Great Northern Downs Wallclouds! 
(And Trees!)

January 12, 2002

This was an interesting day of ups and downs.  The previous day saw two supercells on an interesting southeasterly surge that produced and maintained a line of severe thunderstorms for over 1500km!  The trough was now moving inland, and Capricornia was looking the better area, but I couldn’t go that far.  I had two choices, the Wide Bay/Burnett region, or into the Northern Downs and the southern central highlands and coalfields district.

Lured by the temptation to explore the Wide Bay region more, I decided to head north.  But I got distracted when I came across a storm damage path just south of Gympie, and decided to spend an hour doing a damage assessment survey and talking to some of the farmers about what had happened.  They were recovering from their losses, many of their fences had been destroyed from trees falling over them – the tree damage was incredible!  Not one tree did not suffer at least some sort of damage.  Trees and large branches had all been pushed off the roads and were piled up on top of each other.  Some of the cattle were injured after being cut from hail, and there was a lot of structural damage to sheds etc.  But little damage to houses amazingly!

After that I continued north into Wide Bay.  The skies eventually cleared to become broken up.  I took an inland route, towards Munduberra.  I noticed some showers were developing – they weren’t large, but they were developing.  They looked like coastal showers actually – although the updrafts were slightly stronger and a little more crisp than the ‘average’ coastal shower around SE QLD.  In amongst negotiating a loan with a bank manager…I arrived at Ban Ban Springs, with a rather pleasant sight to my south!  I decided to grab a bite to eat and then find an advantage point to watch.  Needless to say, I won’t be in a hurry to buy a cardboard-flavoured pie at Ban Ban Springs again!  Which is really just a roadhouse, no real town at all.  I sat on a dirt trail through a field and watched.  The line of CJs had developed into storms, static wasn’t too bad – once every few seconds! 

And I could hear the sweet and familiar sound of distant thunder every minute or so.  But the line was struggling, it’d put up an encouraging pulse every so often, but then it’d collapse.  It was moving NE, so I decided to head NE to Biggenden. 

Not before taking some footage of a rather amusing sign though!

As I headed NE I noticed the line starting to weaken – when I got to Biggenden it had become totally overcast, but static was constant!  I have Doc a call and asked what was happening and he mentioned it had all flattened out into rain, although there were massive storms in the Capricornia.  There was however, a large lightning area to the west – so I headed towards Munduberra, which was about an hour to my west.  However, it was just thundery rain with the odd CG – a little bit of an anti-climax.  I had to decide whether to go home (and risk absolutely nothing), or to try and get something else.  That would mean going due south into the Northern Downs, adding an extra hour on the trip to get home as it was less direct.  Doc said there were some isolated cells in the Northern Downs, to the SW of the rain area.  So I decided to take the chance and head down a deserted road into the Northern Downs.  Deserted was an understatement!  I passed a total of one car over 200km (coming the opposite direction) – yet this was the main road linking the two areas!  The first 50km or so was quite treed in, I had some moderate-heavy thundery rain, and caught the glimpse of the occasional CG when the rain was quite light.  There was a fair bit of water on the road…but structurally there was nothing to see.

When the trees finally let up, it gave way to much flatter and more rolling hills – I saw some storms to the SW, they looked quite large and I thought they were relatively close (about 50-60km away), well – try 150km away!  They were massive!!!  It wasn’t until I started realising how long t was taking me to get closer that I realized how large they were. 

They were sitting just east of the Leichardt Hwy, but still west of Chinchilla.  It took me ages to get closer to them – but the structure!  Ahem…well, I lost count of the number of times I nearly drove off the road looking at extremely deep (although not large) mammatus hanging down like serious upside down convection!  I was annoyed it didn’t come out that well in the photos/video – it doesn’t do it justice!  And I could see the outflow/shelf region to the SW. 

The storms were impressive in height…a friend of mine flying back (also into weather), said the storms were hitting at least 45,000ft.  This certainly seemed like a good estimate – possibly higher, but from where I was it was difficult to tell as a lot of the anvil shield had spread over me!  I must say very ‘guiltily’ that on a deserted road with massive storms in the distance, it was a struggle keeping the speedo dial on ‘100.’

As I got closer, the mammatus got more defined and the outflow region was looking nasty – but I also got entangled up in more trees down towards Chinchilla – an absolute pet hate!  However, in my struggle to find a clearing, I found a road that went through a paddock.  I took it and screeched to a halt.  A massive wall cloud was dragging along the ground to my WSW from one of the storms!  To the north of that storm (by about 30km), a more rounded lowering sat underneath the updraft – a strong candidate for a wall cloud.  And to the south of this storm…well, I won’t say it – it was a little too far away to see!  But needless to say my jaw dropped to the ground!  And to the NW, I could see behind the line – nothing but clear blue sky!!!  It’s the type of situation you’d imagine yourself to be in the US for – it’s rare you can see behind the line of storms and see blue sky, normally it’s cloudy.  But this was the case – and I was amazed at one of the wall clouds, probably the largest I’ve ever seen (about 500m wide at least!)

The other problem I was going to encounter was that I would run out of Sunlight…the Sun would be going down in about 10-15 minutes, which was yet another pain!  I sat and waited longer…slowly the northern (what I can only assume to also be a wallcloud) to the north weakened and became absorbed into the base.  The southern one kept it’s shape for longer though, although both produced rapid scud movement under their bases and drew the scud into themselves!  The temptation to get closer was too great – I would lose sight of them anyway due to the Sun going down, and the lightning from these storms weren’t as frequent as the storms further north.  The road as I feared, was mostly trees to Chinchilla.  I caught brief glimpses of the wallcloud, but it was dark.  I wasn’t too worried about getting too close in the dark, the storm was still a good 20-30km away and wasn’t moving quickly.  At Chinchilla, I made another call to Doc and grabbed some greasy unhealthy food at the servo and found a little advantage point and sat and watched the lightning to the west.  It wasn’t overly frequent…once every 10 seconds, but it was nice to watch while relaxing and eating dinner!

I contemplated staying the night as it was about 8pm and it’d take just over 4hrs to get back to Brisbane.  But some storms developed to the SE of Chinchilla, and I decided that it’d at least give me lightning back to Dalby (which it did!) so I’d have something to look at!  Thanks to Jane and Macca who kept me occupied while driving back at night on the phone!

It’s amazing how quickly a chase can change…and how brief the best part of the chase can be!  At the end of the day it left me wondered whether I had actually seen what I had seen.  It took a while to finally sink in – as the best part occurred so briefly!  But that’s what chasing was all about.  All up it was actually my longest daytime chase…I did just over 1100km.