2022/23 Tropical Cyclone Outlook
It's that time of year when the Bureau of Meteorology (BOM) announce their outlook for the coming tropical cyclone season, which starts on November 1st and runs through to the end of April.
Surfers with any exposure to northern swells look forward to the announcement as an indicator for the coming summer and the prospects of swell.
With warmer than normal sea surface temperatures around Australia's northern coastlines - thanks to the combination of a negative Indian Ocean Dipole along with our third La Niña - it'll be of no real surprise to readers that we're looking at a summer of increased tropical activity both to our north-west and north-east.
The average number of tropical cyclones for the whole Australian region is eleven using the climatology from 1969–90, and the Bureau of Meteorology has a 73% chance of us exceeding this over the coming period.
Warmer than normal sea surface temperatures surrounding Australia
Breaking it down into sub-regions: the Coral Sea has an average of four tropical cyclones per season, and the BOM says there's a 74% probability of more than four cyclones developing.
This is all well and good for communities planning the tropical season ahead, but here at Swellnet we don't subscribe to the viewpoint that 'cyclones automatically equal pumping surf'.
The reason for our circumspection is because cyclones are generally small, localised features within the greater synoptic setup, and if surf eventuates it's often a hyper-focussed, short-lived pulse of large surf.
However, in saying this, an increase in tropical cyclone activity also means an increase in tropical depressions which are favourable for swell production.
So, having a 74% chance of greater than normal cyclone activity is a good barometer for an active swell season for the East Coast.
Large, raw windy swell courtesy of Severe Tropical Cyclone Oma (2019)
For those interested in the North West, the chance for above normal cyclone activity is a little lower at 70%, with the average coming in at five per season.
While the BOM is the most trusted in this space, there is another player in the tropical forecast sphere, that being the Tropical Cyclone Outlook Australia (TCO-AU).
Building on other agencies' methodologies for producing cyclone outlooks, TCO-AU generate both deterministic (TC frequency) and probabilistic (likelihood) outlooks for the Australian and south-west Pacific regions which have been proven to be accurate up to four months before the season starts (November).
Their outlooks use the 1991-2020 climatology for the Australian region - which is different to the BOM - leading to a lower count in average cyclones per year, coming in at nine.
With an average of three per year across the eastern region, they have a 79% chance of above-average cyclone activity for the coming seasion. That being 5 TCs (4-7 TCs). So though it's academic, it provides consensus that we're staring down a good swell season.
The TCO-AU also produces the chart shown below which paints a clearer example of where we can expect the cyclone activity to be focussed.
Tropical cyclone regional outlook (TCO-SP)
For the Australian East Coast, cyclones developing away from the mainland are generally better. The distance from shore allows for a greater spread of swell, with cleaner conditions, while also reducing the risk of flooding and erosion to our coastal communities.
Though it's months out of season, the current synoptic setup through the south-western Pacific is a great example of a favourable, prolonged swell generator, with a strong, slow moving high being squeezed by instability in the tropics.
Perfect setup for a wider ranging, more prolonged swell
So in summary we've got an active period of tropical activity forecast through our swell-generating windows for the coming summer, leading to more easterly swell energy, continuing on from our over-active spring.
Comments
How’s the cruisy paddle out in that picture!! I would be interested to know what the end result was there.
I paddled out in the same spot just after taking the photo.
The photo makes it look much worse than it was. There was a big deep water gutter just inside of the rocks, so 8ft bombs were detonating right besides you but all you had to do was duck dive a few white-wash wash-throughs.
I was thinking the same. Looks like one of those 'If I get caught under that section I am dead for sure!' moments.
Where did you find that TC outlook, and how can they predict the future ?
According to Surfer's Legend, Cyclones have only one central eye after making a deal with Surf God Huey. The story goes that they traded their good eye for the power to see the future and predict the day they reach landfall, where upon they transform into beastly Cyclops that feast on seachange condos, then vanish into thin air just like Huey!
We Qldurrz swear it's no legend and that one eyed Cyclones are every bit as real & beastly as Cyclops!
I surfed Kirra on that TC Oma swell, it was freaking nuts.
Ahh OMA.. memories!!! we did step
Offs at burliegh for two days straight.. best waves I have got from a cyclone.. 8-10 ft and insane sweep.. after falling on one I got swept to be in line with the Miami hill!!!
