Storm Australian Severe Weather Forum

Severe Weather Discussion => Australian Severe Storms, Weather Events and Storm Chasing => Topic started by: David C on 12 January 2006, 08:55:43 AM

Title: NSW Storms 11-12 Jan 2006
Post by: David C on 12 January 2006, 08:55:43 AM
A cell has developed over the western suburbs of Sydney and has tracked generally ESE. High-based and with a shelf (not suprising since PBL is a bit dry), heavy rain and some pulsing lightning here at North Ryde. In fact the booms tempted me to go out on the car park roof to shoot some brief video.... hopefully with a few bolts.

Other cells firing near Camden right now (3:30 UTC).

Title: RE: NSW Storms 11-12 Jan 2006
Post by: David C on 12 January 2006, 09:22:07 AM
There looks to be a storm SE of Bulahdelah at the moment with a somewhat anomolous (N) propogation. Between 2:40 and 3:40 UTC the storm has developed updrafts on the northern flank. It is not particularly intense, just into the red (btw does anyone have a conversion chart showing dBZ for the BoMs color scale?). The cell might mark the southern extent of a boundary with NE winds pushing in a little up there.

3:00pm edit - storm is collapsing now!

3:47pm edit re. radar

BoM Old:

    * VIP 1 (Level 1, 18-30 dBZ) - Light precipitation
    * VIP 2 (Level 2, 30-38 dBZ) - Light to moderate rain.
    * VIP 3 (Level 3, 38-44 dBZ) - Moderate to hevay rain.
    * VIP 4 (Level 4, 44-50 dBZ) - Heavy rain
    * VIP 5 (Level 5, 50-57 dBZ) - Very heavy rain; hail possible.
    * VIP 6 (Level 6, >57 dBZ) - Very heavy rain and hail; large hail possible.

BoM New:

(http://www.bom.gov.au/reguser/by_prod/radar/images/Radar6-15.gif)
This corresponds to the 6 levels of shading on the radars for the different intensity rainfall rates.


TWC
Level 1, 12-23 dBZ
Level 2, 23-28 dBZ
Level 3, 28-31 dBZ
Level 4, 31-34 dBZ
Level 5, 34-37 dBZ
Level 6, 37-40 dBZ
Level 7, 40-43 dBZ
Level 8, 43-46 dBZ
Level 9, 46-49 dBZ
Level 10, 49-52 dBZ
Level 11, 52-55 dBZ
Level 12, 55-58 dBZ
Level 13, 58-61 dBZ
Level 14, 61-64 dBZ
Level 15, 64+ dBZ
Title: RE: NSW Storms 11-12 Jan 2006
Post by: Matthew Piper on 13 January 2006, 03:21:09 PM
I saw that storm David from Orchard Hills. It definately had some really nice CG's :) Unfortunately I didnt get to capture any as I was driving at the time.

After the Sydney storm had passed I met up with Jimmy along the Putty Rd and headed north towards Merriwa and Dunedoo where we were treated to a rather nice lightning display. The lightning wasnt all that frequent near Merriwa, however the rain when we drove through the storms was extremely heavy and severely reduced our visibility. Later on in the evening we arrived at Dunedoo where we decided to stay for the night, but before we went to bed we headed out to watch the most lightning active storm of the day which was near Mendooran. Rain from the southerly facing anvils unfortunately interfered with our ability to take photos, however Jimmy did capture some nice bolts on tape.

Today I parted with Jimmy as I had to head back home for a prior commitment. Hopefully he was able to get some good lightning or structure out of the storms that developed near Coonabarabran today.
Title: RE: NSW Storms 11-12 Jan 2006
Post by: Jimmy Deguara on 13 January 2006, 06:49:26 PM
Hi,

The storms in the NW Plains near Quirindi were quite severe with all 3 - damaging winds, large hailstones to about golf ball size and very heavy rainfall! I intercepted the main storm near Breeza and then eventually intercepted the new development attempt north of Nundle. Sufice to say a very long chase!

