surfaces in the ENSO region it will reinforce the rising SSTs there.

The most likely responses to already warm waters near our island and a transition towards El Nino are:

• Hadley subsidence shifted east
  
• TUTT shifted east
  
• ITCZ shifted north
  

leading to:

• more cyclone activity in the central Pacific
  
• more humidity
  
• less rain
  
• less frequent trade winds
  

There are two circulations important to our upcoming tropical weather season. The Walker circulation (ENSO) and the Hadley circulation (trade winds). The Walker circulation is oreiented east-west and involves a coupling between SSTs and atmospheric pressure in the tropical Pacific (we're a little north of the tropics). The Hadley circulation is north-south and is driven by convection over warm SSTs near the equator. The convection causes air to rise and spread out when it reaches the top of our atmosphere, the tropopause. Spreading air in the northern hemisphere travels far to the northeast and descends when it gets cold from being in the upper atmosphere, this is the source for our semi-permanent northeast Pacific high which drives our trade winds. Warmer waters over the tropics (ENSO region) will drive more convection, but this doesn't typically lead to stronger or more reliable trade winds for us for two reasons. The high is often shifted farther east during the transition and El Nino periods. Warmer SSTs locally create moister air which is more buoyant and pushes against the descending air making the high pressure weaker. Both add up to weaker and less reliable trade winds. That statistically shows up as less rain, possibly leading to drought conditions in the fall.

Now let's talk about cyclones. There are two main sources, the eastern Pacific (long haul), and central Pacific (homegrown, these are my personal terms). The long haul storms need to make a long fraught journey where they are likely to encounter colder SSTs, mid-level dry air, and hostile wind shear. We already have warm SSTs, like 2015, when we saw a parade of storms make the journey degraded, but still partially intact. Mid-level dry air is associated with the descending branch of the Hadley cell and that is likely to be weakened and shifted east, so either normal or less than normal impacts. Wind shear comes from multiple sources, but one is the TUTT, a mid-oceanic trough in the upper atmosphere. High winds associated with the TUTT can rip a cyclone to shreds. If the TUTT is farther to the east, it could offer less protection. All in all it seems we're looking at a heightened risk of these long haul storms.

The homegrown storms present a risk when we see westward moving tropical waves in the ITCZ amplify. The risk of one of these waves spawning a cyclone is increased when there is MJO enhancement. Waters to our south below 15N are currently warm enough to support cyclone formation. The next MJO pulse is forecast for 4 to 6 weeks from now. This would match up with the official start of the central Pacific hurricane season on June 1.

Our mountains do impact cyclones that pass over or near our island. They strongly degrade storms that pass over, offering significant protection for our more western islands. Research on Taiwan cyclones indicates two impacts on close call tracks. One is enhanced rainfall over the mountainous terrain releasing a tremendous amount of heat causing the air to rise and pressures to lower locally, leading to a deflection of the storm towards the island. The second impact is from higher wind speeds near between the mountains and the storm's center due to a funneling effect. This also leads to lower pressure nearer the island and again results in a deflection towards the island.

In summary it looks to be humid with less than normal rain this summer. Also our tropical storm season could get an early start this year. And, next fall could bring drought conditions."

[MyManao]

Our mountains do impact cyclones that pass over or near our island. They strongly degrade storms that pass over..

Finally! After years and years of our illustrious "scientist" vehemently saying otherwise, our Maunas get their due!

[TomK]

Our mountains do impact cyclones that pass over or near our island. They strongly degrade storms that pass over..

Finally! After years and years of our illustrious "scientist" vehemently saying otherwise, our Maunas get their due!

At least try to be honest. The full sentence is:

"Our mountains do impact cyclones that pass over or near our island. They strongly degrade storms that pass over, offering significant protection for our more western islands." 

[Bolding mine]

Your claim has been that the "magic mountains" protect the island of Hawaii.

---

My Manao's response was posted in another thread. It was:

"You're so full of nonsense.. and your ego is so inflamed that you think you walk on water. All you spew is BS. I have explained my point every which way from Sunday.. and nothing has anything to do with magic.. other than the magic you think you wield over folks here with your nonsense. Grow up Tom."