You fell on a wave with JetSki assist and ended up at Miami? Where was your ski driver?
I developed a sore big toe!
It looks like you should be getting more overtime for the forecasts FR. Certainly been a baptism of fire the last year or two.
Hot diggity damn,
get some cyclone action if and when you can.
Paging a ryder with that unused new quiver, these are the days of your lives.
psyc
The reason for our circumspection is because cyclones are generally small, localised features within the greater synoptic setup, and if surf eventuates it's often a hyper-focussed, short-lived pulse of large surf.
Tend to disagree with small, look back at Yasi, it was huge with a diameter of strong winds affecting about 700km of the Qld coast at landfall! While others may be smaller some also track well south impacting 1000's of km of coastline for days. Obviously we prefer the eyes to remain well offshore and they often do unlike the fickle little ECL's.
"...because cyclones are generally small, localised features..."
Operative word being 'generally'.
You've chosen a cyclone that hit over 11 years ago, and since then there have been over 40 cyclones in the Eastern Region alone, the majority of which fitted the description.
Insurance Australia Group + US National Center for Atmospheric Research
"Future of Tropical Cyclone Activity along Australia's East Coast"
Being their 3rd Report - following "Severe Weather in a Changing Climate" Parts 1&2
Part 1 ~ Nov 2019
https://www.iag.com.au/severe-weather-changing-climate
Part 2 ~ Sept 2020.
https://www.iag.com.au/severe-weather-changing-climate-2nd-edition
29th Sept 'News release' is shared with following...
James Cook Uni Cyclone Testing Station
Insurance Council of Australia
Climate Change Committee
TC and Future Risks Report
North Qld Strata Title Inspection Program
Qld Govt Housing Resilience Scheme > (Note: Paper covers NSW)
*Research concurs a decline in Cyclonic Activity since 1980's will continue for another decade.
*Cyclone numbers will rebound towards the end of this Century
*Current Cyclones will maintain severe intensity for longer
*Double the East Coast land mass will be impacted by Cat 5 Cyclones
*Triple the East Coast land mass will experience extreme rainfall by end of this century
*Expanding footprint exposes more southerly denser populated zones more vulnerable.
https://www.iag.com.au/newsroom/community/iag-and-us-national-center-atm...
# Investment in mitigation & Building Codes!
Further more obvious notes on 2022/23 Cyclone Outlook
These recap other recent Cyclone reports of note...
Crew will notice that only 1 Forecast East Tropical Cyclone falls within Oz control.
http://www.bom.gov.au/cyclone/tropical-cyclone-knowledge-centre/warnings/
Check any back data & see most were long peppering BOM north Tropics...not for a good while now!
Joint Typhoon Warning Centre called our only recent bat shit crazy Qld Cyclone Seth..
Twice crossed massive land forms before hitting Brizzie.
https://www.meteo974.re/Invest-97S-Tropical-Cyclone-Formation-Alert-Nort...
http://www.bom.gov.au/cyclone/history/seth.shtml
Exactly! Big Cyclones brew earlier and track from far off lands ...well before BOM get outta bed!
OZ BOM by default becomes the last to know about East Coast Cyclones as climate worsens!
Reports state each year Qld Cyclones move further East & South. ( See above Map )
https://www.abc.net.au/news/2020-03-06/cyclones-spreading-south-could-ca...
Indeed Pacific Islands are suing us for Larger Cyclones that now encroach upon their shoreline!
https://www.thenewhumanitarian.org/news-feature/2020/12/1/pacific-vanuat...
As each year warms...Cyclones can brew larger for longer in deeper southern ocean.
We could simply rotate Maps 90 degrees with North as West & East as new North...(Save a fortune!)
Result : Cyclones boycott Qld > Start in Polynesia take out NZ & wipe out Sydney...All voted for that!
Wet Tropics NZ/Sydney sues the French for Le Poo Poo Cyclone Names beyond BOM voice recognition.
Crew would've heard that NZ / Sydney are already marketing themselves as the new Cyclonic Tropics.
https://www.theguardian.com/world/2022/sep/02/new-zealand-weather-warmes...
https://www.abc.net.au/news/2022-10-06/sydney-breaks-annual-rainfall-rec...
