Topic: NSW Severe Storms 5 - 7 January 2010

[Kristy Norman]

A Severe Thunderstorm Warning currently out across areas of central inland/southern NSW. This storm pushing up South East of Wagga Wagga, a lot more contracting east towards the mountains, bubbling away nicely.

[TroyVR]

For people in parts of the
Sydney Metropolitan and
Blue Mountains/Hawkesbury areas.

Issued at 4:11 pm Tuesday, 5 January 2010.

The Bureau of Meteorology warns that, at 4:10 pm, severe thunderstorms were detected on weather radar near Blaxland, Springwood and Penrith. These thunderstorms are moving towards the northeast. They are forecast to affect Kurrajong, Castlereagh, Cranebrook and Londonderry by 4:40 pm and Richmond, Wilberforce, Windsor and the Wollemi National Park north of Kurrajong by 5:10 pm.

Large hailstones, very heavy rainfall, flash flooding and damaging winds are possible.

The State Emergency Service advises that people should:
* Move your car under cover or away from trees.
* Secure or put away loose items around your house, yard and balcony.
* Keep clear of fallen power lines.
* Keep clear of creeks and storm drains.
* Don't walk, ride your bike or drive through flood water.
* Unplug computers and appliances.
* Avoid using the phone during the storm.
* Stay indoors away from windows, and keep children and pets indoors as well.
* For emergency help in floods and storms, ring the SES (NSW and ACT) on 132 500.

The next warning is due to be issued by 5:10 pm.

A more general severe thunderstorm warning is also current for the SOUTH WEST SLOPES and parts of the HUNTER, METROPOLITAN, CENTRAL TABLELANDS, SOUTHERN TABLELANDS, CENTRAL WEST SLOPES, CENTRAL WEST PLAINS, RIVERINA, UPPER WESTERN and LOWER WESTERN districts.


Heard reports of hail damage to vehicles in the area and very heavy rain also.

[Richary]

I initially heard reports before 2pm of a storm near Warragamba. By the time I came out of the next appointment near the city about 3 I could see a massive shelf cloud covering half the sky with some nice cumulus behind it. After stopping at West Ryde shops on the way home I came out to be greeted by some very nice mammatus cloud (photos needed touching up a bit as I forgot I had the camera on a different setting so it was underexposing by 2 F stops).

First shot is from West Ryde looking towards Parramatta, and the second is from home at Ermington where the mammatus was almost overhead.

Checked the radar when I got home and it was dumping all it's load in the lower Blue Mountains then fell apart shortly afterwards. Speaking to a colleague at Winmalee it had been very heavy rain and small hail, then they had a power cut.

[Jimmy Deguara]

Hi,

Went out for a chase once I saw things were getting going nearer Sydney. By the time I got to near Lithgow, nothing was accessible. I was just about to sit and park to wait when I noticed the cells west of Warragamba Dam that seemed to be doing not much at all earlier begin to push through the anvil again. After a check with Michael to see where they were situated (no man's land), I knew that the northern flanking line development would at least bring the action closer.

Now at this point there was nothing imprssive just life getting fed back into the storm.


By the time I was nearing Mt Victoria, the first updraft of the flanking line exploded.



It was so rapid, that I could see the updraft rising as I ventured east on the Great Western Highway. It produced and maintained an overshoot for the whole time it was in my view.






The traffic was not assisting with progress but I was able to just get under the base and play under it for a little while. Hail was evident in the lower Blue Mountains area but I can only confirm 1cm hail in 3 locations. Rain was torrential of course.

A couple of images of the rain free base prior to the dumping.





Regards,

Jimmy Deguara

[nmoir]

I managed to just miss this storm but got a view from the east north east as i headed towards it.

first pic is the considerably pretty mammatus and the second is inflow bands streaming into the storm just as it started to cut them off by raining into them , both shot on the M2 heading west

[Harley Pearman]

Central Tablelands and Blue Mountains storms 6/1/2010

I drove to Oberon and the Central Tablelands 6/1/2010 to watch distant thunderstorms form, mature and decay. Storms were forming and decaying across the Blue Mountains and the Warragamba Dam catchment area however it was not possible to chase them due to limited roads and national parks. Instead I managed to take numerous photos of storm cells at various vantage points between Oberon and Lithgow as well as the Bells Line of Road. I include three photos in this post.

The first photo was taken just outside Oberon looking east showing a thunderstorm cell powering up east of town. This cell moved north east. I attempted a chase on this storm however while I was able to close in on it, it did move over national parks and started to weaken. I decided to let the storm go at this point as I realized that I would not catch it.

The second photo was taken at a viewpoint between the hamlets of Hampton and Lowther on the Jenolan Caves Road looking south south east towards another storm cell.
 
The third photo was taken on the Bells Line of Road east of Lithgow. I attempted a minor chase as this cell seemed to be close enough however there was no road heading north towards it. The photo is taken at a viewpoint near the heavy vehicle inspection bay at Bell - altitude 1,067 metres looking north. This was the closest approach that I could make to this cell.

