Victoria - Trough - Potential heavy rain 15-16 March 2012

[I_Love_Storms]

EC progging a pretty vicious collision of colder air with a warm humid airmass late next week (Thursday into Friday). BOM also has storms on the forecast for next Thursday and GFS throwing up some interesting runs with quite a bit of rain. Something to keep an eye on but looks like another producer IMO with potentially good storms if the timing is right.

[Anthony Violi]

Looks like it might only get a partial infeed as i suggested a couple of days ago, then roll over the ridge and give us a better chance on a second system.

Still, 50-100mm looks likely through a good portion of the state.

Aside from that, looks like we are setting up for another large scale event on the western half of the country which would offset the eastern floods nicely.

By months end the whole country should be well on the way to being submerged.

[Jake Smethurst]

This is something to keep a very close eye on as it could worsen the situation of the already saturated areas of parts of northern and eastern Victoria. There will be rainfall totals of around 50-80mm (at this stage) somewhere across Victoria during the Wednesday/Thursday period. Models are still varying with the timing and strength of the upcoming trough, but at this stage one would estimate it's arrival into western Victoria during Wednesday afternoon. Also the risk of a cut-off low forming with this which could be a problem as well, EC showing this and GFS hinting at it. Watching this very closely.

By the way, all AWF forecasts including the Audio Briefing have been updated here: http://www.theaustralianweatherforum.com/mainpage.html

[Anthony Violi]

Looks like there will be an inland sea developing through Western Australia as well. Soon you may be able to jet ski from Perth to Sydney.

At this stage, will be a large scale event, should see 100mm falls through Victoria, good chance SA and WA will see significantly more.

What i do think will happen is that the models wont pick up on this for a few days as they have the DPs at the surface too low, though CMC has risen the stakes significantly tonight.

And another thing, the whole sequence may be "squeezed" against the ridge, meaning falls will be very large.

[Geoff]

Looks like there will be an inland sea developing through Western Australia as well. Soon you may be able to jet ski from Perth to Sydney.

Classic! I have to say AV, your imagery of late has been truly world class!

[Anthony Violi]

Lol yes Geoff try to keep it entertaining.

But watch the models start to wake up shortly and promise another historic event.

Could even eclipse the current one.

[johnno]

Oh dear EC has 60-130mm in parts of Northern Vic and along the entire Murray almost later next week and Weekend in this mornings run, GFS also starting to increase rainfall again.

[Anthony Violi]

People should leave those areas right now, its going to end very badly there.

GFS increased rainfall to 100mm~ across most of Vic, though i think its not high enough.

But looking at the DPs forecast, i can see why. They still have work to do but will wake up shortly when they increase them, and rainfall will also increase.

[sparra]

So is this event/events still mainly to effect the central/north east or should we here in the west cop some action this time around???

[stratospear]

GFS and EC are fairly convergent in their forecasts for next weekend. It's not going to be pretty IMO.

At least the Hume dam (83%) and Eildon (94%) aren't full atm, but they could quickly fill, overflow, and cause significant problems downstream for quite a while.

One thing that's caught my eye is the amount of heat in WA atm (Perth 40 degC!!!). It'll be interesting if that gets caught up in the mix and adds fuel to what's on its way.

[johnno]

Hume dam has gone up neally 20% in the past 10 days from 63% so its well on its way of closing in on full as for Eildon its the highest its been for this time of Year (when normally its at its lowest point of the Year) for many many Years if not decades! 94% Eildon is at the moment even this time last Year when we had an extremely wet Spring of 2010 and Summer 2011 it was 83%

[johnno]

Just checked the historical graphs/data last time Lake Eildon was this high in March was in 1993 (though we had a very dry Autumn that Year so Eildon went down before it went up again later in the Year) and before that was in 1974 so as you can see its very rare to see the dam at 94% in March considering its not even the filling season yet.. Which to me spells trouble once the filling season begins.. My point is Lake Eildon is at a once in 20 Year situation at the moment or actually 19 Years to be precise!

[stratospear]

It already appears Goulburn-Murray water are aware of what they need to do. Not sure if it will be enough though:

http://www.g-mwater.com.au/news/media-r ... rages.html" onclick="window.open(this.href);return false;

"Releases from Lake Eildon will meet downstream requirements as well as reduce the storage level more quickly than what would occur if releases were only for downstream demand. The releases will commence at 4,000 ML per day which is well within the normal operating rates of release for this time of year. Water will be released through the power station, not the spillway gates," Dr Bailey said.

[Meso]

Massive downgrade from GFS...

From this...



to this...



No where near as keen on storms as it has been for the last several runs either.

[Anthony Violi]

This is going to be the concern. I can see this being a 3 pronged system, beginning Thursday and ramping up late weekend into next week maybe for 7 days.

The danger will the GFS scenario of 00z. if it holds back the LWT it will connect with a lot warmer and moister air. Its the position of the cyclone thats chopping and changing the output. In fact this run looks like its really starting to ramp up the falls through WA, wait to to see the diagnostics and you will see the Dps are now higher.

Need another day or so to nail the cyclone before it gets set on the trajectory of the flooding rains to come.

[Geoff]

Meso, I think that GFS 0z chart just shows the approaching cut off trough being held back by the ridge for 24-48 hours, before it bombs as a cut off low over us on about Monday. As Anthony has suggested this could help the tropical infeed to really boost rainfall totals.

[johnno]

Yeah its not that the rainfall has dissapeared its still there but held back to our West. EC is the key with next week and keep an eye on UK and JMA, as much as I have said GFS has been performing better lately it usually does very poor with cyclones/tropical lows EC handles them alot better and the direction they go so for this coming week I am looking at other models more closely rather than GFS in particular EC.

[Meso]

Yeah, I did have a look at the full aus map and noticed a lot of rain still back towards the NW, but I'm no expert at reading these synoptic setups so wasn't sure whether that's where all the rain was gonna fall or if it just meant it might take longer to get here. You can still see clearly the moisture getting dragged in this direction from wa. Opens the window for storms on the wknd if the whole thing gets pushed back a couple of days at least.

[stratospear]

Latest EC has system coming in on Thursday with around 50mm for Bendigo that day.... Next to nothing for Southern Vic. Confusing.

[Gordon]

06 GFS back on board with a vengeance.