The Australian Weather Forum

I thought we might as well create a thread to separate this event from the current April weather, as there is going to be plenty to discuss. As usual with these major synoptic scale systems, the upper low will call all of the shots. 120 hours out, models differ on the exact location of where the cut off upper vortex will be positioned. Most models are projecting the upper low to balloon north and assist in interacting jet streams around S.A. An associated moisture rich surface low could spawn anywhere from S.A, NSW or Vic around late Thursday in a currently unknown location. Plenty of downgrades and upgrades to come

Thanks JS. It's a pretty map

Looks like a lottery. Anything from 0 to 50mm is possible...

Downgrades - most models show the low further to the west and slipping south after that. BOM rainfall totals adjusted downwards too. Hopefully it wiggles back to a more favorable rainfall event for all - we really need a proper break.

And then 00Z EC throws up a 60mm deluge for us...

Lottery.

A mere 50mm Wed/Thursday for us .

Possible precip totals are up and down, up and down, but that usually means we're guaranteed something, so my hopes are rising

Handy 8mm yesterday, which will help anything that does fall to sink in.

Is this another of those 'autumn breaks' that seem to be our salvation? (the charts are looking good)

Latest batch of Progs all look very good. Widespread 20-80mm falls. Devil will be in the details, but looks like a quite general state wide event, and quite cold as well so a proper winter spell Hoping this one jump starts our May total.

After only 10mm april total at Macedon i hope this one comes off. It is getting bad out here.
I have faired a little better up high on the mountain but still the worst start to any year i have had here. Still only about 75mm ytd at my place and about 55mm ytd at work at Macedon. Yuk.

I'm starting to believe we might do ok this week. Finally some convergence in the forecast models. 30-50mm would be very welcome...

12.30pm mid level tropospheric water vapour image showing it is starting to come together.

Really hope it comes together. We need it! The models are still looking good, with EC looking the best for widespread rain in the latest run. No doubt there will be a few more ups and downs as we get closer to Wednesday, but so far so good. Some drizzle here this morning, but not quite enough to register in the gauge. Stayed mostly cloudy all day though, with a 15.5c maximum.

It's crazy how long it's been since I've seen the word 'rain' mentioned in forecasts.

The whole state needs this. I'm not even looking at the charts now, scared it'll just disappear again

Damp here for the few sprinkles over the weekend.
Few good drops.
Hope this comes along nice and slow.
Could do with one of these every week for a few months..
hope I eat my words,.

First look at the rainfall projection for one of the local higher resolution models Access R. This is for round 1 up until 4am Thursday morning. Access R is cutting off a 2nd surface low around Kangaroo Island on Wednesday night. A look at an even higher resolution model Access C tomorrow night will give a better mesoscale view of the potential.

AXS-R looks to be on the optimistic side. Both GFS and EC are suggesting 20-30mm, not 50mm for here.

Regardless, it's firming up to be the best rain since December.

As expected, plenty of uncertainty on the exact positions of multiple cut off lows. One common theme though is that there will be interacting jet streams ahead of the first trough on Wednesday into Thursday. Winds @ 700 hPA are being projected at around 50 to 60 knots into Wednesday evening to support the launch of multicell clusters from the north west. With plenty of mid level moisture, there could be some very big isolated totals that most models won't be currently picking up. In my opinion the only model with a high enough resolution to pick up this cell potential is Access C (4km res), all the rest are just synoptic scale mathematical darts at a board.

Looks like 3 to 5mm in Melbourne metro (2mm in West, 4mm in east over the course of 16 hours. Mt Dandenong will get 15mm, Mouny Macedon 1mm and CBD 3mm.

Now save this post and get back to me on Friday

Access C is actully 1.5km res so lots of storm blobs in there tomorrow some isol heavy falls for sure.

Sadly feel like it be an east of Swan hill to Colac system, with West Vic and E SA missing out but east of there widespread 20-40mm with isol 80 to 100mm in the NE rages

Fun few days get excited

Yes, spot on QT...I typed out the old spec for Access C. Strangely the BoM still reference 4km but it's definitely 1.5km res. http://www.bom.gov.au/australia/charts/ ... cess.shtml

UK, new GFS upgrading for this area 50 to 100mm, EC 40 to 80mm. Their projected NW flow means potential rainshadowing south of the range into Melbourne. Looking forward to seeing Access C tonight