ENSO & IOD

Page 4 of 4 Previous  1, 2, 3, 4

View previous topic View next topic Go down

Re: ENSO & IOD

Post  Power Storm on Wed Nov 04, 2009 2:05 pm

Thats the biggest concern I have had about this Summer. The heat just dry's things out, it certainly looks like a warmer than average month or so ahead, many records to be broken no doubt. Even though some parts of Victoria have done really well, it does not take that much to turn it dry and bleak again, setting the state up for another major bushfire season. The soil below is still very dry, and it seems my area (bar the NW of the state) is the only parts of the state that have fire restrictions on currently! I still think we will have a good storm season right up till the end of Autumn from now (lets hope wet thunderstorms and not dry), but it does look like drier conditions developing.

Oh and John, I would say it would be classified as a strong El Nino now, despite its strange start.

Power Storm

Posts : 703
Join date : 2009-05-18
Age : 23
Location : Simpson South

http://www.australianweathernow.yolasite.com

Back to top Go down

Re: ENSO & IOD

Post  hillybilly on Wed Nov 04, 2009 5:17 pm

Watto - yes we would expect the El Nino to break down over summer into autumn. The breakdown can happen very quickly (such as in 2006) or can drag on into autumn. This is partly due to unpredictable weather - the 2006 break down was associated with a sustained surge in the trade winds.

Yeah A Neutral IOD helped this Winter and early Spring when you would normally get a Positive IOD associated with an El Nino meaning Cool waters NW of Oz which didn't happen this year.

Word getting out into parts of the public/media that this El Nino is a "Modoki El Nino" know much about it guys?

Johnno I think the IOD really saved our bacon this year in the south. The pattern of rainfall for winter to now has been pretty classical El Nino with a neutral IOD. This pattern sees dry conditions through QLD/NSW but tending towards average across the south. It could have been a truly horrible year for all if this hadn't happened (though some areas were not so lucky such as around Melbourne which has experienced a horribly dry year).

BTW RE Modoki a lot of climate scientists don't buy the "modoki" idea - and I'm one of them. I think El Nino events come in all flavours and it makes little sense to try to give them one of two names ("modoki" or "normal/non-modoki") - I liken it to trying to summarise every summer/winter/spring/autumn as being "normal" or "abnormal" - makes no sense - every one is different. There is no need to simplify the "system" as climate models do not care about simple patterns - they take the current state of the ocean/atmosphere system and predict forwards in time capturing the full complexity.

hillybilly

Posts : 742
Join date : 2009-05-18
Location : Ferny Creek

http://www.bom.gov.au

Back to top Go down

Re: ENSO & IOD

Post  Johnno on Thu Nov 05, 2009 2:32 pm

Yeah thats what I think DJ its all El Nino to me I think some people are getting to techincal with it.


NOAA Sub-surface anomalies past 3 months..

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/wkxzteq.shtml

Johnno

Posts : 741
Join date : 2009-05-18
Age : 39
Location : Near the Showgrounds

Back to top Go down

Re: ENSO & IOD

Post  Johnno on Fri Nov 06, 2009 9:36 am

Ssts off the NW coast of Australia have really warmed up in the past week to become above average temp wise this may possibily be a good thing in the long run for us.

I have Noticed a pattern with El Nino years that ssts off the NW coast of WA begin to suddenly warm rapidily in Early November happend in both 2002 and 2006 only differance to this year though is since June/July ssts remained warmish up there only October it got cooler than normal where the other 2 years the were cooler than normal from Winter to end of October but once again right on Cue 1st Week of November a sudden warming up there, if it goes anything like the other 2 El nino years I expect this warming to slowly spread Eastwards through the North coast of NT and into Torres Straight and the Gulf of Carpentaria and eventually into the Coral Sea the next few months as the El Nino gradually begins to slowly breakdown


http://www.weatherzone.com.au/climate/indicator_sst.jsp?lt=wzcountry&lc=aus&c=ssta

Johnno

Posts : 741
Join date : 2009-05-18
Age : 39
Location : Near the Showgrounds

Back to top Go down

Re: ENSO & IOD

Post  Karl Lijnders on Fri Nov 06, 2009 6:23 pm

Certainly seeing that Indian Ocean heating, impact the W Coast troughs over the early part of the season. This gives us a great deal of expectancy that things may not be so bad this summer for the region with more small to moderate rain events and classical thunderstorm outbreaks.

BTW keep an eye on moisture at both sides of the country. I expect this to fold over and come down in the northerly advection by mid to late next week and re-enforced again as a LWT of some magnitude works towards the region in 10-12 days time.

Very hot weather to come.
avatar
Karl Lijnders

Posts : 1472
Join date : 2009-05-17
Age : 32
Location : Knoxfield, Victoria

Back to top Go down

Re: ENSO & IOD

Post  The Watto on Sun Nov 15, 2009 8:36 am

Hi Guys, I was wandering if any of you could make it clearer on the impact this El Nino is likely to have on South Australia between now and March. I apologise for my limited knowledge on this subject but I was reading the latest round up on the BOM website and the following was noted in the "iN Brief" section

"Most leading international computer models surveyed by the Bureau predict that El NiƱo conditions will persist throughout the southern hemisphere summer".

Correct me if I am wrong but I think that the last 2-3 El Ninos have peaked around December and broken down around Jan and Feb with good rainfalls. But is this El Nino, judging by the above comment, not likely to break down til around March time, so in my eyes that looks like it could be a summer of low rainfall and above av temps again, which would be devestating!

