First severe storm chase of 2007 SW Queensland Australia

[Jimmy Deguara]

A Happy New year to all.


SOme of you may have noted of the incredible drought conditions across Australia. It seems we may be in El Nino breakdown mode.
Consequently, moisture has fed inland with a cut off low creating conditions leading to heavy rains across far NW New South Wales and SW Queensland. Most of this came from active storms particularly during the 1st to 3rd January 2007.
I thought I would share with all of you one particular cell of the chase. It occurred in far western Queensland in a region known as the Outback. What we consider as major towns are separated here by minumum 130km and even 250km or more. What it also means you are limited to road choices - spaced about 250km apart. Gravel roads are not an option and are closed after even moderate rainfall.
On this day, for the first time in many chases, we had deep layer shear with winds curving in on the southern quadrant of the low. Early ongoing convection occurred to the south and perhaps aided in the formation of a boundary slowly spreading north. It also helped cool temperatures to a reasonable level to close the gap between the dew point spreads. The end result emerging out of the inflow dust was the following cell:
Click on thumbs for the larger images


More available on this page

Regards,
Jimmy Deguara[/img]

 

[Jimmy Deguara]

More pictures from the event

 

[Paul Austin]

You should try to stitch some of the photos together if they overlap and were taken at nearly the same time. It could make a nice panorama. Great pics.

 

[Marko Korosec]

Amazing images, Jimmy! I like the dusty inflow and a massive shelf above in your second post, excelent colors! It makes some memmories...
See you in few months

Cheers!

 

[Jimmy Deguara]

Hi guys,

Yes the photographs were taken with panorama in mind but I never get around to doing it The storm was one of the most inflow prone storms I had chased in Australia but definitely one with the deepest inflow!

Regards,

Jimmy Deguara

 

[Jimmy Deguara]

LP supercell Sydney Australia and some lightning

Although thought to be rare, LP supercells have now been observed a few times in western Sydney. This one occurred last Friday 12th January 2007. It was a very hot day 40C and developed along a boundary possible dryline. Lapse rates aloft according to the models were reasonably decent for what we usually get - 700 to 500hPa being about 19C.





Regards,

Jimmy Deguara

 

[Andrew Khan]

Your very lucky indeed for catching these storms man, I am sure you have an idea of how lucky you are. That storm looks very dusty man, and those photographs of that shelf cloud are great.

 

[Jimmy Deguara]

Andrew,

I can tell you if you look at the map closely, despite it being the target, yes we were luck the storms made it to us!

I found the event itself very interesting and spectacular as it is not common to get strong inflow.

Regards,

Jimmy Deguara

 

[David Drummond]

More pictures from the event

It's unbelievably amazing how much that area looks like parts up on the caprock in NW Texas! If you had not told me where those were shot, I could have sworn it was near me, yet it was on the other side of the world! Very cool!

 

[MJ Poore]

Nice stuff Jim. Looks like where I live at the moment. Lots of tropical and mid latitude air mixing. A couple of scenes from my cameraphone this past week...

 

[Jimmy Deguara]

MJ Poore wrote

Looks like where I live at the moment. Lots of tropical and mid latitude air mixing.

Yes tropical air is getting inland this year - for some in that region the first time in 6 years. That means no real decent rains since 2000!

David you are so correct but there are some differences. The region has reddish soil that you do not dare travel on in wet weather. It is flat and has low shrubs due to very low annual rainfall - less than 250mm ( 10ins ) but a very unreliable rainfall in that. It borders desert and if you head slightly west you begin to see some isolated sand dunes and salt lakes (most often dry). This region is mostly 200metres or less. It is known as the channel country where floods stream down in multiple channels -small rivers. It is beef cattle country with very large stations (you call ranches) except these are measured in square miles! The towns in this region can only rely on under ground artesian water from the Great Artesian Basin. Bordering desert the region gets very hot thence most storms are higher based - this was very unusual.

Conversely, the caprock is elevated I guess to a level of 500 to 1000 metres or even more. It to me has more fertile soils and far more reliable rainfall despite some of the recent droughts or at least availability to water. The Caprock is significantly more densely populated.

Anyway, that gives you some picture.

Regards,

Jimmy Deguara

 

[David Drummond]

David you are so correct but there are some differences. The region has reddish soil that you do not dare travel on in wet weather. It is flat and has low shrubs due to very low annual rainfall - less than 250mm ( 10ins ) but a very unreliable rainfall in that. It borders desert and if you head slightly west you begin to see some isolated sand dunes and salt lakes (most often dry). This region is mostly 200metres or less. It is known as the channel country where floods stream down in multiple channels -small rivers. It is beef cattle country with very large stations (you call ranches) except these are measured in square miles! The towns in this region can only rely on under ground artesian water from the Great Artesian Basin. Bordering desert the region gets very hot thence most storms are higher based - this was very unusual.

Conversely, the caprock is elevated I guess to a level of 500 to 1000 metres or even more. It to me has more fertile soils and far more reliable rainfall despite some of the recent droughts or at least availability to water. The Caprock is significantly more densely populated.

Anyway, that gives you some picture.

Regards,

Jimmy Deguara

Actually Jimmy, you have just described much of West Texas. The dirt is very much on the red side. We don't notice it as much, but people from up north and out east comment on it all the time when they are in the area. It's extremely flat out here. Our average annual precipitation is only around 18.5 inches and as you say, often unreliable. Just to my southwest is an area known as the Chihuahuan desert. On your way there you pass through an area known as the Monahans sand hills that stretchs a pretty good distance. There are a number of salt lakes, both dry and not around the area. As you mentioned we have the ranches too. Some measuring in hundreds of square miles! Most of the main city water like for the City of Lubbock comes from a lake in the Panhandle, but most of the rest of the area uses wells that come from an underground water source known as the Ogallala Aquifer. Temps here in the summer can reach above 100 degrees! Most of our storms in July and August are of the high based variety, often with quite dramatic downbursts due to the air being so dry at the surface.

I suspect the two areas are more alike than different. I hope to visit, and maybe chase, down that way some day.

 

[Jimmy Deguara]

Hi David,

Yep chased and travelled through those areas over a few years now.

Here is a climate listing for Bourke 100km south of where the supercell occurred on the 2nd January 2007

http://www.bom.gov.au/climate/averages/tables/cw_048013.shtml

Regards,

Jimmy Deguara