Victoria: Cold Outbreak/Low Pressure. January 17-20 2010

[tizza]

I'm fluctuating from clear skies to showers norfolk, just had a light one pass over and now it's clear again.

[droughtbreaker]

Sunny here atm but lots of convection starting up now to the west and SW and it looks much more promising than yesterday. Still missing out to the west though. A decent shower on radar over the Wombat forest that I can see from here but just have to watch as it rolls past.

[norfolk]

so its gonna be a hit and miss day by the looks of it, u either get everything or nothing!

[Blackee]

In regards to this mircoburst down at Edithvale, the following radar sequence is between 12.30am and 1.30am.

Reports that the microburst was around 1am or 1300 UTC. The poor quality of the airport radar hinders the review.

http://radar.strikeone.net.au/?fuseacti ... 1263738600

[johnno]

That blob of cloud on the Western side of Tasmania on the Western side of the upper low may affect us later today or tonight and perhaps increase shower activity for a period.

I'm guessing the Melb catchments have done well 20-40mm so far?

I expect very little here during the day activity may increase tonight due to the fact that Cold air Showers are attracted to land during the day and the bay at night (wherever its warmer) so given now we are in a SSW airstream I expect little in the Inner Melb area during the day and more shower activity outer West of Melbourne, East and parts of the Northern suburbs.

[Blackee]

What total are you up to Johnno? I just noticed Essendon Air has received 7mm since 9am.
Just spoke to the leader of the opposition and we have 28mm at home.

[Instability]

I saw the flash through closed eyes, but thought I must have been dreaming and didn't bother to 'count', but my BIL and SIL report their kids being woken by a 'massive thunderbolt' at the same time, and they are in Blackburn South! It certainly wasn't overhead me, that's for sure, but was nice all the same!

A colleague who lives in Scoresby said the same thing. The rain woke him up earlier and he was lying there with his eyes closed and still saw the flash. He said he got to about the "th" in "two-one-thousand" when the large crashing thunder sound came. Sort of makes you wonder what made this one bigger and louder then most

Rog.

[johnno]

3mm here Wes with this system that heavier stuff that got Essendon airport just missed me to the NW earlier on

[Blackee]

Fire Weather Briefing for Victoria
Issued at 11:00 am EDT on Monday 18 January 2010.

Estimates Today:
The estimates today look reasonable. Strong and gusty southwesterly winds will
continue with cooler than normal temperatures. Although the "airmass" is dry,
extensive convective shower activity will be found from Melbourne eastward
along the coast and into the ranges of both west and east Gippsland. Some of
the convective shower cells may develop into thunderstorms about the coast and
a little inland from the coast in particular, with small hail. In the eastern
ranges, cold air aloft will support snow or a mix of rain and snow at
elevations above 1500 m. A general 10 to 20 mm of rain is possible over
southeast Victoria where most of the shower activity is anticipated today.
Elsewhere, a general drying trend is expected with a good bit of sun north of
the ranges, especially northwest Victoria where skies will be mostly sunny.

Observational Network Status:
The AWS at Mount Baw Baw is not reporting and Hogan Island is still missing
wind direction.

Weather Situation:
A low pressure system will form to the southeast of Victoria today whilst a
high pressure is over the Bight. The high pressure system will weaken as it
moves towards Victoria on Tuesday and then move to the Tasman Sea on Wednesday
and Thursday. A trough of low pressure will develop in the west on Thursday and
a cold front will approach from the southwest later in the day.

24 Hour Rainfall to 9am:
Shower activity was mainly confined to areas south of the ranges with parts of
the central district east of Melbourne receiving a good wetting with upwards of
30 to 35 mm. There was an isolated higher amount of 39 mm at Warburton. In West
Gippsland amounts averaged closer to 10 mm and 1-5mm in East Gippsland.
Elsewhere amounts were not quite as generous with 5 mm or less West of
Melbourne, and little or no rain catch north of the ranges.