Yes of course Qldurrz are happy to share their high'n'dry Tropical Cyclones Factsheet
https://www.iag.com.au/sites/default/files/Documents/Climate%20action/IA...
So cyclonic activity has been declining for 40 years and is expected to continue to decline for another 10 years before apparently suddenly reversing that 50 year trend ?
What changes in 10 years time to bring about that reversal I wonder ?
Insurance companies need to justify increasing their premiums somehow I guess .
TCU forecasting no cyclone to hit mainland of Aus?
Not quite, that was just their guidance for the region east of us.
Here's the forecast for Australia, re crossings you'd have to expect one or two in my opinion, but that's beyond the scope of these forecasts, and any really.
https://tcoutlook.com/australia/latest-outlook/
Thanks Craig. Eastern region predicted to cop a serious increase above the norm.
Anyone checked on the accuracy of last year’s predictions?
I’m guessing somewhere between 1 and 20 cyclones this year.
It was significantly less than predicted I think.
BOM forecast last season to have 65% chance of higher than average TC's.
The end result looks to be about that.. I'll try and find their regional breakdown.
"The 2021–22 Australian region cyclone season, despite a very high number of tropical lows, was a slightly below-average season in terms of activity, with ten tropical cyclones, two of which intensified further into severe tropical cyclones"
https://en.wikipedia.org/wiki/2021%E2%80%9322_Australian_region_cyclone_...
Apparently there were nine..according to weatherzone
while the average over the last six years is 8.5.
Last year BOM forecast ''average to slightly above average '' tropical cyclones ,,ie 11 or 12.
Actual observation was 9 or 10...which was below average , so their forecast was too high.
Without cross-checking, there were 10 compared to their long-term average of 11, but many more tropical depressions. Ie an active year of tropical activity.
I'd use their forecasts with a pinch of salt, but as pointed out in the article above, an indication of how active a swell season we may have depending on the activity to our north-east and east.
Really interested Craig?!? If we have another summer as last year might have to join the swarms up north.
unity water ( Moreton bay region) opening the gates to wivenhoe to reduce the levels to around 80% in the next few weeks, in leu of the upcoming rain/ storm season approaching.
They’re scared shitless of class action again.
ha ha most likely ,
when nature bites
where'd you hear/see that? SEQWater has the say on the dam levels.
its on f/b on the higgins storm chasers page but a post from seq water
Qldurr thanks the crew for Damming Accusations (Qld Water Hierarchy)
2005 55ML/Day $260m Gold Coast Desal
2006 133ML/Day $869m Qld Govt (Buys 50% share)
2007 Restructuring Act
2010 Gold Coast reluctantly hand over remaining 50% share to "Qld Govt Water Secure"
2011 SEQWater took over the Water Secure Gold Coast Desal
SEQ secures Water Grid for Droughts + Power Plants + Upgrades on Treatment Plants / Dams.
2013 Amalgamation SEQ Grid Manager + SEQWater + Linkwater
State owned & operated official name { Qld Bulk Water Authority } ... trade as "SEQWater"
Chair : 2018 (3yr terms) David Hamill (Former ALP State treasurer / Ed / Transport / Investment)
Qld Bulk Water Authority advise > The following Ministers Responsible
https://www.seqwater.com.au/governance
*Minister for Water
*Qld Treasurer / Minister for Investment
*Premier
Current Statement makes it clear that Qld Premier pulls the Lever.
It's actually very informative for a Resource Press Release of this kind under current politics.
13th Oct "Joint Statement by Premier / Minister for Water"
(Wivenhoe Dam Release)
https://statements.qld.gov.au/statements/96319
Qld Premier's Order (Reasons) : (It's clear that Qld Premier is 100% responsible for Water Security!)
*To ensure SEQ Safety > Threat of Flooding is very real.
*Forecasts from "BOM" + Expert Advice > Decision has been made to Lower the Dam Level
*Premier ticks off release amount = 20% release
*This increases Temp' Flood Storage for additional flood waters
*Floods Impact > Cost of Living > Announcing $55 Water rebate / 13,200L free / 1.38m homes.
