Rain/Showers - Victoria: Saturday 23rd - Thursday 28th May 2009

The developing low moving up on Perth is expected be in the eastern bight towards the end of the weekend with some showers/rain likely to develop over the southeast. This system will be weakening, but will be drawing down substantial moisture. Both EC and NOGAPS show reasonable falls in Vic, while GASP and GFS have good falls to the west but not much for Vic.

With many places running near record lows for May we really need something from this one. Few days out but worth watching.

(Just edited the title and dates to incorporate showery weather today/tomorrow. Karl )

Yeah EC has been very consistent with this approaching weather event. I would still like to see GFS and some other models jump on board too, but there is still time for that. EC most certaintly shifts the wetter weather into Victoria on Saturday with a front, and continues to be quite persistent on Sunday and to a lesser extent Monday. As mentioned above, GFS keeps the rain areas west of Victoria with its own upper disturbance developing over South Australia on Sunday and increasing a fair bit on Monday, even reaching the western parts of Victoria with some patchy rain areas. After that its GFS that shows the better weather, with the disturbance shifting back over South Australia on Tuesday before finally getting a move on eastwards during Wednesday, slow-moving as well.

So plenty of uncertain weather features to watch, and fairly complex as well, but time will tell and I hope we get it.

Jake.

GASP and UK are now on board, though not showing a big system. Still the 5-15mm that these models are suggesting could double most of our monthly totals.

Few days out so plenty could change.

Next week is very messy in the progs - could be SW'ly or NE'ly depending on whether the shortwave to the south pushes through.

Is starting to look quite good this system now with NOGAPS, EC and UK all suggesting some reasonable falls - particularly west of Melbourne. Also potential for a few showery days in the south through next week in a cool SW flow. It's not going to be a drought breaker, but could provide some relief from this dry May.

I still think we are a few days away from anything concrete but the signs are there. I hope we can score in Melbourne too.

I'm not confident yet.

Yeah it actually looks good for up here for once which is almost a freak thing these days. LAPS looks like 15-20mm is on the cards for here and GFS around 5-10mm. Much higher falls to above 30mm progged over the western ranges and I guess if LAPS comes off falls of that magnitude possible here but more likely in the 10-15mm range I reckon. As Karl says you really can't be 100% convinced given our weather over the past 6 months with almost every promising system fizzing despite models being all over a rain event right up to the day but there is certainly something to go on with this one, Sunday might be interesting.

Yeah I'm not confidant either. The system to me looks to peak around the SA border before sliding SE even if it doesn't and peaks bit more further East since when do we get good rain in Central Victoria and Melbourne in strong Northerly winds? Rarely happens these days so at the moment I expect 1mm tops here. We need middle and low level moisture interacting with this system from the North and NE and at the moment I'm not sure where that will come from things in Western Qld and Central NSW are fairly dry all the activity is now on the coast but we wait and see again I guess. Western areas/Wimmera should fair okay this time round.

I don't expect much more than a few mm anywhere in Melbourne with the exception maybe of the Dandenongs, rain shadow will be a huge factor, but for my area in the west central ranges orographic uplift has a big effect with these weakening systems to the west as moist northerlies are forced to rise, similar in a way to how the Dandenongs and outer eastern suburbs of Melbourne can get big totals in SW airstream from relatively benign systems or setups, even close to a high centre at times. I reckon we're in for a shot up here and in western districts also.

Both EC and GFS are bringing through a decent rain event with this system and then put Vic into cool showery SW flow til mid week. The totals in western areas are solid - widespread 20mm+. There is a lot of moisture with this system and the upper trough is sharp with some good upslide. The models are tending to enhance this system as it gets closer which is a good sign.

Melbourne might not do so great - but then again Melbourne never does...

Most likely to see 2-5mm here so not getting excited.

Other areas will do well - up to 30mm over the Western
Ranges.

Yeah I agree with Karl at the moment would love to get a nice suprise but I still think the better falls be out west in saying that though EC almost cuts the system off in the trough over us now Monday but only model thats doing that

Sometimes these systems are the best for us, it doesnt look to organised, still decent upslide ahead of it but looks like it will slide down through western areas as per usual. Almost a case of forget about models and just take it hour by hour with this one.

Well, not really 'as usual' as we haven't seen even one of these systems so far this year and western VIC has missed out heaps, even more so west central, clearly on target for the driest first 5 months of the year here regardless of the upcoming rain event. Melbourne is set to miss out due to the rain shadow effect IMO rather than the system actually missing the Melbourne area to the west. It looks good for up here, 10-25mm now from GFS and similar from LAPS for my area, looks to be mostly Monday evening now.

System is looking very good for SE SA and western Vic. There is good upslide ahead of the low in north/northeast flow (despite the low weakening). The slow movement should see some good totals - possibly even some big falls (wouldn't rule out 50mm+ locally).

However, it weakens as it moves further west and the upslide collapses sometime on Monday/Tuesday. This should set up a sharp drop off in rainfall.

Central Vic is borderline for good falls - EC, NOGAPs and LAPS push good falls through central areas while GFS has it falling apart. Will be a frustrating day of watching the radar for those in central/west-central areas.

Hmmm. I'm sticking to 10-20mm over the western and Wimmera districts, a little less in the Mallee, but I think the northerlies will be way to strong for any substantial rain areas to move over central Vic, Melbourne in particular. There will be huge gaps in the band there which is not so good. On the plus side, as I said above, the western parts of the state should do well. I have hope for here, I'm confident in it for here, but not really anywhere else.

