Australian Severe Weather Forum

Quite a nice line of storms has developed through NSW with a BoM warning for flash flooding and damaging winds from some of those cells.

Meanwhile a lot of rain is spreading into northern NSW from the tropical low over QLD. Isolated falls over 200mm have already occurred in some parts of the QLD Central West district. Yesterday that system managed to intensify near Charters Towers with winds reaching the equivalent of a category 1 tropical cyclone. The satpic signature was quite impressive at the time too.

These were the two warnings the QLD BoM issued prior to the system weakening towards evening.


TOP PRIORITY FOR IMMEDIATE BROADCAST
SEVERE WEATHER WARNING
for Hazardous Winds and Flash Flooding.
For people in Herbert and Lower Burdekin District, the Northern Goldfields and
Upper Flinders.
Issued at 12:10 pm on Tuesday 15 January 2008

Synoptic Situation: A 995hPa low is located near Mingela on the Flinders Highway
between Townsville and Charters Towers and moving towards the southwest. Despite
being overland the system has intensified and may affect Charters Towers later
this afternoon.

Expect heavy rainfall near the low particularly on the western and southern
sides. Winds strong enough to bring down trees have been reported near the low
from a number of locations.


TOP PRIORITY FOR IMMEDIATE BROADCAST
SEVERE WEATHER WARNING
for Destructive Winds and Flash Flooding.
For people in the southern Herbert and Lower Burdekin district, the Northern
Goldfields and Upper Flinders district east of Pentland, and the Central
Highlands and Coalfields district north of Moranbah.
Issued at 3:55 pm on Tuesday 15 January 2008

Synoptic Situation: A 990 hPa low is located about 10km east of Charters Towers
and is moving south southwest at 20 km/h.

Expect very heavy rainfall and localised flash flooding near the low
particularly on the western and southern sides. Destructive winds gusts to 125
km/h are also possible near the low. Charters Towers Airport reported sustained
winds to 96km/h at 3pm.

At the moment there's a very long lines of sustained storm action - probably why the forum is quiet no doubt, everyone is out!  WZ lightning tracker showing plenty of it toward lower NSW towards Sydney.  Looking forward to any reports and photos.  A nicely spiralled low in the image MB, has got some intense signs in it.

Mike

Nice storm moving through Sydney at the moment - tracking generally north through thew western suburbs. Nice radar signature, in fact I would not be surprised if this is a sluggish supercell -- seems to be a persistent updraft and I assume it has generated some enhanced SRH by tracking north. Also this has probably developed on a nice boundary with the winds having just switched to southerly here (at North Ryde) Jimmy reported hail near Schofields although the current BoM warning does not reflect this as yet (rain, wind warning atm).

I am too busy to chase these days sadly, well atm anyway, as this would have been a good one to get onto earlier form here at Nth Ryde (ie M2). Took a few mobile phone pics from the building.

Coming down from Castle Hill to Parramatta about an hour ago it was very black, with lots of CGs off to the SW. Not being sure which way things were going I came home to get the car under cover and check out the situation as I hadn't been online all day. I see the storm is tracking north. At home there has been lots of rumbling, but mostly IC strikes. I see just now on the radar two more storms have formed with the current one west of Hornsby heading due north and looking like it might run into a heavy one that has just developed NE of Richmond.

Looking at the radar any more action here will depend on what the current ones forming around Taralga end up doing.

Sydney Storms, 16th Jan 2008

Hi Gang,
               another great chase day for me, whilst trying to get work done at the same time.
  By 1pm I was finishing a job in the Milperra area and was alreading photoing several large
cells over the mountains and another quickly growing one to the south of the city. Had a
workmate with me for the day, a new addition to the Sydney branch, having just arrived from
Auckland, NZ.    I was laughing as he struggled with the 37deg temps, not what he had ever
felt before.
    Coming out of the shopping centre at Mt Druitt (my last job) I was greeted by a huge cell
going up to the south.  Watching this thing blossom was amazing.  I headed south via Roper
and Mamre Rds, then via M7 down to Ingleburn where I got underneath it.
   On the way down the M7  I videoed many CG's  and more of them from Ingleburn.

  I sat in this area for some time and watched many good CG's some close some not so.
letting the cell pass over me to the nth, I quietly followed it back north up the M7 to the M4 Jnct.
It dropped plent of heavy rain,  but I didnt see any hail.