The photos described above are attached below.


Harley Pearman

[Antonio (stormboy)]

been very hot and humid this morning and today it has also been thundering since 11am here from the cell over Lismore. high percentage of storms today.

Antonio

[vrondes]

Some wonderful convection evident and base features in those shots from the 5th Jimmy, my take on it from home were the orphan anvils and great display of mammatus over the city.
Wednesday the 6th had some real movement in the jetstream carrying that anvil across the city very quickly, but no structure like Tuesday's,


orphan anvil around 1pm on the 5th


Blue Mountains storm that would go on to produce a wonderful mammatus display


Mammatus overhead at 4pm

Storm from the 6th with the fast moving anvil


Cheers, Con

[Ben]

Met up with Jimmy and Shane at singleon Maccas and after a wait got onto an organised storm headed towards Scone. Developed a bit of a guster before I had to go as I had work at 7pm. Jimmy and Shane stayed on this cell so I await to see their photos, it looked like a decent cell!! On my way home I couldn't help notice a storm exploding to the south and since I was taking the Golden Highway home I had the option to quickly get on the Putty Road. I took a turnoff towards Broke and saw this storm was very organised!! CG's were ridiculously frequent, best lightning I'd seen in at least two years, and the best structure I'd seen since my previous supercell late December last year! I was very excited.. and I cancelled work . The wall cloud persisted and rotated for around 30 minutes before it became outflow dominated and the cell split and took on a shelf cloud look due to either the SE'ly or the cell to the north. Missed a lightshow later.. but I ain't complaining!

  Larger - earlier storm near Scone
  
   Larger - Wall cloud when I first got there
  
  Larger
  
  Larger
  
  Shelfy after the split, weakening rapidly
  
  The last breath of the cell

[Mathew Townsend]

Beautiful kind of weather up in Northern Rivers. Alot of ordinary severe cells where that came from the coast. Those cells have been received us some nasty gusty winds and very heavy rainfalls. Up to 200mm recorded unofficially at Whain Whain. Here in Modanville i can see very heavy thundercell coming in!

[Jimmy Deguara]

Hi,

Ben, that shows nice structure and sort of the organisation I was looking for on the day! I guess the target region was fine.

Storm Chase January 6th 2010 - Hunter Valley

I happened to be in the Singleton McDonalds when Shane arrived and then later Ben. We remained near and around Singleton watching the stuff on the Putty Road develop.

Earlier Putty storm


In order to observe what was going on with the cell near Denman, we changed position further to the northwest only to see this storm collapse allowing for the other to organise.



Eventually we repositioned to Muswellbrook to watch this strong cell intensify. The cell never did get organised though and became outflow dominant. I remained a little too long on this cell and missed the cell to the south Ben got onto.






I made a dash south but passed under the left mover near Jerrys Plains. There was intense and frequent bolts - some pulsing quite well. But it was already on a rapid downward trend.

Regards,

Jimmy Deguara

[Jimmy Deguara]

Storm Chase January 7th 2010 - North West Slopes and Plains and Central Tablelands

Having had stayed overnight in the Singleton area (had things to do there), I had to decide where I would chase on the day. The air was rich with moisture with a stratocumulus cover throughout the Hunter and into some parts of the ranges. The target was going to a balance of best shear, convergence for a reasonable trigger and also instability. The modified soundings with consistently high dew points in the region near Merriwa put figures in the 2000J/kg range. This in my opinion would work with good shear and a reasonable cap. However, as I made my way into Merriwa and did a little shopping and some chat on the phone with David, the weaker towers had powered up into increasingly growing towers.

I headed west towards Coolah and from here crossed the Warrambugle Range and in position for new updraft development. Winds were quite fresh from the east and the air was very uncomfortable as the air temperatures increased. The only concern was that the storm development was moving into drier air.



Finally the westward trend slowed down and the storm began to move more northwesterly. Desipte the limited shear environment, the storm began to slowly organise and was tending to want to form a rotating updraft and preciptation curtain wrapping around the western side. A green tinge became evident in the core But with the easterly winds easing (less inflow), the storm went into a downward trend. Another updraft developed on the northern side though it remained more disorganised perhaps due to limited access to moisture and inflow.

Initial cell in mature phase


first signs of storm lowering the base a little and separating the rain free base from precipitation


Green tinge colouration


Note the side sheared anvil through the gap and base organising


Base wanted to organise but development to north and lack of heating and inflow as well as moisture may have been the culprit


Distant cells on the Northern Tablelands




The Mudgee cell
Meanwhile the storm I had seen to my south was still going strong so I made a dash for this storm. It remained quite nice and began to organise as I approached Mudgee only to find the last updraft would finally collapse.

Overshooting pulse











Cell north of Orange never really got going - limited road options and weakening storm and I was out of there:



The conditions wrong on this day were the orientation of the storms with respect to the inflow - you could have had supercells. However, given the limited shear, I thought the storms did quite well!

Regards,

Jimmy Deguara