Tropical Cyclone Dylan blowin' in the wind
After one of the slowest starts to the Gold Coast surf season in recent memory, the first tropical cyclone for the year is expected to develop over the coming days in the Coral Sea, near the Solomon Islands. Tropical Cyclone Dylan will certainly provide some long overdue colour to the Queensland WAMs.
The change in outlook is related to an active monsoon trough across northern Australia, along with the help of a weak Madden Julian Oscillation signal over the Western South Pacific, helping spawn a tropical cyclone in the Coral Sea.
Tropical Cyclone Dylan is forecast to form in the Vanuatu region later this week and slowly drift south into a broad and established easterly trade-flow.The trade-flow itself is expected to produce 3ft+ surf across SE Qld and Northern NSW later this week, but as Dylan drifts south into this active synoptic setup, winds should strengthen and reach the gale to severe-gale-force range on top of an already active sea state.
The one factor working against the formation of a large and prolonged easterly swell event is the fact that as Dylan drifts south, the supporting ridge to its south will weaken resulting in a split fetch of E/NE winds feeding into the cyclone on its eastern flank and SE winds on its western flank.
Ideally we want an uninterrupted fetch of E'ly winds spread out nicely below the tropical system.
In saying this a strong pulse of groundswell is still expected across SE Qld and Northern NSW, peaking on Monday in the 4-5ft+ range. The rapid southward movement of TC Dylan towards New Zealand during Sunday and Monday though, will result in a short-lived one-day swell event that will back off rapidly into Tuesday and further Wednesday.
Unfortunately from Seal Rocks south, not much size is expected, with Sydney beaches only likely to see very inconsistent 2-3ft sets on Tuesday.
While the first cyclone swell of the season is expected to be quite short-lived, Dylan may pave the path for a secondary stronger tropical system less than a week later. We'll keep a close eye on this and provide running updates in the commentary below.
There is a chance this cyclone may be named June by the Fiji Meteorological Service if it forms east of 160E, but it's too hard to call at this stage.
Comments
Pretty ambitious calling it a cyclone. Tropical low, yes, but unless it suddenly bombs below 986....................
Most welcome pressure gradient though for us surf-starved up here.
Sorry, not having a dig, just a general comment.
Everyone seems to get so excited these days when a low will get around the 986 mark they just go "lets call it a cyclone" . (BOM and mainstream media beatup).
As long as I get swell at the moment I might not be so grumpy and picky.
There's no MSLP threshold requirements for the naming of a TC.
We've discussed in the past how overrated tropical cyclones generally are as 'epic surf producing weather systems'. However, this one looks pretty good right now.
No need for the apology, I'd be all antsy and on edge as well if I had the summer you guys have had.
And there is no threshold in pressure in which a system has to dip below before it's named a cyclone.
All it needs to be classified as a Category 1 system is average sustained winds of 35kt or above over a 10 minute period.
Ah, Ben slightly beat me to the punch there.
I didn't know that one guys. Thanks for the heads up. I've come from the old learnings from crusty old skippers that I worked for as a grom and they taught me the threshold was 986. Whilst 35kts at sea isn't the most comfortable conditions to be in, its not scary,bad, get the hell out of here, like a "cyclone". Splitting hairs I guess.
Geez I need a surf. Haha. I am seriously looking forward to some uncrowded waves with some size (above knee height) and grunt though.
what about SSTs above 26.5(?) and continuous rotating winds?
Yep, SST's around where the tropical depression is expected to deepen are around 28-30 degrees and it's also in a low sheared environment (weak upper level winds). At the moment there is only weak circulation and poor organisation.
So are those requirements for a TC? As designated by the JTWC(?)
There's actually different scales and criteria world wide on the naming and classification of cyclones.
Australia and Fiji follow the same criteria, and this is slightly different from the JTWC.
Australia use 10 minute averaging of maximum sustained wind speed, while JTWC use 1 minute averaging. China use a different method again, being 2 minute averaging.
haha ok I see why you kept the main article brief
One thing to also note is that it could be actually be named June by the Fiji Meteorological Service if it forms east of 160E.