Dave N

Storm 16 January 2008

Hello, I was tracking this storm a little around 3.40 pm to 5 pm. It seems to develop around Camden, tracked north and weakened north west / north of Blacktown / Castle Hill. The storm did produce a barrage of cloud to ground lightning strikes and I read or heard reports of:-

- Rainfall of around 28 mm in 20 minutes in a suburb north of Camden.
- 50 sets of traffic lights blacked out in western Sydney.
- No less than 4 car accidents on the M4 in peak hour caused by the weather.

At Auburn there was a light shower and rumblings of thunder. The storm passed to the west but the core appears to have passed over or close to Blacktown again.

At lunchtime 1 pm, I had a look at some storm activity across NSW and there were two bands of storms crossing NSW at this time producing some 138 lightning flashes per minute (2,063 flashes in the 15 minutes from 1 pm to 1.15 pm (GPATS)). Several strong cells were located inland from the south coast (West of Narooma) and another band NW of Sydney. Both clusters were active.

I watched a small intense cell develop on radar west of Wollongong between 1 pm and 1.30 pm but it remained over rural areas.

Harley Pearman

Report January 16th 2008  Western Sydney severe storm and hail chase

I had not real intentions to chase today given the weak wind shear and being just plain lazy. It had to happen in the Sydney region unless I saw substantial development elsewhere. There was none really the dramatic elsewhere although radar did show some intense cells in "no-man's" land further south. Did anyone get onto those?

Whilst I was about work at home given the anvils had cooled the air a little, I noted a nice cumulus developing to the south. It looked interesting at least as it had gone up over the basin and had developed pileus.

When I looked once more, several convective towers were rising rapidly - this cell had almost exploded to some extent and was continually developing more updrafts. Within 3 minutes or so, I had grabbed the gear and was out the door! I stopped across the road to photograph given the uninterrupted views of the updrafts.



Then I headed to Prospect for a much better vantage point and contrast knowing the storm was going to track north along the boundary. Even as I had entered the area, the storm was producing frequent lightning activity from the anvil and into the core or near core region. Towers were rapidly developing overhead so I had to be careful of impending lightning bolts. The base structure took on a near circular base structure although relatively high based. Nevertheless, the structure and contrast was quite impressive and the lightning, incredible. My vantage point was littered with factory units but at least better than nothing.





Finally, the rain free base began to dump - it was time for a core punch. Hitting the M4 bound for Rooty Hill, it was slow but at least moving along. Turning onto the Wallgrove Road, I was mostly within the impending core at this stage. The winds strengthened and rain got heavier. As the lights turned green it began to hail to approximately pea sized. The hail persisted until the Rooty Hill itself. It was not until I crossed the overhead bridge at Doonside that I was back suddenly in a hail core and the hail falling prefusely. Water covered the road in torrents in this area but I was able to progress north. It was near the Richmond Road intersection that thngs got hairy! Hail to at least 1.5cm perhaps up to 2cm ripped down with a localised microburst or downburst! It was an impressive sight as leaves were stripped off the trees - cars and their drivers trying to huddle under any form of proectection - images of the Western Sydney hailstorm came to mind! The hail remained for a few minutes but tapered off. As I approached Schofields, only very heavy rain perhaps a couple of stones of hail fell. Nearing Windsor Road, it was clear the storm was north west of my location. Based on the structure I did not continue to chase. My decision was confirmed as the storm had weakened somewhat - perhaps crossing any boundary it had relied upon.

All in all, an interesting afternoon and hailstones thrown in once again twice in a week! And within the Sydney metropolitan area.

Regards,

Jimmy Deguara

G'day Jimmy,

We probably passed each other as I was in the same area around Doonside during the downburst. I watched it from Blacktown Hospital and then headed off after being given permission to chase by my wife and two day old son! I bit of fun but a little hair rasing at times seeing large gum trees  nearly snapping in the downburst.

Btw, My new son is doing well, Kim had him on monday at 6pm.

Also Jimmy your first image kind of reminds me of this cell which also occured along a southerly change.


Jeff.

Chase Report for today at Sydney Storm Chasers



Congrats on the newborn Jeff. My wife had our first 7 weeks back. Still waiting to get him out on his first chase!

Feel free to continue congratulations in a new thread as well as updates in the social area of the forum.

Weather Report Narrabri, NSW, 16th Jan.

We did well for rainfall although I don't think there was any lightning nearby. One of our weather stations recorded 57mm in 1 hour between 11am-12pm and finished up with 74.6mm at 9am this morning. A bloke from Maules Ck SE of Narrabri emailed us to report 125mm had fallen to 7pm last night! Our other local weather stations recorded 13-25mm to 9am this morning.

