Looking towards substantial rainfall for SE Australia

[Anthony Violi]

La Nina will be forned by October...and then we know what will happen, especialy if the IOD stays at least neutral or slightly negative.

Expect massive rainfall again and for us it will depend on the penetration of moisture from the North to our latitudes. Have a feeling we may see more cut offs than normal this summer.

[Ken]

Basically what I'm saying is the IOD whether Negative, Positive or Neutral only has an effect on us Winter through to early mid Spring & by November the IOD effect has well and truly finished

For those who want to know more about how, when and where a positive IOD phase affects Australia's rainfall, you might find these maps showing historical correlations handy: http://www.bom.gov.au/climate/IOD/positive/#Evolution

Here's the latest graphical summary of ENSO from the IRI (I've shrunken the image so it may be a bit blurry - in the upper right probabilities graph, red = El Nino; green = Neutral; blue = La Nina):

[Petros]

Thanks Ken, must admit that most of us focusing on "IOD" data from them are left confused.

For my 2 bobs, cant see any substantial rain down this end in next 8 days.

[Geoff]

Please feel free to mock me mercilessly, blow raspberries and wave your rear ends at me, but I have a strong feeling that the patterns are a-changing, and the endless blocking highs to our east are on the way out, to be replaced by highs sitting to our west feeding in colder wetter weather through September. There are some hints of it at the end of the runs on several models now, I also noticed that the next big high coming across mid next week tries to dive south like its predecessors bit gets shunted back north by stronger lows down south by the end of the week. I stand to be slaughtered if I am wrong by the end of September, and promise not to make such predictions again! But if I'm right.........???
Cheers, Geoff.

[droughtbreaker]

It's a good sign that EC and GFS are starting to agree on this scenario now. I reckon as we get closer to the time, (around 7-10 days), the models will become more fixed on it. This block has to end, it has been in effect for about a month and a half now with just the odd interruption from cold fronts. The Southern Ocean air masses this winter have actually been very cold, eg. the intense cold outbreaks NZ has had this winter, it's just that we have been stuck under the high ridge sandwiched between the peaks in the LWT.

Now that the inland is really heating up, the contrast between the inland and Southern Ocean air masses should move things along and strengthen cold fronts over our part of the world. What I am also liking atm is the likelihood that tropical moisture from QLD will filter down over us in N/NE flow before interacting with the front/low if it eventually comes through, (still a long way out). This really ramps up the chance of good rainfall for the entire state.

[Jayman]

Definitely looks to be firming for an event at the end of the first week of September. Latest GFS is just bizarre.

[Ken]

I've only had a chance to have a really quick and dirty look at the 2-week EC and NAEFS ensembles for just Melbourne but they're currently painting increased probabilities of rainfall for the Week 1 and 2 period in September with moderate probabilities of a spell of warmer temperatures during the 1st of of the month. EDIT: I meant to say, 1st week of the month

[stratospear]

While the block might be breaking down, there is still a real lack of polar modified air making it north towards Vic on all the models. It's almost as if the inland heat mass is pushing the polar jetstream Southward, away from SE Australia.

Lack of moisture from the NW due to the Positive IOD isn't helping. It reminds me of Spring 2006 & 2007. That said, at the far end of the latest EC run, there is a half-decent SW fetch appearing for us around Sept 8. Not that wet though, unlike what we copped on Sept 3-4 last year!

[stratospear]

Latest EC run really looking nice for Sept 6-7 and beyond. A very strong cold front, LWT in the right place, deep SW fetch. One to watch...

[Karl Lijnders]

And it will be mixing with some fairly nice warm and potentially moist air, so big rains possibly for the N and NE of the state with thunderstorms prevelant as well. I guess it is a timing thing too.

I would anticipate a large rain event in the first week or two of September with over a months rain to fall in a sitting in some areas.

[Supercellimpact]

The snow fields look to be getting up to 10cm if temps are good, the moisture will be there.

[Anthony Violi]

I think it will be a while before we see a decent rain event in the SE. Will still get some rainfall totals that will be ok, but i dont see any big rain bearing systems for at least the next month.

