Topic: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007

[David Brodrick]

Flash Flooding at St George

The BOMs weather station at St George recorded 82mm last night and gusts to almost 80km/h before the anemometer broke.

However some bloke reports he had 108mm in half an hour and then another 20mm later on. Here is the ABC News article:
http://www.abc.net.au/news/stories/2007/12/21/2124811.htm

Severe storm floods streets, causes 'chaos'

A severe thunderstorm has lashed the southern inland Queensland town of Saint George, flooding streets, houses and a pharmacy, and bringing down trees and power lines.

The Queensland Fire and Rescue Service says it received a number of calls for help.

Resident Roy Aldridge says 108 millimetres fell at his house in half an hour, and there was another 20 millimetres later in the night.

Mr Aldridge says the water was knee-deep across roads, and the wind caused chaos.

"It was interesting to see people try to negotiate the southern end of Scott Street through all the limbs and branches," he said.

"Further down the street there's a house with a large jacaranda just blown to pieces."

[Shaun Galman]

Hi guys,

Good to see some great reports from VIC after all the amazing storm action here in NSW!

Flash Flooding at St George

The BOMs weather station at St George recorded 82mm last night and gusts to almost 80km/h before the anemometer broke.

I can understand these claims David. We had three HP cells come through our area yesterday evening also. The first built to our north around 3pm and came across the western edge of town. This cell had a nice dark base on the leading edge, a nasty rain core and was fairly active.
The second cell came in directly across town from the north west at 4:37pm with alot more rain ferocity and was carrying a nice inflow shelf (I managed a couple shots from my roof quickly before the deluge). This storm wasn't as active as the first, only some minor intra-cloud light. It looked very dark and impressive upon approach.
The third cell and most severe rolled in directly behind the second around 6pm and let loose with a ridiculous barrage of CG throughout town! We heard one pretty close strike that lit up the house (even with the blinds drawn) and made us jump with the resulting CRACK of thunder! I would've guessed this strike was anywhere within a hundred metres? The rain was torrential to say the least and the totals for the three storms came in at 38mm.

It's the first time that I couldn't manage any sort of lightning photography at all due to the constant heavy rain, this is an extreme rarity for me as I will usually try anything for a good photo? Just a little too dangerous, unpredictable and wet this time!

Cheers guys,
Shauno 

[Carlos E]

Had a pretty noisy storm in terms of thunder this morning in Adelaide.

Some notes about today thus far:

Gusts of 120km/h at Broken Hill;
Gusts of 120km/h at Coober Pedy;
Gusts of 105km/h at Wilcannia.

[Shaun Galman]

Hi all,

Just got back from a chase..not alot of photos...storms were inbound at 80km/hr so some nice approach shots, but after that just heavy rain and isolated embedded storms....so humid Id swear it was singapore. Will post some pics shortly

John: I cant stress how much I agree with you about the tropical feeling to the weather! I think they need to move the tropics line further south to cover all of us in the SE!

21 December 2007. Upper Western NSW Storm Update & Photo
I just took a few shots of yet another HP cell, and like John, a few nice approach shots but no actual substance to the storms. This storm broke the cap around 4:30pm and came across the Ridge just to the north at 5:15pm when I shot the small panorama below. I heard a few rumblings but didn't actually catch any CG, but they would surely be out there. Also in the shot below you will notice the build line in the distance. These storms are on the approach now so I will keep an eye out in the coming hours


Cheers guys,
Shauno

[Michael Bath]

This was aired on Channel Seven this evening. A tornado was reported near Ballarat, VIC 20th Dec 2007. Really need to see much more of the clip to see what is going on. Seven didn't show enough and had their stupid logo all over it.

---> Video Clip < ---

[Jeff Brislane]

MB, I saw the same footage tonight and the voice on the camera sounded kind of like that guy who had the website stormplanet whatever his name was. It also looked remakably like a tornado from the past that occured near Booloroo in South Australia. can you get some radar up of the storm?

Jeff.

[Michael Bath]

Interesting cell to your east now Shauno - hope you get a show from that or that later stuff still moving in from the SW.

Some nice falls about again in Melbourne - thanks for reporting that John. Hopefully many sites have picked up some great totals.

Jeff - the footage is by Clyve Herbert - I assume taken looking at the cell which passes south of Ballarat.

Some data for the event

---> Melbourne 128km radar loop


Melbourne 00z


GFS analysis Thursday 20/12/2007 06z

Instability: CAPE / Lifted Index

Relative Humidity: 0300 / 0500 / 0600 / 0700 / 0850 / 1000

Temperature: 0300 / 0500 / 0700 /  0850 / 1000

Winds (knots): 0200 / 0300 / 0500 / 0600 / 0700 / 0850 / 0925 / 1000

Note the instability over TAS as well on the GFS charts - there were some storms mainly in the northeast of that state.

MB

[Jimmy Deguara]

Here are some links that may be found interesting:

http://bendigo.yourguide.com.au/articles/1149541.html?src=topstories

Here is the Weatherzone link to the pictures of the tornado

http://forum.weatherzone.com.au/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=000348;p=11

I wished there were more.

Regards,

Jimmy Deguara

[Jeff Brislane]

It certainly doesn't strike me from the gfs plots as an enviroment conducive to tornadoes but there could be a number of other factors involved that basic gfs plots don't show. The wind shear is quite linear above 850mb for starters. Also the radar echo is far less impressive than the later echos of the two obvious supercells which moved north into NSW.

Jeff.

[Jeff Brislane]

I just checked out the photos on that other forum. Is it a gustnado? It certainly looks like it developed along the gust front of the cell to me anyway. The cell doesn't look like a regular supercell as such.