If I'm wrong, you'd expect a reasoned response here, but the reply is just a bunch of insults and, as usual, a straw man. I assume it was the reason it was posted in the bicker board thread rather than in this one.

[Durian Fiend]

As I recall, it has been claimed in the past that our mountains somehow tend to steer storms away from hitting us on da Big Island. What Durgin says above is actually the opposite.

In his discussion of "close tracks" he claims there are two factors at play that deflect the storms "towards the island".

[TomK]

Thanks for pointing that out, you're right:

"One is enhanced rainfall over the mountainous terrain releasing a tremendous amount of heat causing the air to rise and pressures to lower locally, leading to a deflection of the storm towards the island. The second impact is from higher wind speeds near between the mountains and the storm's center due to a funneling effect. This also leads to lower pressure nearer the island and again results in a deflection towards the island."

In addition, many years ago I was in a meeting with representatives from all the observatories and the team at UH's Mauna Kea Weather Center (MKWC - http://mkwc.ifa.hawaii.edu/). The Director of MKWC made a presentation at that meeting about the effects of the wind shadow downwind of Hawaii Island. IIRC, one of them was a potential drop in air pressure SW of the Big Island, which might cause hurricanes passing south of the Big Island to divert north towards Oahu and Kauai.  I'll check whether the paper was published.

Interestingly, Hurricane Iniki did exactly that back in 1992. If that's the case, we have two mechanisms that cause storms to head towards the Big Island, which would protect the other islands, but another that creates a threat to the western islands because of the mountains on Hawaii Island.

[Durian Fiend]

The developing El Nino could be the strongest in 150 years! Therefore the potential for a very dry winter is a consideration.

[ironyak]

My favorite moniker used so far is "Godzilla El Niño".

What can we really do against ゴジラ (Gojira)? I guess nothing, so bring on the dancing kaijus!

[MyManao]

What Durgin says..

I have yet to be impressed with Durgin's powers of deduction.. and will add..

Considering that the strongest cyclonic system to hit Hawaii island in 'recorded history' (a loosely used term to mean white man’s history) was Iselle, which wasn’t even a hurricane, or if it was was just barely (even though the Albizia made it seem otherwise) and its center didn’t make landfall other than to graze the southern tip of the island and then immediately go offshore again, and through all that had only a glancing interaction with our Maunas, any talk of how hurricane force winds interact with our mountains is speculative. And, without more definitive data* all we can do is continue to speculate..

While we are, speculating, here’s a study of what may very well have been one of the biggest, if not the biggest, storm to actually make landfall here in a very, very long time. It certainly exceeded Iselle..

From: https://journals.ametsoc.org/view/journa...0333.1.xml

Hurricane with a History: Hawaiian Newspapers Illuminate an 1871 Storm

Whose Abstract reads..

High literacy rates among Native Hawaiians in the nineteenth century and publication of more than 100 Hawaiian-language newspapers from 1834 to 1948 produced the largest archive of indigenous writing in the Western Hemisphere. These newspapers extend our knowledge of historical environmental events and natural disasters back into the early nineteenth century and deeper into precontact times. Articles reporting observations of meteorological events allowed the authors to reconstruct the track and intensity of an 1871 hurricane that brought devastation to the islands of Hawaii and Maui and to discern historical patterns of droughts and floods in Hawaii. These findings illustrate the value of Hawaiian-language newspapers as resources for science research and science education.

This is a great addition to the consideration of the history of hurricanes here. With serious estimates that the storm came through the island, along the Hamakua coast, over the Waimea saddle, and onwards through the Maui roads at Cat 2 strength. The amount of damage the same would wreak today is considerable. Here’s a map of the estimated path..



It certainly is something for those that think our Maunas offer unchallengeable protection from sever weather systems to chew on. Although without the suite of remote datasets we have today there’s no telling how that system got to the Hamakua coast. Whether it was a direct hit from out of the east, or a glancing blow that would have done in Hilo except for the steering influence our Mauna’s presence add to the forces at play, is anybody’s guess.

