VIC: Low Pressure System (10/2-12/2 2012)

[Hamlan]

Great pics there Hamlan!

I especially like the first one, looks like it was taken on the Tullamarine Freeway (northbound lane) near the Western Ring Road interchange yes? Really nice storm structure there.

Was there much lightning (including CGs) around the time these pics were taken?

There wasnt a lot of visible lightning but the radio static was pretty busy. I did see one cg just after my pics were taken. And yes you picked the location correctly

[johnno]

Hamlan.. If you go back and read my earlier posts Today earlier this afternoon I said "Most of Melbourne will miss out" And thats exactly how it panned out. You don't have to tell me how Big Melbourne is we all know that Page 6 incase you have trouble finding it

[Jake Smethurst]

I would say today's event played right along the expectations. It was always scattered showers and thunderstorms, particularly near the troughs, and that's how it went. Whilst we didn't get anything here again, I'm happy with the forecasting that's been going on. Some big dumpers again today as many of you saw. I still can't get over the 223mm fall over the Otway's last night in about a three hour period!!

Nocturnal cooling could get a few cells going overnight, but probably will see some good areas of rain develop about the Otways again overnight and also in the east.

Some drizzly showers at the moment. Looks like it will set in overnight.

[crikey]

Having said we'd be extremely unlucky to miss out on rainfall, we missed out

HarleyB my thoughts exactly. We had visible storms,lightning and thunder to the west, east and north and looking at stormtracker south as well and yet we got nothing in terms of rain. a few spots. The big one from Maryborough area missed us
If you weren't under the storm you didn't get rain l assume. Here is a pic from mobile phone showing a storm cell developing over us and later let loose north of us around Serpentine
Notice how dry the paddock grass is!!

[rikjpool]

Headed south east once I finished work and went towards Sedgewick thinking I'd core punch and get to the other side. I got about 500meters into the rain curtain and was getting absolutely hammered by rain and marble sized hail. Turned around and headed back the way I came, thankfully as it decided to head NE and I was able to follow it for a couple of hours.
Screen shot of the intense rain curtain that I stupidly tried to punch


And some more from throughout the day in order of chasing. To tired to put together a report and do video now.... maybe over the weekend. Enjoy. I certainly did!


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Photo 1, 2 Sedgewick
3,4, Longlea Lane, Longlea
5 Barnadown
6 Corop
7 Colbinabbin

[Rhino]

To tired Rikki yeah right, more like to busy washing your jocks after that first screenshot I'd say.

Rhino.

[93ben]

I've been waiting for all day and still nothing! Is there any chance of a storm in Templestowe? There was a warning a while back but when I looked at the radar it looked like it was moving North West and not South West. They cancelled that warning just before it was expected to hit.It's a shame that it was going the opposite way. I'm really thirsty for a storm and there's like nothing, not even rain! Just clouds that aren't doing anything.

[droughtbreaker]

There will always be the places that get hit and the places that miss when you have a day like today. Romsey got 12mm, as far as I know we got absolutely nothing here (apart from a 30 second light shower late evening). Just the luck of the draw.

Tomorrow looks like a classic easterly dip (although a fairly weak one), with SE flow over the state, a bit of convergence around the low and moist and unstable. West central areas have the potential to do very well tomorrow with the kick off the bay. I would like to think my area is in line for 20-40mm although it has a lot to do with the trajectory over the bay and the orientation of the rain band. It will probably be more the Geelong to Ballan area that scores the best. Otways will get slammed yet again with 50-100mm a distinct possibility. Gippsland will get smashed 100mm+ in some parts over there.

Melbourne city and eastern suburbs probably won't do as well tomorrow. I'm thinking only around 5-10mm for those areas with 10-20mm on the ranges and hills. The SE flow will dump all the rain over South Gippsland and it will be drier on the other side. Northern and western VIC will generally be out of it as well relatively speaking. It is definitely looking more like a coastal and west central event to me.

[rikjpool]

Last one for the night

[crikey]

Just watched the last couple hours of radar frames and that right mover. Just sat there for ages, then decided alright, thats it, im leaving. Lightning seemed to die as soon as it moved too. Wonder what the mechanics are behind something like that...

Hi Meso. One day l was watching a mesocyclone storm up in north central Queensland on national radar a few weeks ago and l had taken some snaps and marked the direction of cloud movement and noticed that this MESO had developed in the area of divergence where the cloud was splitting into two different directions

I have learnt that when an air mass diverges it creates a localized area of low pressure where the surrounding air in fills and probably creates quite an updraft
Hence a severe storm cell( of course dependent on the other factors for storm development)
of course you know this is not the only way severe storms are formed

This storm created a hook echo and winds of 173 km/hr at the surface

Now the Lang lang/pakenham storm yesterday had the same divergence pattern
See page 3 of this thread where l posted the cloud direction you can see the storm sat in the area of cloud divergence
with hook echo signature

Now as to why the storm was a right mover. I would suggest that the cloud flow and air stream flowing N/west to s/east was stronger and the storm was steered or dragged into this flow

I would imagine that is why you get storms spitting as they are in an area of divergence where on half goes left and the other goes right so to speak
Check it out yourself in the future and test this observation
Here is a diagram of the cloud flow and divergent area with the storm forming in the fork

As for the declining lightning, l would suggest that once the storm was pulled away from the fork it lost the added uplift from the low pressure area at the fork of the divergence, reducing the powerful convective forcing

[Hamlan]

Hamlan.. If you go back and read my earlier posts Today earlier this afternoon I said "Most of Melbourne will miss out" And thats exactly how it panned out. You don't have to tell me how Big Melbourne is we all know that Page 6 incase you have trouble finding it

Johnno no need for the defensive reply. Your post said what it said. Why should anyone have to to refer to previous posts for context when you make a clear statement like yours. You've now clarified what you meant so thats great. I've never said anything before to the usual (not including you) whingefest that usually follows an isolated Melbourne event like today, but I, like a lot of others (perhaps you too) am sick of reading it.

[crikey]

That's a sensational set of photos RIKKI!! You must be very pleased with your chase efforts. WOW and WOW
Hows all that green color in your last photo for the night within that shelf cloud. Looks like a signature for possible tornadic development? EERIE!
You certainly did some miles today.
Great mammatus cloud pic as well!

[Supercellimpact]

Picked up about 6mm from a dieing storm, at least it's something. Not expecting anything much tommorrow as it will be focused around the coastal region. They should do very well and maybe some localized flooding.

[Skywalker]

Good morning all

The drought has broken here and have finally received some decent rain, over 20mm so far in the gauge. So glad I've been proven wrong. Still falling here so 30mm is not out of the question.

[nafets]

Just checked last nights radar archive and it seems most of the showers were east and west of here. I will check how much rain in a minute.

[johnno]

7mm here. The heavier stuff went just West and North of me towards Melbourne Airport (20mm) & Essendon Airport (18mm)

[Mikew]

surprised to see 8mm here in rain guage this morning
plenty more to come by the looks of it in Bass Straight

[Australis(Shell3155)]

Gorgeous Rainbow to the west just now..

[nafets]

7.5 mm overnight. Doesn't look like much for a while, there's no showers south of me over the bay..

[Duckey]

Heavy shower going over at the moment and it feels very wintery today! Humid air is gone replaced by very bracing southerlies.