Weather Report, Lightning Ridge, NSW, 16-17th Jan. 2008

Hi guys,
What a nice looking rain system situated over inland QLD. We are only just catching the southern edge here at the Ridge, receiving 9mm in total yesterday (the 16th) from 7:30am until 11:00pm. A further 6mm has fallen so far today(the 17th), with a constant grey steady drizzle that has set in.

I noticed a few Lightning Tracker strikes on the 15th, 15-20k's to our west from a small cell situated over the Coocoran opal fields. Didn't hear any thunder or see any CG so it may have only been intra cloud? No real structure other than the usual darkened high base cumulus to bee seen either. I would have like to see the nice line of storms approach us a bit closer on the 15th that crossed through the Bourke-Cobar region but wasn't substantial enough to hold up?

Cheers,
Shauno   

Chase Images from 16 January

A few more images from me. We did really well actually - the basin was pretty explosive given the big DP's and high temps. As DC and JD pointed out - that main cell that headed north through the Cumberland Plains hit a little convergence area. Laurier's AWN charts showed a circulation that formed right on the point of where the storm in question formed between the southerly, northeasterly and southwesterly change. Anyway we happened on the storms last throws, but saw an incredibly dynamic storm form as the larger storm was gusting out. VEry interesting dynamics, and this was the storm that brought the damage to the Cattai areas.

More at our report @ sydneystormchasers.com

Anyway here are some pics:

At Kurrajong lookout



Near Freemans Reach - first is the main storm, second two is the latter storm that formed and headed NE'sih

This system produced some quite nice rainfall across the Murray Darling catchment, though still less than what some of the model output was suggesting.

This is for the week ending 20th January

NSW / QLD Heavy rain and storms 15 to 19 January including thunderstorm of 20//1/2008

Michael, you are correct. This system has produced some very good rainfalls. As stated in another post, falls reached up to 100 millimetres across large swathes of inland Queensland although, I read some weather reports on Weatherzone that cumulative falls of up to 400 millimetres may have fallen on some isolated inland stations Thursday and Friday - 17 and 18 January 2008.

Looking at the rainfall maps Friday, there were numerous localities from Townsville to well inland in a narrow band stretching south west that had received over 100 millimetres and one place had recorded 226 millimetres.

The towns of Emerald, Barcaldine and Charleville are affected in one way although it is seen to be a boon to graziers because it is a time where dams, water supplies and stock can be replenished after so many years of drought.

One media reports suggests that 1,000,000 square kilometres of Queensland is affected by floods and another report states that 60% of the state is flooded. Whatever it is, it is a huge area that is flooded.

Today on Weatherzone, I read weather articles regarding new flooding at Normanton in far northern Queensland and possible new flooding at Rockhampton due to the Fitzroy River being unusually high.

The system moved south, south west Saturday and falls reached 70 millimetres around Cobar. By the time it reached southern New South Wales, falls still reached 50 to 60 millimetres (eg 58 mm at Albury).

However, in North East Victoria, some rainfalls reached 106 mm at Mount Buffalo and nearby areas. There were isolated instances of flash flooding in hilly areas NE of Melbourne Saturday.

This system has delivered some big rainfalls and has left flooding in large areas in its wake.

Not to mention two thunderstorms that swept across parts of Sydney Sunday afternoon. One at 4 pm that dumped 40 millimetres of rain over a rain gauge in the Royal National Park and 28 millimetres at Cronulla. This thunderstorm is responsible for two deaths occurring at Maroubra in which three people were inside a stormwater drain during this event which flooded.

The second thunderstorm swept over Blacktown and regions after 7 pm and brought a short but very heavy downpour, some 13 mm in a little over 10 minutes (Seven Hills Rain gauge from BOM) and a rain gauge in Baulkham Hills received 28 millimetres in a short period of time as well.

Both storms were relatively small but brought short sharp heavy showers / downpours in the affected regions.

The drainage system where I was could not cope too well from the rainfall intensity generated by the second thunderstorm. 

Harley Pearman

20th January 2008 - Storms southwest and southern Sydney

There were a few pros and cons to storm development and intensity anticipated on the 20th January. Storms were almost certainly going to fire and the shear was half decent given the time of the year. There was ample moisture in the boundary layer and the moisture profile was certainly ideal. Cons were the not so cool temperatures aloft especially in the upper levels meaning low topped storms were more of a certainty.

Given I had to be in Carlingford on this evening, I decided to take a detour to chase this cell despite missing out on its early development. It was high based but at times interesting nevertheless. The updrafts were crisp aloft given the dry air.

Here is a picture of the updrafts:



Regards,

Jimmy Deguara