I have always pointed out that our Maunas exert a considerable amount of influence, especially when compared to the open ocean, in that cyclonic systems tend to be, at least in part, steered by their presence. Of course there’s other factors, but they too often hinge on the presence of the island. It just plainly cannot help but be. The islands are here, they affect the world around them. And now, with remote sensing, we’re able to understand more as each system exhibits some amount of behavior commiserate with the NWS’ statement I quoted earlier in Kiko’s campaign..

https://punaweb.org/forum/showthread.php?tid=23639&pid=357747#pid357747

Where I highlight their statement..

Historically, cyclones approaching the Big Island from the east can slow and deflect northward as the island terrain disrupts the low-level flow and alters the steering currents.

Seriously, with our mountains standing nearly 14,000 feet tall, our volcanic peaks (Our "Magic Mountains" as PaulW called them) act as physical barriers that disrupt the low-level circulation and structure of a tropical cyclone. Initially this changes the symmetry of a storm, which as it gets closer can cause it to weaken, and, break up as it moves westward towards the other islands. Additionally, as a storm's moist air is forced up the mountain slopes, it cools and condenses, leading to extreme rainfall, even if the storm's center never makes landfall. And, sure, it’s easy to imagine specific instances where the local winds increase. But to think the land masses do not have a chilling effect on a system as a whole is just silly. And, as I said before, how the wind will actually behave in any given situation is purely speculative when we consider how little historical data we have to speculate with. Modelers can create all kinds of models, but even the professionals with all those spaghetti lines for the most part are playing pin the tail on the donkey for anything other than the first so many hours of any predictive period.

As to storms that pass to our south and then, after passing the island turn to the north, we have seen this more than a few times. And, I would contend that more than saying the Maunas cause this, they prevented the storms from turning to the north as long as they are under their influence, and then after they passed they were free to follow that trend. But, regardless, to say one way or another as if one knows better than another is pure folly. We’re all no better than speculating. And, OMG, ain’t it fun!?!

BTW, I don’t like hurricanes, the stress of the waiting and uncertainty, and the potential danger all conspire to cause me to take them seriously, as I would caution anyone to do.


* How many examples of something would it take for our understanding to be “definitive”? Way more than once, or twice. So even with a direct hit, just one, which we haven’t had in our time, we’d still be playing a guessing game. Not as much guessing as we are now, but still..

[ironyak]

Several years back, while spending some time up in Hawi, our host mentioned something about how the Maunas protected the island and how no hurricane had made direct landfall and how safe from storms the North Kohala area was.

Meanwhile, each morning I was drinking my tea and reading on the lanai their copy of Kohala ʻāina : a history of North Kohala, which has a section detailing that 1871 storm with the trees uprooted or snapped off at the trunk and hundreds of homes and sugar mill buildings damaged.

Always good to double check the stories we tell ourselves against the actual historical record.



How many examples of something would it take for our understanding to be “definitive”?
Given the unprecedented times and conditions we live in, the past may offer little guidance as to what we can expect. Likely going to need to find new terms to append to known phenomenon - plenty droughts, choke rains, and sumo floods (sumo!) to go with our Godzilla El Ninos! (so what's to come next - a Mothra or Biollante La Niña? ;)

[HereOnThePrimalEdge]

Seriously, with our mountains standing nearly 14,000 feet tall, our volcanic peaks (Our "Magic Mountains" as PaulW called them) act as physical barriers that disrupt

Speaking of physical barriers.  Most of us are familiar with the Cook Island Pines on the summit of Lanai Island.  They were planted to grow and reach a higher elevation to act as water collectors.  The additional height is enough to add a substantial amount of water to the island’s water supply from the trees.

https://everything-everywhere.com/the-pi...-of-lanai/

Now obviously we can’t plant Cook Island Pines on the summit of Mauna Kea, it’s too dry and too cold.  But what if something else could raise the elevation of the mauna, adding to its possible effect as a physical barrier?  To protect our island even more from hurricanes?