Weather Today:
Scattered showers mainly on and south of the ranges, falling as snow on the
Alpine peaks at night. Cool with fresh southwesterly winds, strong at times
near the coast.

[johnno]

Nice drop so far Warrburton way there Wes.. Imagine if the Cut off low and wrap around bands had of come off like EC had it earlier on boy these areas would of got 200mm+ thanks to the very warm bay

[Blackee]

Yeah mate, some amazing numbers dotted around the place. The one that surprises me is Rog (Instability) with only 9mm. Burwood is normally wetter than most places.

Just receving a sun shower in CBD at the moment. Temps also up to, 17.5c.

[Australis(Shell3155)]

Another small Hail storm here 11.53am.
30.5mm for the system.

[Sean Mac]

Heaviest shower/squall of the day just passing through now.
Edging to high 30's and counting.

Decent hail a little earlier but was shortlived. No hail with this one.

[Petros]

Only infrequent showers to report here from last night/today, totalling 5.5mm. 17C atm (been down to 10C). Baro up two to 1088 hPa since last night. We've had only infrequent SW wind flurries in last 12 hrs, certainly not windy.

No thunder to report, but the 6/8 cloud streaming in here from the SW has several dark-bellied Cj's around. So a storm is certainly not out of the question.

[norfolk]

haha I totally forgot there were showers about! Interesting thing about the weather, today should be a typical below 20 degree day, however I am just keeping an eye out to see if it gets above 20!

oh and still nothing more than 2mm at most here

[Blackee]

Petros, latest BOM storm chart puts coastal areas east of Melbourne as "likely" for storms.
I would add the map, however I am having troubles with photobucket.

THUNDERSTORM FORECAST

Issued at 11:55 am Monday, 18 January 2010,
Valid until midnight on Monday, 18 January 2010.

As an upper trough passes over the eastern part of Victoria the associated
instability will provide the potential for isolated thunderstorm activity over
central and eastern Victoria. A low pressure system that will form near eastern
Bass Strait overnight will sweep a trough over Gippsland. Thunderstorm activity
will be more likely with this trough over Gippsland and Alpine areas. NOTE:
Localised damaging winds are possible with thunderstorm activity about the
Gippsland coastal plains.

[Karl Lijnders]

Sitting on 41mm here for the event so far with another huge deluge of rain and hail. Rain drops were the size of 50c pieces and the rain roar was evident 2 minutes before the first drop hit so that was HP shower. Winds to about 30 knots as well briefly.

Can see further convection to the south and west, showers are beginning to slow down a bit so we could see less showers, but equally high totals as they are slower to move off. Brief easing over east Melbourne this afternoon before focus shifts back.

Cannot see it turning southerly either, should shift back to the eastern suburbs as a surface low forms and deepens further east causing further showers out here.

[droughtbreaker]

Finally got a half decent shower, but still ridiculously brief. Might be lucky to get another 0.5mm from that. General look of the sky and radar is promising though and we are only 12:30pm so you would expect showers to increase even further as the afternoon continues.

[Karl Lijnders]

Amazing how the stream just east of Scoresby starting from Rowville through to Lilydale always works in these setups. Localised heavier falls through here east of Scoresby AWS and further northeast of here through Boronia to Croydon to Lilydale.

7.8mm since 9am
33.6mm to 9am.

I have had 4 direct hits from storms here in the past 12 hours. And 8 hail showers. Biggest hail was 1.5cm - 2cm @ 2:25am. Strongest winds were 93kmh yesterday @ 1:25pm.

Had it all!! This time last week was 42C!

[norfolk]

tale of two cities I think is quite appropriate today, 1. Those of us starving for some rain, 2. Those of YOU! getting your fair amount.

Goes to show how how we were all correct, those of you who forecast good rain are probably getting it, those of us who forcast just dry and windy conditions are also getting it!