Any info appreaciated on this
Cheers, Michael

The Watto

Posts : 30
Join date : 2009-10-23
Location : Mentone

Back to top Go down

Re: ENSO & IOD

Post  Johnno on Tue Nov 24, 2009 12:21 pm

Well Watto looks like the lastest BOM 3 month outlook updated today for Summer (Dec-Feb) are going for a Neutral Summer interms of rainfall if anything mabye slightly more chance of being wetter than normal through Central, Western and NW Vic & South Australia (50-60% chance)

Also the BOM have pulled back on being a hotter than normal Summer with more average temps more likely expected and theres a good chance the Minimums may be below average as well.. Anyway here are the maps updated today..


http://www.bom.gov.au/climate/ahead/rain.seaus.shtml


http://www.bom.gov.au/climate/ahead/temp.seaus.shtml



This does not mean we will not get anymore heatwaves this Summer but it may be more of a normal Summer and perhaps we won't get too many more and not as lengthy as intense thats the way I read it.

This doesn't suprise me as BOM had preety much the same maps in both years 2002/03 Summer and 2006/07 Summer interms of rainfall % chance and temps and both those El Nino Summers turned out to be close to what BOM thought so hopefully they are right again but time will tell.

Off the record been told by my mate Anthony/Malleefarmer that the box trees are flowering full on up in NW Victoria even more so than this time last year so mabye next year will be even better than this year up there interms of rainfall fingers crossed.



John.

Johnno

Posts : 741
Join date : 2009-05-18
Age : 39
Location : Near the Showgrounds

Back to top Go down

Re: ENSO & IOD

Post  Karl Lijnders on Tue Nov 24, 2009 1:19 pm

Could be thanks to more intense rainfall systems like this weekend gone. It is more likely than not that we will get some more rainfall along the lines of what we have experienced.

The natural signs including the rain trees (silky oaks) flowering have delivered the past 4 years they have flowered. Before those years they went dormant.
avatar
Karl Lijnders

Posts : 1472
Join date : 2009-05-17
Age : 32
Location : Knoxfield, Victoria

Back to top Go down

Re: ENSO & IOD

Post  droughtbreaker on Tue Nov 24, 2009 6:24 pm

Silky oaks would be responding to the more humid conditions we have had recently. In QLD (where they are native) they respond to the hotter and more humid weather by flowering as it is an indication of the wet season ahead which is the best time for seed germination and success. Obviously down in VIC we do not have a summer wet season and the air is usually drier with lower rainfall, so if these trees are flowering well now it doesn't necessarily tell us anything about what will happen down the track, it is just telling us that we have had a sudden period of unseasonal sub-tropical type weather.

Jacarandas do the same thing, they are flowering now in Melbourne thanks to the early season heatwave and humid spell we have had and now the heavy rain. Most other years they start flowering a couple of weeks later, this year they are early.

The silky oaks aren't doing well here atm, mainly because they don't like cold climates and the drought combined with that has knocked them around. There are some around here in gardens that have grown fairly tall but they rarely look particularly healthy. In previous years where we have had better rainfall they have flowered a lot better.

I'm not sure about the box trees in the Mallee. (BTW is this 'Grey box' or some other species?) One thing I can't understand though is how plants and animals can predict what the weather is going to do, particularly long term. That is sort of getting into the supernatural IMO. Not disrespecting others' opinions or anything, but it just sort of sounds like magic, or mysticism that a living organism can know what the weather will do for an extended period of time into the future. The future doesn't exist yet and is subject to a huge number of variables and combinations of events happening that are changing all the time. We can predict what is more likely by studying ocean temps, various oscillations (ENSO, IOD, SAM etc.) but we can only give a statistical prediction like the BOM does, eg. 50% chance of above average rainfall. If a tree is flowering more prolifically than usual then that is a reaction to the current or recent climate and other related factors such as soil moisture and temperature etc, also the trees may simply be healthier this year than other years for whatever reason and therefore able to flower better.

droughtbreaker

Posts : 640
Join date : 2009-05-17
Age : 35
Location : Mount Macedon (520m asl)

Back to top Go down

Re: ENSO & IOD

Post  Karl Lijnders on Tue Nov 24, 2009 8:07 pm

Thanks Andrew Smile

The silky oaks look amazing here. They are so tall and doing really well. A few scraggly ones but there are plenty of 40m ones here doing really well and very orange at the moment. Just a note that it has been the last 4 years that we have had them bloom furiously and it has rained heavy in spring and could be due to increased humidity but they only bloomed with warmer wetter and drier air 2 weeks back so who knows. But it is interesting!!
avatar
Karl Lijnders

Posts : 1472
Join date : 2009-05-17
Age : 32
Location : Knoxfield, Victoria

Back to top Go down

Re: ENSO & IOD

Post  Johnno on Wed Nov 25, 2009 6:43 am

Hi Andrew, I really believe the Silky oaks respond to whats going to happen not the heat and humidity as most of october was quite cool and dry alot of the time with low humidity it was only the last few days that we had high humidity and the thunderstorm outbreak but I kept a close eye on the trees right through October and they were heavily budding by Mid October for there flowering period in November (I even took a pic on my phone and sent it to Karl when they were in bud weeks before November started) there wasn't any heat around nor humidity or which to me shows there not responding to heat/humidity rather what will happen in the coming month.

Johnno

Posts : 741
Join date : 2009-05-18
Age : 39
Location : Near the Showgrounds

Back to top Go down

Re: ENSO & IOD

Post  Sponsored content


Sponsored content


Back to top Go down

Page 4 of 4 Previous  1, 2, 3, 4

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum