Cold Outbreak - April 23rd - 29th 2012

[Karl Lijnders]

A substantial weather event looks likely to unfold across Victoria in the coming week with an active cold front and cold pool developing in the region bringing snow levels down to 1000m and widespread showers, hail and thunderstorms to much of the state.

Some models clear the weather quicker than others, but overall it is going to be a wet week with widespread 20-50mm for the south and 10-25mm over the north.

Sunday there will be patchy rain, more extensive over the northeast and southwest but lighter falls elsewhere and remaining fairly mild.

Monday scattered showers and isolated thunderstorms will develop as another cold front slides over southern Victoria during the day shifting winds colder westerly later. Mild ahead of the change in the east and north.

Tuesday the showers will begin to increase over the state and tend to rain over the rangs during the day. Local thunderstorms with hail and snow developing at 1000m. Squally SW winds developing in the far west extending slowly east during the afternoon to reach central areas overnight.

Wednesday there will be areas of rain and local thunder over south central and west gippsland, with widespread showers over remaining western districts. Local thunderstorms with hail extending to the east by afternoon and snow developing down to 900m. Squally SW winds extending throughout. Cold.

Thursday, widespread showers, scattered hail and thunder over southern areas of the state but becoming more isolated over the north during the day. Rain over the NE. Snowfalls down to 800m at first lifting later in the day to above 1000m. Squally SW winds beginning to ease over the west of the state.

[stevco123]

Hardly a "cold outbreak" if you go by the bom's forecasts (18, 19 on each day). The models are slightly more promising though. I'm a little sceptical at this stage but here's hoping.

[droughtbreaker]

It's a cold outbreak in the models. What's the bet BOM will revise those temps down in future forecasts? It's a pretty common occurrence for BOM to do that. BOM like to sit on the fence when models aren't all lining up 100% and that's good policy IMO, it does mean however that the mid range forecasts are going to be out every now and then.

IMO, Karl's analysis of the situation is a pretty good one, although most areas of the state won't see it as active for as long. Still 10-20mm in it for large parts of southern VIC but the 25-50mm falls will be mainly in South Gippsland and the Yarra Ranges, outer eastern Melbourne and coastal.

Snow down to 800m seems about right to me, especially Tuesday/Wednesday.

[johnno]

Wouldn't suprise me to see temps of only 13-15c on Tuesday across Melbourne 16c seems abit high at the moment with the cold air heavy cloud cover and rainfall

[droughtbreaker]

OCF has 14C in Melbourne on Tuesday, also 25mm of rain Monday/Tuesday. The Tuesday forecast maximum for Kilmore Gap AWS, also from OCF, is just 8C.

BOM still sitting on the fence.

[stratospear]

BOM shouldn't be sitting on the fence now that all the models basically have consensus of a significant cold outbreak on Tuesday. Even Access-R is going for 500HPa temps down around -29 degC. Perhaps they're factoring in the CBD heat island...

[blackmamba]

Does the thunderstorm map at the bottom of the page mean we may be in with a mild chance?

[Karl Lijnders]

Fairly clear this morning, but can see the high cloud of the storms and showers to the west. Latest models really want to crank this system up for C areas and that should start from later today. Showers increasing with local hail and thunderstorms looks fair.

Could be very wet tomorrow with 30-50mm likely now in this rain event. That should break to showers during Wednesday but still fairly wet for ANZAC day and then a slow clearance.

Looking much colder but still strangely humid this morning!!

Still on track from last week.

[Rhino]

Had 2mm here this morning and still raining lightly. Not expecting alot over the next couple of days even though rain is forecast tommorow, may squeeze out 10mm but even that would be good considering how dry it's been. As Karl said central and SW areas will do well.

Rhino.

[I_Love_Storms]

Cold air alert

Cold air currently interacting with rainbands NW of Melbourne leading to intensification of rainbands and moderate falls. Showers/rainbands expected to explode over eastern suburbs over coming hours.

[Karl Lijnders]

Yes quite right there ILS. I think showers even spreading to areas of rain over parts of C VIC over the coming few hours. Local thunderstorms towards the east of the state and developing in the SW this afternoon.

Otherwise all eyes on the low pressure system this afternoon and to see where it winds up.

[Rhino]

9mm here now this morning so more than I thought for today here, not complaining though. This arvo looks interesting

Rhino.

[Karl Lijnders]

Should get around 25-30mm up there Rhino. So plenty more to come.

Showers starting to get a thundery signature to them now too across C Victoria. Hard to say what level of storm activity about today, but I think it will be more embedded in amongst the rainfall here in Melbourne but become more scattered along the coast tonight as the cold air works closer. Watch out in the east for severe thunderstorms today.

Melbourne could walk away with 10-25mm today as well. A wet afternoon on the way.

[I_Love_Storms]

Looking good. Very unstable and lots of scattered, embedded thunderstorms. Some areas are going to get an inch today. Expect it to get quite nasty around peak heating.

Bit of lightning on the tracker. Quite a lot down past Geelong some up between Ballarat and Bendigo.

http://www.weatherzone.com.au/radar/vic" onclick="window.open(this.href);return false;

[rikjpool]

Couple of iPhone pics....
Nice core south of goornong that I had to punch while working... Haha.


about to head into the core


And an isolated cell that wrapped up nicely for me before it flattened out...

[James]

just a tip, it would be good when a new thread is started if you can say so and close the old thread, i have missed all these posts as i wasnt aware a new thread had been started, i dont always go to the main page, rather referesh to see new posts and wondered many a time why so little talk, only to realise a new thread has been going some time

[Karl Lijnders]

Just had 13mm in the last hour at home and next to nothing 5km further west at work. So some big falls about.

Getting active to the NW and another very heavy burst across the entire city is likely as we go into WNW winds this afternoon and into tonight.

[mad*moo73]

A few rumbles here too!

[I_Love_Storms]

Just got caned by a hail storm in Camberwell. Pea sized hail

[StormSurge]

Just got hammered by hail and very heavy rain. The thunder was constant too, every couple of seconds.