Day to Day Sunday 10th - Friday 15th October 2021 Troughs and Fronts Eastern Seaboard

[AshestoAshes]

Hey Everyone,

I thought i'd put up a thread for this week's event. It's looking like a week-long event with a decent storm set up especially tomorrow.

Tomorrow will see the most activity for Sydney Siders the trough brings through a southerly which is likely to collide with this warm tropical airmass moving in.

The focus then moves north as a low moves in from the inland bringing rain and storms to Northern NSW and Southern Queensland. For my neck of the woods, tomorrow seems like one of the better storm set ups in past years.

 

[Perfect Storm]

Thanks for starting up a thread, AshestoAshes!

On brief glance - latest Access C (06z) appears to indicate rainfall of a convective nature across the basin.

Latest (06z) forecast accumulation chart till 11 pm tomorrow evening.

 

[Joshua Randazzo]

Thanks for starting up a thread, Ashes2Ashes!

On brief glance - latest Access C (06z) appears to indicate rainfall of a convective nature across the basin.

Latest (06z) forecast chart till 11 pm tomorrow evening.

i notice more rainfall out west and it slowly getting slightly lesser at coast

 

[Wavey]

Hey Everyone,

I thought i'd put up a thread for this week's event. It's looking like a week-long event with a decent storm set up especially tomorrow.

Tomorrow will see the most activity for Sydney Siders the trough brings through a southerly which is likely to collide with this warm tropical airmass moving in.

The focus then moves north as a low moves in from the inland bringing rain and storms to Northern NSW and Southern Queensland. For my neck of the woods, tomorrow seems like one of the better storm set ups in past years.

I'm honestly not seeing a whole lot of storm potential for Sydney at all. Lifted index is only around -1 for 10am tomorrow before getting back above zero later as that southerly stabilises the atmosphere. There's definitely been better storm set-ups in Sydney even in the last few weeks than what I'm seeing for tomorrow tbh. If anywhere in the Basin is to fire up into proper thunderstorm development, it'll be far NW Sydney IMO. But otherwise I reckon it'll be a Hunter and mid north coast special for tomorrow.
Thanks for the thread start too.

 

[Joshua Randazzo]

I'm honestly not seeing a whole lot of storm potential for Sydney at all. Lifted index is only around -1 for 10am tomorrow before getting back above zero later as that southerly stabilises the atmosphere. There's definitely been better storm set-ups in Sydney even in the last few weeks than what I'm seeing for tomorrow tbh. If anywhere in the Basin is to fire up into proper thunderstorm development, it'll be far NW Sydney IMO. But otherwise I reckon it'll be a Hunter and mid north coast special for tomorrow.
Thanks for the thread start too.

Im sure we will see at least something

 

[AshestoAshes]

I'm honestly not seeing a whole lot of storm potential for Sydney at all. Lifted index is only around -1 for 10am tomorrow before getting back above zero later as that southerly stabilises the atmosphere. There's definitely been better storm set-ups in Sydney even in the last few weeks than what I'm seeing for tomorrow tbh. If anywhere in the Basin is to fire up into proper thunderstorm development, it'll be far NW Sydney IMO. But otherwise I reckon it'll be a Hunter and mid north coast special for tomorrow.
Thanks for the thread start too.

Yh lol, i'm probs a bit excited with reopening and EC has biased me a bit. Hoping for a good dose of convection tomorrow to get the show on the road, if we get to about 26-28 degrees with sun we should have good time.

 

[Joshua Randazzo]

very strong storms just northwest of goulburn,possibly supercells?

 

[Joshua Randazzo]

just started to weaken off now but before they had a nice black core

 

[Wavey]

I reckon I could be wrong in my prediction last night. On paper it still doesn't look great for storm activity but the skies here are looking pretty interesting. Also I notice a few storms firing up down around Nowra with that southerly change.
And those storms last night too. That one that passed just north of Goulburn made it all the way to Huskisson and then out to sea.

 

[Joshua Randazzo]

nice little storms formed south of nowra

 

[Joshua Randazzo]

heating up nicely outside

 

[Billy Bob]

Fair chance of something later for Sydney if there's enough sun:

http://charts.bsch.com.au//tmp/gfs.stormcast.bsch.init-2021100918z.fcst-202110101300z.sweat.syd.null.0.png

SWEAT Index (Severe Weather Index) reasonably high.

 

[Donza]

Sunny to the west of Wollongong.

Can see some towers.

 

[Billy Bob]

I didn't even know there were storms about last night; it was clear here with just some wispy high cloud on sunset, certainly no sign of convection.

 

[Wavey]

Sunny to the west of Wollongong.

Can see some towers.

Starting to look pretty ripe and just hearing first rumble of thunder as I'm typing. It does look like a storm day. Some of them are forming right on the coastline which is pretty unusual. I see Hill 60 (Port Kembla) just got a brief cell.

 

[Jac0b]

It's now 27.6°C at Olympic Park and 27.4°C in Richmond and over 30°C at Gosford under humid E/NE winds. It feels very very muggy here in Western Sydney.

Hopefully the southerly triggers something.

 

[Wavey]

Pouring down here now and HUGE drops. Don't know how it's not hailing.

 

[Wavey]

Anddd it has stopped.

 

[Steve777]

Southerly has reached the Airport. It’s totally overcast here. While there’s a clearing edge near Penrith, the cloud is backbuilding over Sydney as it streams Eastwards.

EDIT: Storm cells are forming on the Illawarra coast and moving quickly out to sea.

 

[Donza]

Southerly has reached the Airport. It’s totally overcast here. While there’s a clearing edge near Penrith, the cloud is backbuilding over Sydney as it streams Eastwards.