Pictures etc will be online soon! I need some rest.

Regards,

Jimmy Deguara
Title: RE: NSW Storms 11-12 Jan 2006
Post by: Michael Bath on 14 January 2006, 02:36:19 AM
Sounds nice Jimmy - can't wait to see the next lot of photos :)

Nothing too much up here today in the weak shear. Some "backwards" sort of cells late afternoon, which eventually gave us a bit of a lightning show between 8 and 930pm, though almost all lightning was in-cloud from my vantage points.

(http://australiasevereweather.com/temp/forum/photos/2006011201.jpg)

MB

Title: RE: NSW Storms 11-12 Jan 2006
Post by: Jimmy Deguara on 14 January 2006, 04:28:32 AM
Hi Michael,

Not many photographs - but lots of video. I was on the move with this storm new Breeza and core punched it! I think I will have to resort to video stills for this lot. A couple of photographs were taken whilst enroute.

Regards,

Jimmy Deguara
Title: RE: NSW Storms 11-12 Jan 2006
Post by: David C on 14 January 2006, 05:06:02 AM
Following our discussion, here is the Newcastle 256K loop Jimmy.
http://radar.strikeone.net.au/?fuseaction=loops.main&radar=042&numberofImages=15&dateStart=1137033000&dateFinish=1137051000

The Breeza storm develops south of Gunnedah. This storm seems to initiate around 4:00 (UTC), there is an updraft merger between 4:40 and 4:50. The cell reaches a maximum intensity of 61dBZ (very impressive at that distance, >200km) some 15km NW of Quirindi and by 5:40 UTC is really collapsing. Another updraft has developed just NE by 5:30 UTC and reaches maximum intensity by 5:50UTC (6:00UTC missing from the loop I created). By 6:20 it is appears as a complex in a weakening phase.

Anyway these were some very intense cells.
Title: RE: NSW Storms 11-12 Jan 2006
Post by: Jimmy Deguara on 14 January 2006, 09:14:01 AM
Goodness my first cell merger!

Now this means that a cell had to be moving left unless there was an expansion of the cells in question.

It is not often that I am concerned about the severe weather that happens in a storm. This was one hell of a ride - at one point I was getting concerned by the large hail being rocketed into the vehicle that I looked for a place to stop (gosh I am a whimp). And then I thought what the hell is the car in the rear vision mirror doing moving past. It was so intense I had not realised I was being followed by a truck - a semi-trailer! I could not even see the side of the road when attempting to stop and face the wind!

One thing I recall which always excites me is that I went into the storm, it obviously closed in with violent wind and heavy rain but then further in it got darker! The suspense of what might happen here puts you on the edge of your seat!

Anyway for those reading this, please note that this ends a day of frustration waiting in 38C with dew points of 18 to 19C - how could this be with our dreaded W wind blowing! The cap had to eventually break with so much energy. it did so slowly though and earlier storms looked garbage garden variety with some strong winds and microbursts and merger lightning. I was absolutely stunned to find that one of these had broken and organised with an excellent rain free base.

The ride home was awesome and thanks David for the chat. In total I went from Dunedoo to southeast of Dunedoo briefly for a phone service pickup during the morning and a model run and then target the northern side of the Warrumbungles and simply waited near Mullaley. After another check of the models there (thanks to the Post Office agent), I headed for Gunnedah merely because the meaty cumulus were struggling in the lower layers. There was a storm to the east but this had broken through but was not very impressive to warrant a drive to the Northern Tablelands. I remained near Gunnedah until finally one updraft showed signs of crispness and went straight through! This became the first cell intercepted and then organised as suggested above. So I headed down towards Quirindi and turned off to Werris Creek and then towards Quirindi - on towards Wallabadah and then on to Nundle up to Hanging Rock and then around to Top Dale and down to Gloucestor and Sydney. I must have done based on fuel needing a top up about 700 to 800km - one of the hardest chases in a very long time.

Regards,

Jimmy Deguara