Jeff.

[Jimmy Deguara]

Jeff,

I was tending towards gustnado given the feed from the rain and what seems to be the short lived nature. Perhaps vorticity as the storm tended towards outflow dominance.

There is hardly any rotation I can detect on the video. A tornado of that size from a 'mesocyclone' could easily have noticeable rotation from that distance I would think.

Take not of the distance one of the videos was from the Dunoon tornado 26th October 2007. Even from 2km away, rotation and upmotion was easily visible. If any rotation is apparent, can anyone discern whether it is anticyclonic?

Further, is that inflow on the left side of one of the images or is it an extension of the shelf cloud? It is obvious that a shelf cloud passes over in one of the photographs.

Is doppler available from this distance out?  The Bureau according to the article are still checking to see whether it was a tornado.

Comments?

Regards,

Jimmy Deguara

[Shaun Galman]

Hi all,

Interesting cell to your east now Shauno - hope you get a show from that or that later stuff still moving in from the SW.

G'day Michael, I took a few shots of the storm line you mentioned around 7:30pm, saw a few bolts here and there but was I mostly impressed with the massive size and height of the structure! I saw it break the cap twice, the first time showed some typical white Pilus then a few minutes on while still rising it seemed to find another cap and show a thick, somewhat dense brownish/grey Pilus (could this be possibly from extremely heavy moisture aloft?) This storm soon became a gust front of sorts with several dense rain cores along it's length, sparking some nice activity.

I found myself out at 3:25am this morning once again getting a few photos of a highly active distant storm to our south west, somewhere near Walgett, possibly 80k's or more away. This storm was so active that it was causing power disruptions from way out there!

I saw the "tornado" on the channel 7 news last night also guys, the wall cloud looked pretty mean and impressive underneath a massive parabolic/lenticular cloud structure! Reminded me of something you'd see from the Texas Panhandle or Oaklahoma! (the state, not the musical? lol) I'd gather these warm, humid conditions coinciding with a cold front from the south would give rise to a few tornado's over the coming weeks, providing this current trend continues?

The rain has certainly set in this morning! It's so dark that it feels like nighttime? Here's a few current numbers for you- Temp- 23.6º. Humidity- 66%. Pressure- 989.70mb and steady. Wind - North 1.1kph. Rain since 6am- 31mm.

I'll compile a short report and get a few shots from yesterday evening and early this morning up today at some point.
Cheers from a VERY wet, muddy and surprisingly green Lightning Ridge!
Shauno
 

[Jeff Brislane]

Hey Shaun I can't believe how green lightning ridge is in your photos! I thought it was semi-arid! You have some very impressive cells to your south last night, and that cell you mentioned with the amazing lightning show was probably the one responsible for the massive rainfall totals around the Warrumbungles. Coonamble has topped the rainfall list this morning with a massive 171mm to 9am! And there are several guages that reported over 100mm.

Jeff.

[Michael Bath]

Given the significance of the other cells on 20th December 2007 here's some radar loops for posterity.

---> Yarrawonga 128km / Yarrawonga 256km


Sure have been some impressive rainfall totals Jeff !   These to 9am 22nd Dec

NORTHWEST SLOPES:
Barraba Tce Blackville  56 Breeza  16 Gunnedah  16
Gunnedah Ap AWS  16 Mullaley  23 Quirindi  11 Tambar Springs  89
Tamworth Ap AWS   4 Weabonga   8 Woolbrook   2

NORTHWEST PLAINS:
Come by Chance  95 Gwabegar  54 Moree Ap AWS   2 Mungindi   4
Narrabri AP AWS   2 Pilliga  43 Walgett Ap AWS  35 Wee Waa   4

CENTRAL WEST SLOPES:
Binnaway 112 Coonabarabran 141 Coonabarabran AWS 116 Cowra Ap  32
Cowra Ap AWS  32 Cowra RS  31 Cudal  27 Cumnock  31
Dubbo Ap AWS  61 Dunedoo  49 Forbes Ap AWS  32 Manildra  22
Mendooran  69 Parkes  19 Parkes AP AWS  34 Tooraweenah 106
Wellington  51

CENTRAL WEST PLAINS:
Condobolin Ap AWS  40 Coonamble 171 Coonamble AP AWS  60
Gilgandra  81 Gulargambone 125 Marra Ck  64 Mudall  47
Narromine  65 Nyngan 102 Peak Hill  31 Trangie AWS  73 Trundle  57
Tullamore  77 Yalgogrin Nth  18

[Shaun Galman]

Hey Shaun I can't believe how green lightning ridge is in your photos! I thought it was semi-arid! You have some very impressive cells to your south last night, and that cell you mentioned with the amazing lightning show was probably the one responsible for the massive rainfall totals around the Warrumbungles. Coonamble has topped the rainfall list this morning with a massive 171mm to 9am! And there are several guages that reported over 100mm.

Jeff.

Hi Jeff,
It is great to see it so green out this way! We are definitely semi-arid as you say but you'd never guess it now! My father and a few other long-time locals are saying this is the best summer rain since the 70's -early 80's. I cant recall such a burst of greenery since the last flooding in 1984! Our only trouble now is that to access most of the opal fields you need to cross the dreaded black-soil lakes. Some of these contain black-soil upto and beyond 80feet in depth! We may not  be able to get out to work for weeks?, though there is kind of an upside to that I guess
From the build line I witnessed developing to our north-west yesterday evening I can see why the totals were up into the high 100mm's most places to our south-east!

Cheers,
Shauno