EDIT: Storm cells are forming on the Illawarra coast and moving quickly out to sea.

Yup. They were popping up.

Sunny now and howling southerly.

 

[When I pour I reign]

The temp drop here in the Shire has been pretty dramatic in just this last 30 minutes. From muggy and humid to strong southerly wind cooling things off

 

[Homer]

Sun has just come out here now after a completely overcast morning.
Just as the southerly is about to arrive.
It made it to 31.7 at Richmond, so heating hasn't been a problem.

 

[Jimi]

Hard to feel like anything will happen now under this SE-ly.

 

[SnowBound]

Sunny Syd NBs atm. I’d say last bit of sun for a while.

Tbh I didn’t think it would be this sunny at 12:30pm based on forecasts.

 

[Homer]

Hard to feel like anything will happen now under this SE-ly.

I wouldn't lose hope yet @Jimi
I've seen plenty of storms over the years form after the arrival of a southerly.
In fact, one has just kicked off to the west of Nowra.
I still have my fingers crossed.

 

[Billy Bob]

Yes. The surface southerly is only part of the picture; temperatures remain warm for several hours just above the southerly (and just inland) and this allows storms to form and even intensify with a bit of moisture from the coastal change.

A classic warm wedge of 925/850 temps over the Blue Mountains and parts of the Southern Tablelands today which will support these storms if they form. That storm near Nowra is a classic example: it has exploded on the escarpment.

 

[Steve777]

There's quite a difference across the Sydney region. Just 19 degrees at the Airport under a gusty SE'er up to 31 degrees at Richmond under light Northerlies. The Southerly is taking its time working its way through. The Sun's come back out here.

It's 29-32 degrees in the Central Coast and Hunter and probably fairly sunny. A little envious.

 

[Wavey]

Yes. The surface southerly is only part of the picture; temperatures remain warm for several hours just above the southerly (and just inland) and this allows storms to form and even intensify with a bit of moisture from the coastal change.

A classic warm wedge of 925/850 temps over the Blue Mountains and parts of the Southern Tablelands today which will support these storms if they form. That storm near Nowra is a classic example: it has exploded on the escarpment.

A surface southerly with warm air above is generally not good news but the steering winds are that swift that it won't matter.

 

[Billy Bob]

Yes it can cap things in the absence of a trough but from experience the warm air above is beneficial along the trough line.

The Hunter had the highest storm indices on Stormcast, so yes should fire there later.

 

[Wavey]

Tbh I didn’t think it would be this sunny at 12:30pm based on forecasts.

Yeah me neither. Starting to cloud over a bit down this way now though. Including a big anvil moving over.

Edit can see why now, big cell over the SH. @Snowmaker7 ?

 

[Billy Bob]

A cloud fest here at the moment and the cool air has seemingly arrived earlier than forecast; a stiff easterly. ACCESS-C and Meteoblue etc. had warm air until late afternoon but EC's forecast seems to be correct.

 

[Homer]

Yeah me neither. Starting to cloud over a bit down this way now though. Including a big anvil moving over.

Edit can see why now, big cell over the SH. @Snowmaker7 ?

Scud or high cloud?

 

[AshestoAshes]

Line of precipitation forming to our west, sun's out temps rising again with a nice little kick to the dewpoint. Keen to see what's going to happen in the next hour. Although Meteye has got most storms arriving at about 8pm tonight so interesting times.

 

[Donza]

Dapto is about to get smashed.

 

[Perfect Storm]

Small shower popped up - cold drops from an otherwise clear sky. Looks like a decent cell popped up in the basin to the NW!

 

[Donza]

Southerly ripping the guts out of the storms as they get close to the coast.

 

[Snowmaker7]

Yeah me neither. Starting to cloud over a bit down this way now though. Including a big anvil moving over.

Edit can see why now, big cell over the SH. @Snowmaker7 ?

Heavy rain with huge rain drops and the odd pea sized hail. Looks like there's probably more to come, with that band from the west looking like it may develop into a line of storms

 

[Snowmaker7]

Pea soup fog now

 

[Perfect Storm]

Thunder being heard from the cell out towards Badgerys Creek - regular rumbles.

Very regular rumbles now and quite loud.

 

[Jac0b]

Yep I can lots of close rumbling from that one, and some lightning strikes as well.

 

[Long Road Home]

So what happend to southerly killing off storms? *rolling eyes*

 

[Homer]

These cells are exploding quickly.
I'm trying to get some invoicing done and keep getting distracted by checking back on the radar!
That Penrith one - whoa!

 

[AshestoAshes]

Black core dropped about 3kms west of me let's see what it brings as it moves over me, just some flangs and heavy rain so far. Nice little bonus before tonight's rain.

 

[Homer]

Black core dropped about 3kms west of me let's see what it brings as it moves over me, just some flangs and heavy rain so far. Nice little bonus before tonight's rain.

Development is explosive!
Also, the cloud mass following these storms has really grown in size in the past 24 hrs.

 

[AshestoAshes]

Let's see what that band of rain moving over Bathurst and Oberon brings, I'm thinking light rain but we never know .

 

[Edge72]

No warning from the BOM yet ?

 

[Homer]

So what happend to southerly killing off storms? *rolling eyes*

Yes, it's a common misconception that southerlies always kill storms. They don't always.
Let's hope that those that think this remember today.

 

[SnowBound]

Radar showing how quickly they're breaking up as they hit the coast. Southerly doing its thing IMO

 

[Homer]

No warning from the BOM yet ?

They're still looking out the window.

 

[Edge72]

Radar showing how quickly they're breaking up as they hit the coast. Southerly doing its thing IMO

It’s one is the gutsiest southerly i have experienced living on the coast for some years.