So is that a boy's name? Ponting keeps calling Mark Waugh "June" on the T20 cricket and I have no idea why!
June in this instance is a female name :)
Mark Waugh is "junior" - the younger of the two Waugh twins
Ahhh yeah I've heard that at times too. Don't mind them now they're allowing their personalities to come out more
I think that may be short for "junior" as in younger brother of Steve?
Oh great, a trans gender cyclone.
Whoever "it" is, it's great timing for the save Kirra paddle out.
Geez, New Cal couldn't be in a worse spot with respect to fetch dissection in the early phases of Dylan!!! And that's the best swell window for us SE Qlders!!!! Grrrrrr!!!! Also, Craig, why do the models show such better swell on the SW/W flank of Dylan as it's tracks S/SE compared with on the S flank? It doesn't quite make sense to me as the fetch on the SW/W flank is moving away from the swell producing winds. Is it just the length of the fetch is longer on the SW/W flank compared with the southern flank? Models are also indicating the winds to be stronger on the SW/W flank compared with the southern flank? Again I don't understand this as the nearest area of high pressure is NE of NZ, hence the greater pressure differential should be more so on the southern flank (and even more so on the SE/E flank which is it) than the SW/W flank?
I'm not totally across why, even though the high pressure ridge is sitting south-east of the cyclone, and pressure gradients seem strongest there, that the actual strongest winds are being produced on the SW flank of the system.
I'm guessing this is due to the complex vertical structure of cyclones through the atmosphere.
And our model guidance is varying between model runs by about 2 - 2.2m @ 10.7 - 11.2s at the swells peak. This morning the Gold Coast forecast was 4-6ft on Monday, but it's gone back to a flat 5ft in the most recent model update.
Based on the above, I'm wondering if the models might be undercooking this one (swell models). What's your in house swell model calling for the peak of the swell for SE Qld (swell height and period)?
NY day swell last year was over cooked; it generally had a similar setup, being partially tucked behind New Cal. So maybe a medium rare swell isn't so bad of a call...
DonW, it's because pools of warm water have been coagulating in a series of NW/SE aligned eddies from the SPCZ down to the area SE of NZ. Look at the SST anomaly charts.
That is making the highs weak -hence no trade swells this summer-and not allowing sufficient pressure gradient differential with the cyclone to strengthen fetch on southern flank.
The cyclone, thus, is acting more like a cut-off system and these typically have strongest winds on W or SW flank.
I dunno about this system. Moving obliquely to the circle paths and pretty compact. Duration limited fetch. I'm keeping expectations modest.
Still, on the very positive side, it won't be a bank buster and that is a blessing.
Cheers Steve for the detailed and very informative response.
If you look at the 100-500hPa thickness, cool air is being forced between it and us. The mid level winds to the east are strong. Gradient level winds are stronger on S/SW flank... (all on Sunday). Looking at the WAMS, there is the slightest of troughs between Cook Straight and the Mid North Coast, with pre-frontal NWs.
So I guess that on Sun/Mon:
- there is a cooler air mass from the Southern Ocean; moderately cooler air from the departing (over NZ) high; the low/TC.
- So along the boundary of the sthn airmass/trough, is where the greatest friction is. And therefore greater pressure (not simply central pressure) difference is, and corresponding winds...
- The mid level winds prevent the low from moving east.
Latest GFS shows potential for an extra-tropical transition down the inside corridor aka the Tasman sea.
That could be a game changer.
Latest EC for Sunday looks damn good!!!!
i was going to suggest that its expected to transition Early . ( which will help you guys in the surf stakes ) .
Steve , that Thermal mixing is most likely due to the current " La Nada " conditions in the Pacific .
Deffo Southey.
