Victoria: Low & Cold Front - 20-24 November 2018

[snowfall]

Warm one today - 28c max here. The wind this morning has dropped back, and it’s feeling quite summery. I see the BOM have reduced the forecast rainfall slightly in central areas, but if storms develop and become severe then some areas could well achieve some higher totals. Interesting week ahead, basically going from summer to winter in a few days!

[JasmineStorm]

@ Wilko, yes...the BoM have to be cautious as projections are changing every 12 hours (like they always do on these beasts). The BoM's 4.20pm forecast is mostly put together from the 12Z runs from this morning. Since then, GFS has upgraded in certain areas. Access C is sitting on the fence, EC still going big on the east side of Melbourne....etc. For me, the great unknown is how much the warmer than normal Tasman cranks up the moisture advection machine. In the right position, the surface low will draw on sea surface moisture that is currently between 18 to 22c. This could go big very quickly in central or in west Gippsland. That's why I like to look at observations as we near kick off

While we wait, here is an interesting historical view of the 1934 event weekly total against the latest EC run 00Z today over the next week or so which could have a follow up low. As HB mentioned yesterday, if the low cuts off in the right spot….

[hillybilly]

26C here in FC today, so definitely warm for November. Guess that translates to about 32 or 33C at sea level. Our solar heated pool is now up to 27C so getting a work out by the kids

Progs not really budging now. Firmly showing 50-100mm. Gfs which was tending to be a little lower has come back, and now has widespread heavy falls on the V2 and V3 model.

The detail will matter a lot here. There will likely be a number of mesoscale lows develop in the broader low complex. These will focus the rain for periods of 6-12 hours. The 1934 event had such a low just near the South Gippsland which put Melbourne and the Yarra Valley in the firing line. Atm this event looks to me like a 100mm type event here, which would be about a once every six to twelve months event for us (which would be very welcome). Last year we saw 170mm from the December low so that’s the recent high bench mark for us. Would love one of those, as they put the fire season on hold for a month or two

Tomorrow looks good for wet slow storms in central areas. Gfs in particular is going off with heavy falls. LI drop to around -3 so plenty of instability. It should form a decent band moving west to east so expect to be shared around for areas east of about Colac.

[StratoBendigo]

Fun times for Southern and Eastern Vic. A nothing system here. We will be lucky to see 15mm now.

[Hawker]

Yeah Strato depends on whether we can crack it for a storm or not.
These systems often develop the storms to the east/south east of us here, then go down and pummel Melbourne.
We might crack it for a random rain band at some stage, otherwise I am going to go for another 8mm to
go with the last 2 falls of 8. Probably going to spend a lot of time waiting/watching for not much result.


Er edit but I will be very happy to be wrong!

[Sean]

The BOM's Hobart forecast puts Melbourne's to shame!

[hillybilly]

System looks to be on track. Very warm night, with a current temperature of 25C in Melbourne Trough sits in western Victoria and is slow moving, expected to move through central areas late arvo. There is a decent shot of low level moisture racing south through NSW with dew point jumping from around 5C to near 15C. By early arvo dew points ahead of the trough will be widely into the teens, and instability indices showing significant instability. The LI will be widely in the -3 to -5 range, so lots of potential. Low level shear is significant with northeasterly winds near the surface, becoming northwesterly aloft. This will help with storm structure. Overall winds are fairly modest, so storms will not move too quickly.

Expecting the radar and lighting tracker to light up from about 2 to 3pm, with lots of storms through central areas around rush hour

Wednesday looks like a bit of an inbetween day as the main low moves into western areas, then a secondary system develops near Bass Strait and becomes dominant. Heavy showers and rain becoming widespread Thursday and Friday, with most models showing falls in the 50-100mm range for southern and mountain areas east of about Geelong. Looks like a 100mm system here, based on current guidance.

[Didjman]

Expecting the radar and lighting tracker to light up from about 2 to 3pm, with lots of storms through central areas around rush hour

Thats good Started work early today to finish at 3pm! Cams and sound recorders checked!

[StratoBendigo]

As of today I will no longer believe what any numerical model says we might get. Stupid divergence just hours out. Everything from 5mm to 50mm on offer.

May as well throw dice in the air to predict it.

[JasmineStorm]

Good morning everyone, might be some weather around today

Atmospheric river now running at about 40mm across all layers of the troposphere on the S.A border. Large moisture plumes bubbling on the water vapours images in the same region.

GFS 18Z has just detected a ‘negatively tilted trough’ set up from the Mallee to about Geelong this afternoon. Haven’t seen one of those for quite a while, generally it means KABOOM with a Jet powered scenario, warm and cool airmass advecting at different levels allowing instability to go through the roof. Looks like a set up for high precipitation multicellular clusters to me. Probably 30 to 50mm + if you get under one

[Wilko]

Awesome guys
Gutters cleaned and repaired

[Adam38]

I’m in for a bit of a shock when I disembark the plane at Avalon airport on Friday

[StratoBendigo]

Good morning everyone, might be some weather around today

Atmospheric river now running at about 40mm across all layers of the troposphere on the S.A border. Large moisture plumes bubbling on the water vapours images in the same region.

GFS 18Z has just detected a ‘negatively tilted trough’ set up from the Mallee to about Geelong this afternoon. Haven’t seen one of those for quite a while, generally it means KABOOM with a Jet powered scenario, warm and cool airmass advecting at different levels allowing instability to go through the roof. Looks like a set up for high precipitation multicellular clusters to me. Probably 30 to 50mm + if you get under one

18Z GFS has thrown any sense of reality out the window. 95mm here - yeah right, it's gone tropo.

[tonycynic]

Nice compact band going through SA at the moment. Looking forward to seeing the same here this afternoon.

[JasmineStorm]

Access C 18Z run is picking up the same angled 'negatively tilted trough' but little more east than GFS. This late pick up must be because of a slight change in the jet stream. Hmmm.... I'm going to be watching doppler radar very closely this afternoon for signs of rotation and rogue right hander mesocyclones.

[Skywalker]

Well I've done everything in my power to ensure that we end up with a fizzer here in the western desert.

Lawns mowed - check
Gutters cleaned - check
Old plants removed - check
New plants in the ground - check
Mulch in place - check
Phones charged - check
Rain gauge emptied - Forgot!!

So lets now sit back & see what actually unfolds.

[Blackie]

Well I've done everything in my power to ensure that we end up with a fizzer here in the western desert.

Lawns mowed - check
Gutters cleaned - check
Old plants removed - check
New plants in the ground - check
Mulch in place - check
Phones charged - check
Rain gauge emptied - Forgot!!

So lets now sit back & see what actually unfolds.

Exactly. Let's not kill it before it starts again. Great reporting thanks JS and HB. Looks likes things have stared to fire up in the west of the state. Excited about the next few days and may do a snow chase on Friday

[hillybilly]

Lots of sparks showing up in the radar hole in the Wimmera. This is exactly where the models picked the development to start, then sweep southeast. Was expecting a bit more clear air today, but doesn't really matter as the atmosphere is destablising nicely as warm moist air comes in from the northeast and cooler air advects in aloft. You can see the two parts to the rain event today, with the storms initially, followed by the rainband which sits back near the SA/Vic border.

DPs rising nicely overall, with Melbourne going from ~5C earlier to ~12C now.

[Horts]

Thunder at work in Mount Waverley

[phunkster]

Thunder at work in Mount Waverley

Heard that one at work in Notting Hill, radar filling in nicely and things are kicking off nicely to the NW