We need moisture pushed into the state ahead of it to get significant rain, and I mean a lot of moisture. Watch the models in NW Aus for the next week or so, we finally might see something good for everyone develop. Long way out, but the signs of a NW infeed are there.

Currently though, the winds are getting fairly strong here. CAn here them outside, but its freezing since I have been up in Cairns and I am not used to it.... lol.

What about Macedon ranges DJ. Countless times the ranges here produce rainfall in northerly flow at this time of year in a moist airstream even when the main system is to the west. GFS has over 10mm here, LAPS higher. I know I'm not going to get 25-50mm which I've writed off from the outset but even 10-25mm would be alright given the dire situation locally, it would at least slow down the damage to the environment here which is happening faster and faster as time goes by.

These endless flops shakes your faith in the ability of the atmosphere to produce rain, but give the current set up something like 20-50mm would have to be a chance up your way - perhaps enough to push you into the Decile 3 range for the month! There is a decent northerly jet associated with this system with a very sharp trough/ridge. These are usually very productive.

Am hoping/anticipating ~20mm in the Dandenongs which will put us marginally above the driest May on record (a sad state of affairs).

Interesting that EC, NOGAPS and LAPS have bumped up rainfall totals. I tend not to take too much notice of the details in GFS which goes for rather unrealistic rainfall gradients and very heavy falls alongside very light falls.

Hmm, I think it will be a bit more then that across western Victoria. Latest models are indicating up to 30mm in the southwest of the state, with 15-20mm over remaining Wimmera and Mallee regions, and I have heard EC is looking better then GFS, so things are looking good for the west of the state. I would not rule out any thunderstorm development either, particularly with any break in the clouds.

Currently, very windy northerly winds, touching gale force at times and most rain is still in the SA area, some light showers reaching the SW, mostly virga though.

Well, 20mm would be great although probably won't save us from the driest first 5 months of the year. We have plants dying here and it's almost winter, that's an absolute first.
I do notice rainfall totals are increasing in the model output but more importantly increasing further east also. Looks like a very solid and slow moving rain band with the blocking pattern actually working for us in this scenario. I guess I'll miss a lot of the rain being stuck in Melbourne all day, probably only light stuff near the CBD, 5-10mm possible but hopefully I'll come home to wet. Should still be plenty of rain about Monday evening I guess.

Still, can't get overconfident because we have seen these promising setups before this year right up to the day of the event and they have FIZZED! So all fingers crossed for this one it does look a lot more promising.

Just as a point of interest. 1991 was extremely dry here from February to May. Comparing it to the same period this year

1991 2009
Feb 4.0mm 4.6mm
Mar 26.3mm 41.5mm
Apr 38.7mm 41.1mm
May 26.6mm 5.1mm (so far but could end up around 25mm if this next system comes off)

So basically we should get over the Feb-May rainfall of 1991, all we need is a few mm here from this system. The big difference of course is Jan this year where we had an unprecedented 0.4mm for the month. In 1991 we had 79.5mm for January.

Even more interesting however is the total rainfall between November 1990 and May 1991 compared to the same period for 2008/2009.

Nov 1990/May 1991= 245.3mm
Nov 2008/May 2009(so far)= 294.1mm

So significantly wetter this time around and likely to get a bit wetter still before the end of the month. Interesting what you can find when you go through the historical records.

Latest LAPS is out and it is now spreading good falls right across the state. Western areas and right across the ranges will get the heaviest falls but southern and far eastern areas even look like 5-10mm is a good bet.

That's good news Thanks everyone for your wonderfully informative posts

Thanks mate.

Well most models have ramped up totals for this event now. GFS, LAPS, MLAPS and even EC still puting big falls over the southwest of the state, up to 75mm in some models, with more general falls around 20-30mm in the wimmera and mallee. The better news is, is that on Tuesday most models now indicate the rain band to move across all of Victoria instead of breaking it up as it previously done, and a general 5-10mm over central and eastern districts, locally higher. Isolated thunderstorms should be chucked into the mix as well, particularly the southwest tomorrow with a lot of divergence. Fingers crossed for everyone and it looks like we are moving into a wetter phase of weather at last.

Latest UKMet has 15-35mm in a wide area now for the West and the Wimmera which is a great sign cos Uk tends to be quite reliable also has some handy falls of 10mm arounf the Mallee 5-20mm for North Central & Northern Country, 5-10mm for Central areas and Melbourne then rainfall largely dissapates as it hits the East so not looking to good for Gippsland though the NE may do ok even if the system is dieing in these Moist Northerly set ups so even 10mm up there is possible.

Some fantastic falls clocking up quickly through the western districts (particularly areas east of about Edenhope) -essentially following the EC script which has the heaviest falls through from near Horsham to just east of Melbourne. In this band EC has widespread 20-40mm totals. Very impressive that this model has hardly budged on this system.

Top falls so far are Mt William 33.8mm, Dimbool 30.2mm, and Horsham 24.8mm.

Should be a nice wet day for many and I would imagine just in time for croppers - great to see. A very slow moving rain band so a few hours before it gets to Melbourne.

A few showery days to follow and getting quite cold with the odd snow flurry on the peaks (sure to bring out the ski industry spin ).

Currently very windy in the Dandenongs with blowing leaves from the European trees.

I'm a little apprehensive still with this strong N wind so some local topographic effects could mean we get little here.

Fabulous falls in the west with a couple of thunderstorms in the northwest with the rain.