Latest runs are looking tastier with a slowing and slight drift back into the Tasman. If there is an ETT during that stage it could be on like donkey kong.
all you weather forecasting gurus make me feel like a dunce ha ha.....i will be at port macquarie from friday until wednesday - what can i be expecting on my little break to the lovely port maq for the duration - looks like i may have picked a good time to get up there....maybe
Yeah looking pretty good for Monday BHQ. 3-5ft out of the E/NE with a moderate S'ly wind. I can think of a bunch of points and reefs that will enjoy that combo!
https://www.swellnet.com/reports/australia/new-south-wales/port-macquari...
thanks TB - looks like ive timed it well......cheers
Keep those updates coming boys, I'm heading up there sat - mon for the BDO. Now I've got a cyclone & the morning off re no Kirra paddle out. Already suggested to my accommodating wife that Monday will be worth hanging around for. Yew.
Latest updates have it coming in strongly Sunday afternoon and holding Monday. Biggest waves look to be found through later Sunday and Monday before dropping off steadily into the middle of the week.
Secondary system looks to generate plenty of swell a week later as well!
Craig does this mean we may see something in the northern beaches Sunday afternoon? Or only further up the coast? Thanks
Drew, this swell won't start filtering down into the Northern Beaches until Monday and is expected to peak Tuesday.
Tropical Depression 08F, the system that's expected to form into a tropical cyclone has just crossed the 160E boundary between Australian and Fiji met agencies and now FijiMet get the naming rights.
So Dylan has put on a frock and dolled up to now be named June later this afternoon/evening.
Winter, you could say, is coming early!
Those wams for next week look impressive. Gonna be a sustained run of swell for the cane toads.
SD, I'd be taking the long range GFS model (WAMs) with a grain of salt. GFS is certainly the outlier with respect to it's long range prognosis for further intense cyclogenisis.
The current Fiji Met forecast track has it moving right over the top of Norfolk Island (albeit as a tropical low).
She's starting to consolidate:
Tropical Cyclone June has just been named and is currently a Cat 1 system.
http://www.met.gov.fj/aifs_prods/65648.html
The Elders weather website also has a prediction of substantial ( thank you ! ) rain from Tuesday to Friday accompanied by north easterly winds around the mid north coast.
They are only predicting easterlies on Sunday am turning to east south easterlies for Sunday pm to Monday pm only.
Is the rain the after effect as June turns into an east coast low or is another system coming through causing the rain?The BOM 4 day maps show several lows forming.....
mANY rIVERS I'd say that it's related to the inland trough on NSW, moist E'lies feeding into it.
Click on your preferred region here http://www.bom.gov.au/nsw/forecasts/map.shtml and there will be a brief "weather situation" note above the forecast conditions.
craig, freeride , donweather is Dylan /june moving away from aust coast faster than first thought ......craig any changes to fridays east coast forecast notes ?
Nah, tracking as per the models have been forecast. Probably looking at a peak around 5ft at exposed spots on the Gold Coast and Northern NSW coast.
Hopefully the winds stay away tmorrow and monday few good banks around the Goldy. Looking pretty light at this stage ?
Yeah winds great Monday morning.
Last nights Big Day Out, Pearl Jams Eddie Vedder drags on stage Mick & Occy for the encore Rockin In The Free world, where they all sing & jam out the finalé. Ok our boys had tambourines, but everyone on stage looked stoked at what was going down. Eddie seemed pretty chuffed he finally got to meet Occy, Mick seemed more embarrassed than anything, & Occy, well he was just getting started!
Latest OSCAT returns looking a little more promising for the southern half of New South Wales. Will have to delve a little deeper into the data but there's a healthy region of 50kt E/NE winds here which should kick up more size than the projected 2-3ft peak for tomorrow, probably arriving a little later too- ie late Tues/early Wed.
(note: we've actually had some model issues over the weekend, and it appears we're lagging a day or so behind with updates.. so perhaps the models have resolved this upwards since then)
Blissfully happy now !! :)
Tell us more Fitzroy, no locations but what you scored.
And looks like the swell just just hit top gear with the Tweed Buoy and Byron Buoy's jumping as solid 5ft+ sets roll into the coast. Pity about the wind.
Beaches up my way were as you guys forcast around 2-3 foot. Headed out to my playgrounds around mid-morning yesterday. Around 4 foot (with the odd bigger one)with a bit of SE wind on it but still good. During the afternoon the wind swung E and then to the N and eased nicely dropping out during the night.
Woke up this morning and .............oh. As good as it gets. Mostly 4 foot with the odd 5 (maybe even 6??) footer coming through. Mostly glass out. It is still a light W to NW and under 10 kts. Bit of tide on it now.
Anyway, I've got sore arms, sore ribs and a little bit sunburnt but fuck it feels good after so long. Must do a little work now but the synoptic looks OK and I might duck back for a late arvo but definately another in the morning.
Sorry, I'm not posting photos.
:)
Nice one, Fitz.
Wow, great to hear you scored, very jealous!
Here's a couple of pics from Sunday & Monday, from two not so secret spots in SE Qld. They're just screenshots off my Instagram so they're gunna be little files.
I was really taken aback by how much difference banks can make, on more or less the same stretch of beach. From 'looks fun' to 'fark'. I guess that reflects the nature of the swell a bit too though, being a low period groundswell.
Unfortunately, the Byron spectral animation isn't working, but when I look back at the buoy graph output, the difference between yesterday and this morn was very very marginal. Maybe I didn't take enough notice yesterday arvo, but there were some long walls this morning. people were even saying the Sunday arvo sesh was smaller than the morn.
The spectral analysis has been working for me, but the update times have been very laggy (including the graph obs), 4hr's or so sometimes..
http://new.mhl.nsw.gov.au/media/animated/index.php?station=byrbow&path=i...
I can only see the 11th - 13th. Also, the last frame of the animation is very different to the current still shot above the graph on this page. http://new.mhl.nsw.gov.au/data/realtime/wave/Station-byronbay
Ah you're totally right (didn't check the dates or watch long enough to realise), but the latest/current data is correct.
Hey there fellas, mitch very good pick up, I was wondering what colours would have been on the graph yesterday and early today, any insight...?
Yesterday afternoon it went deep red and really defined indicating the strong nature of the groundswell.
is Moffats a bit of an anomaly when it comes to producing surf that feels like a groundswell? In other words, is there any surfing wave that feels softer when compared size for size? I get more rolled on 2ft beachies than than 5ft Moffs.
Ha, I've made the mistake of frothing on out of date data before, so now I always check. What I'm interested in is comparing the max period from straight off the spectra; the Tp in text beside the spectra; and the Tp1 on the graph. Often the spectra (right term?) shows energy with a period higher than Tp1("peak of the energy spectrum")... I can't help but think of the barrage OC copped on the forum, so I'll keep the rest of my thoughts about judging surf from wave buoys to myself...
Well I have to take my hat off to Access G. It's been forecasting TC Dylan's FNQ crossing for many days now. Way before EC and finally GFS have jumped on board.
I'm all geeked to be honest...
Welcome TC Dylan!
TC Dylan's gone from a tropical low to a Cat 1 to a Cat 2 in just six hours. Very impressive.
http://www.weatherzone.com.au/news/tropical-cyclone-dylan-upgraded-to-ca...
the Central Qld buoys went ape shit! With a brief facebook trawl, I didn't see any surfing going down though... I don't know how to post a pic though unfortunately.
On another note... TC Edna wtf?
Mitch Very Good (VG) ,
I sussed this the other day being Welly tech phobia,.....??????
Go to "Igmur" google, log on etc,
Drag a pic into it, when it is uploaded, click on it, then click on the little page looking thing next to BBCode (message ,boards and forums)
It should say copied or copy.
Then go to where you want to put it, paste it where ever you want.....? It will come up as words but once you comment it will come up as a picture...............
Well I hope that works, worked for me, I dont even know why Mr tech phobia is explaining this, hahaha
Good luck champ :)
I've seen Mackay looking like Dbah on deep and strong tradeswells, once. Well almost Dbah. Anyway. Thanks Wells. I'm really reluctant to sign up to another website, but the google sign in is pretty handy once you get past creating the login.
BTW, it's "iMGur" ;)
Thats him