Minister for Water (Handles the detail > Times / Dates)
*Decision was made under (Safety / Reliability Act 2008)
*Briefings by SEQWater / Dept of Env/Science / Dept Regional Development Manufacturing &Water
*Sat 15th Oct 2022 Controlled Releases by Flood Manual begin...(Note 2 days Govt notice)
*Next 10 days - 2 weeks "SEQWater" will drain around 116,000 ML
*Providing Flood Mitigation / Safety / Security for SEQ
*Releases are managed to minimise impact > SEQWater will adjust "Strategy"according to Rain Events.
*Now is the time to wash yer Driveway / House / Gutters ( That's the H20 Minister's advice ?)
SEQWater Release
https://www.seqwater.com.au/dam-release-update
Moreton Bay Impacts?
El Nino years...any rare Dam release brings needed nutrients to Moreton Bay sea Grass.
La Nina floods & smothers Seagrass & needs more sunlight not more Clouded River silt.
El Nino Seagrass supplies a Healthy Dugong / Turtle habitat (vs) La Nina thins out endangered species.
Dam releases wash 2 week's muddied silt down river to further smoother Moreton Bay Seagrass.
20% Dam Release will undoubtedly plume Moreton Bay to block light nourishing the sea grass beds.
Any major mankind silting now is most devastating because Seagrass grows in Summer.
Meaning: Only Shallow Seagrass is available now onward thru already scarce La Nina pickings.
Critters are then forced to feed nearer the surface via seaways & near polluted inshore City population.
Impact being a massive cull by Moreton Bay boaties
Dugong & Turtles are weak & starving to death & now exhausted hanging high & heading South.
https://www.moretonbay.qld.gov.au/News/Media/Sick-Turtles-and-Dugongs
Will politics afford SEQ La Nina mitigation manual to limit impact upon endangered species.
Well! The critters can't speak for themselves can they...
Just saying all in govt know the impacts of dam releases & also know best environmental practice.
Let's hope this isn't the final blow for local endangered species!
But the power of that captured fetch, if a TC happens to pass by or right over you, is pretty epic...
Any idea why the Indian Ocean keeps sending pulses of rain every few days across the bottom of the continent only and not further north? Seems like up north only turns into rain when the moisture hits a trough around SA / NT.
Looks like Vicco will keep getting smashed every few days for the rest of Spring at least.
Does BOM really use climatology from only two years 1969/70 , or is that an error ?
Agh, good pick up. That's an error, is 69-90.
Thanks Craig , so it is interesting to note that the 69 to 90 gives an average of 11 ,
while the 91 to 20 gives an average of 9..
Cyclones becoming less frequent over the last 30 years ?
Yep, we're seeing less TC's form but when they do, coming with greater intensity.
Craig, not sure if you've already presented this in previous articles but I just noticed on twitter this interesting SOI time series plot:
Now I'm trying to remember what the surf was like in 2011, which also seemed to be a strong La-Nina yr.
Yep, the SOI is still a valuable index for the confirmation of El Niño/Niña events though the Niño regional SST indexes give a more accurate valuation of the current heat content/sea state. Also that image is a little delayed and we've since seen the SOI dropping back..
It looks like we've seen the peak of the Niña signal in my honest opinion, and it'll weaken gradually over the coming months into summer, instead of peaking through summer and weakening through autumn as is the usual evolution. This is why this spring has been so out of the ordinary.
2011 was a crazy year for massive NE swells thanks to clustering lows in the Tasman Sea, but with Niña weakening into the summer and autumn, I wouldn't expect similar.
Qldurzz officially called Storm Season ramping Cyclone Outlook to Cyclone Watch.
Crew are Watching...well durr!
10th Dec onward > Cyclonic "activity" as predicted extends further offshore!
Activity is West near Cocos Islands < (Oz) > Activity is East off Fiji
Both forecast long range systems are worth a 2nd look as they have large fuel sources feeding them.
tbb is saying they look too small to draw such force > Therefore Cyclone season must be upon us!
https://www.windy.com/?2022120918,-19.436,129.155,4,m:dumahSi
It wouldn't surprise if either or both split into pocket rockets as there are many smaller stop/starters.
In other words areas are active & if these spin out, it won't be long before another brews up near by.
Qldurrz say there's nothing nearby, but to watch these far zones for any pre Xmas Cyclonic Activity.