Last year we had cloud constantly hanging over the interior spilling in from the Indian, leading to cooler and wetter conditions through Spring. At the moment the interior is very hot due to a lack of cloud cover, so one would expect a warmer than average spring ala 2009.

I think the summer will be wet as im confident of a lot more cut offs this year similar to last year, and once La Nina is in full swing abundant moisture feeding down these latitudes again.

Another month will paint a much clearer picture, but at this stage nothing huge in the foreseeable future for us.

[Geoff]

Further to my insane ramblings of a few days ago (see above), I must say I am increasingly heartened by what I'm seeing in the models thus far. It would seem that next week around Wed 7th onwards we could see a complete turn around in the patterns, with the highs staying west of us, and the Tasman block disappearing. Of course it could be for just a week, or even not at all, but I am optimistic!

[stratospear]

GFS is in "Ramp-Up" mode for Northern and NE Vic next week. Looking like a barrage of fronts with good rain totals beginning Sunday.

[Geoff]

Looking better with every run!!! And cold too!!!

[Anthony Violi]

Indeed, and what is good is that the SST to the Sw of WA are warmer than normal so every front produces good rain without any moisture from the interior which atm is non existent.

But once that comes back, and the monsoon arrives, it will yet another summer of monstrous rainfall.

[Geoff]

Aaah, it's so good to have the old positive Anthony back, I thought you'd gone a bit soft there for a while AV!
Looking forward to your enthusiastic posts once more as things rev up this season!
Cheers, Geoff.

[droughtbreaker]

The interior of the country is dry, but these upcoming fronts, as progged by GFS, are still picking up thin bands of high moisture from the NW tropics and DPs in the low teens pretty consistently with the northerlies. If you compare the current situation with what happened in spring 2006 it is nowhere near in the same league as what happened back then when the northerlies were as dry as we see in the driest summer, pure unmodified desert air basically. I remember temps in the high 20s/low 30s and DPs well into the -ves in the spring months back then. We had a procession of very strong fronts that didn't even bring in a cloud other than cirrus, just strong wind.

I think things are basically on the way up after the most pathetic winter we have ever seen in our lifetimes, and one of the most pathetic ever. I'll even go as far as to say it practically didn't happen. 2011 will go down as the 'year without a winter'. I thought 2009 set the benchmark for that but, unsurprisingly I guess given our changing climate, we managed to outdo it this year.

Quite bizarre to have one of the wettest, cloudiest and coolest summers on record immediately followed by one of the driest and warmest winters. It is pretty much following a humid subtropical climate pattern here this year.

[daviescr]

I think things are basically on the way up after the most pathetic winter we have ever seen in our lifetimes, and one of the most pathetic ever. I'll even go as far as to say it practically didn't happen. 2011 will go down as the 'year without a winter'.

A little excessive to say the 'most pathetic winter in our lifetimes' I think Having just come back from a week up in the high country, practically every night was sub-zero and the snow at Hotham and Falls Creek was remarkably good for this time of year. I chatted with a lot staff up in Falls while the wife was skiing and I was babysitting, and many of them spoke of how frustrated they were at the shocking media hype at how bad the season was - they have had close to the quietest seasons in over a decade, yet the amount of snow does not reflect this! My experience was perhaps the best skiing I've had in Australia in the 5 of the last 6 seasons I've skied here - crystal blue skies; soft, powdery snow. Great in my opinion, I never had to queue for lifts


Yes, there's been higher than average temps in Melbourne but we all know why, and we've constantly had grey miserable skies, but that's not really be the rule for SE Australia as a whole, IMO

[Karl Lijnders]

Wonderful photo Chris and it goes to show that the media hype can be so damaging to industry.

Looking like lots of spring snow still about but likely to melt after the weekend and next week, before another 10-25cm falls with the westerly belt this time next week.

Still looking like a period of humid showery/stormy weather coming into play later Sunday for N and E VIC and then a rain increasing statewide mid week as a strong cold front and colder air pushes in.