This thread is for any questions relating to cyclones: low pressure systems, east coast lows (ECL), tropical cyclones (TC) etc.

There seems to be no shortage of questions since the start of STC Ului, so it seemed appropriate to have a specific thread just for this purpose.

All experts out there in forum land, please feel free to add your 2c worth through answering questions. Hopefully this thread can then become a resource in its own right.

Thanks,

Susan

Thanks snugaroo maybe i wont feel like such an idiot in here. First Question for the forum any links that you guys can share for the precipitation and other forms of charts that document the coral sea. Most i have found only show the coastline of australia.

*quickly rifles through her favourites*

Ok here we go:

ECMWF: http://www.ecmwf.int/products/forecasts/d/charts/medium/deterministic/msl_uv850_z500!Wind%20850%20and%20mslp!0!Australia!pop!od!oper!public_plots!2010032312!!/ (the forum hates this link, best to cut and paste it)

MTSAT (we are in the 'east' bit): http://www.goes.noaa.gov/sohemi/

Precipitation: http://www.radar.strikeone.net.au/?fuseaction=loops.cola%20%20%20&modelID=4&modelType=18

Lightning tracker at Mareeba: http://www.gorgecreekorchards.com.au/

Good chart for shear, shear tendency, steering winds, divergence etc.
http://cimss.ssec.wisc.edu/tropic2/real-...dvg&zoom=&time=

Oo nice one FR thanks for that, *adds to favourites*

THanks guys thats a start for me to start having a look at been diggin out the ole brain cells the last few weeks. With renewed interest.

Here's a good website nitso posted up in the Coral Sea thread before the end of last year.

http://www.theweatherprediction.com/basic/pressuretypes/

Main index: http://www.theweatherprediction.com/habyhints/

I actually have a question myself. In the WA cyclone thread there was quite a bit of discussion on the MJO (Madden Julian Oscillation) and its role in providing the right conditions for TC's to form. What are people's thoughts on this, I know there are varying opinions. Would love to spark a healthy debate on the subject

Greats Sites Thanks guys.. This thread was a great idea!

Ok ,here I go again ,into the deep end with a daft question
( to some ).

In a cyclone ( i have never been in one thankfully ) can someone describe for me what its like once it 'hits'...

I 'imagine' screaming winds, and wonder if there is HUGE thunder and lightning too??? Like a super magnified storm .I know that we can 'see' lightning stikes on the charts as 'crosses'..

...second part of question: If there is thunder and lightning, is it more scary than a bad storm ,or is it the winds that are more scary ?

You can see from my sig line why I ask ,thanks in adavnce, if anyone answers ,lol

Astra if you go to this Thread

http://forum.weatherzone.com.au/ubbthreads.php?ubb=showflat&Number=850916&gonew=1#UNREAD

Trav and Nitso sat out Ului and video taped some footage they have loaded up turn you volume up when watching it and you will hear the WIND and see the rain and wind etc.

I have expereinced two cyclones, both having lightning but no thunder. The winds are the most frightening aspect of a cyclone, together with rain, its very noisy.

Thanks Denise, I saw that thread, did look at a couple the other day,but I just went back and played them all , this post is the best for me! 853925, You can really hear the wind ,without the guys talking, ty and ty to Trav and Nitso !!! for the vid...It helps to know what you may be up against one day.

ty Tempest, i was told once that the wind in a cyclone sounds like a 747 ....
I think I just want to get myself 'informed' , so if we do get another one down this far , I can know more ,about what to expect.
ty

Whenever lightning is produced, thunder is produced as well. CC lightning is more common though in a cyclone than CG therefore the thunder is not quite as load and noise from wind and rain will over power the thunder noise. There would be no 'HUGE' lightning or thunder, well at least no bigger than any typical storm.

I remember in Tessi that the noise was dependent on wind direction, there was a roar from the wind going through trees but then if it changed slightly and got funneled between building, a 'howl' developed.

Wow that sounds really quite awful FR!

During Cyclone Ului I witnessed about 100 flashes in North Mackay (though these were electrical faults not lightning). Three of these flashes were enormous bluey/greenish glows that illuminated everything, and also coincided with the strongest wind gusts. Also after each of these glows a section of the power grid went out.

Being on the southern side of the Cyclone, winds during the afternoon prior to landfall were from the south, then as the night went on and Ului crossed the coast and travelled inland the wind direction gradually changed from S to SE to E to NE to N.

This new thread is a great idea, thanks Snugaroo. Although to get a better understanding of cyclones i think i still have a lot to learn about the weather in general so occasionaly I may have a question not directly related to a cyclone (hope thats ok).
Cyclone question - Wanda was a weak cyclone when it crossed the coast near Maryborough.
The winds associated with the system reached their peak in the night after landfall. Is it normal for a cyclone to intesify after landfall? I thought that they weakened when they hit land.

There are no such thing as dumb questions. If you have a question and you think it is dumb ask it anyway. If you don't know something then there are probably others who also don't know but have been too scared to ask.

Good idea for a thread and to help things along in the Tropical and Central Queensland thread there is a sticky for Tropical Weather links. http://forum.weatherzone.com.au/ubbthreads.php?ubb=showflat&Number=588030#Post588030 There is a mass of links in here but some are no longer working so it would be best to work through them and see which ones are of interest to you.

For those who have children and want more information you can download the Stormchasers Game. I have posted links to this in a couple of threads now. If you want to see and hear the destruction of a Cat 4 Cyclone then there is some home footage shot during STC Larry when itcrossed the coast at Innisfail. Here is the link http://www.bom.gov.au/storm_watchers_game/ It is 210MB download which would take days with dialup and chew a big hole in a limited adsl download so try your childs school library or local library. The game is free to download.

To answer the question about noise it is a combination of a lot of things but as FR said mainly the sound produced is caused by tunneling effects from natural, trees, bushes, rocks, hills, gullys etc and man made objects, but it also comes from other things as well. Tearing guttering and roof sheeting has a very high pitched wail that once heard won't be forgotten in a hurry, sharp cracks as tree trunks snap, hail like sounds as small bits and pieces of debris (twigs, sticks branches, tin cans, balls, bits of swing sets, palm fronds, rocks, sand, gravel, peices of picket fencing, roofing iron etc) are hitting the house, windows and roof and yes it can be as loud as standing behind a 747. I have been through or close to the centers of 5 cyclones (Including one in which we spent two days under a tent - hootchy- as TC Steve went passed us on a military exercise at Tin Can Bay) and each one has been subtly different when it comes to noise, lightning thunder and wind. During Tessi we had several lightning strikes within 600m of my house which we barely heard such was the noise.

We couldn't work out what a high pitched scream was during Tessi. It was comming from the corner of the house closest to the wind and we thought it was part of the roof giving way. I did a quick inspection of the exterior of the house as the eye passed ocver us and put it down to the coax cable from my TV antenna coming loose from its mounting bracket. The wind blowing through the bracket was causing the noise so I jammed the coax back in with some gaffer tape and it stopped my kids and my wife freaking out. Not the smartest thing to do climbing on to a roof in the middle of a cyclone but we all do things we look back on and say WTF was I thinking?.

The main part of the cyclone may have passed over the coast but gale force winds may still be blowing up to 36 hours after the original cyclone has passed over you. This is because the entire 'system' that contained the cyclone hasn't completely passed over you yet.

The BoM normally issues strong wind warnings for the next 24 hours after a cyclone has passed. The reason for the reintenisfication can be from sevearl factors but most often than not it is beacuse of the conditions that created the cyclone in the first place including high sea tempratures, low shear etc.