Best light show in years!!!!!

Well, what can i say, such a rare and exciting event for Canberra. 

The weather models for this event were only hinting at possible storms for the Canberra region on the 29th, GFS and the ACCESS both in agreement that the nw of the ACT would be more likely, but not necessarily close enough to warrant a light show over the city itself. A classic pre-frontal trough formed in western parts of the states and advanced eastwards, forming a boundary area called a dryline - the boundary between 2 parcels of air, one moist and unstable, the other dry and stable. The other factor at play - the Brindabella range can act as blocking feature, stopping any thunderstorm from advancing all the way to the city; most quickly erode in activity and all we end up with are a few odd rumbles within a weakened cell. It is the main reason why i chase west of the ranges because it's always an issue for the ACT.

An area of instability was predicted from Wagga Wagga, right up to the northern spine on NSW. So the question was whether the area of instability was going to spread further east into the ACT.... and what mechanism would be responsible for kick starting something closer to home? 

The answer was a moist, northerly wind - this would enable more moisture to be pumped into the ACT, whilst interacting the advancing trough, and by 3pm, we could start to see cumulus towers go up to our north and west. Canberra's dew points went from 11ºC at 5:30pm, with moist northerlies flowing in, to 17ºC by 7:30pm. So very quickly the ingredients were starting to allow for storms to become more organised, with enough grunt to make it over the Brindabella ranges, and then to pick up even further. The timing was also crucial, even with cumulus towers going up, there was plenty of clear sky thanks to the dryline, that allowed for heating to create a boiling pot of moisture, until the lid well and truly blew off. 

The first storm had a very impressive NW edge, boiling updrafts with a well defined anvil spreading SE as the upper winds were firing in the upper levels from the NW. With the lower level winds turning Nth-NE, it meant that any downdraught and updraught could be separated allowing for longer, more organised storms. Since there was still a dryline present, all of the storms were high based, which allowed for tall and clear lightning. Something i haven't see for a long time. 

The first major storm over Canberra occurred around 7pm, with 3cm hail reported in the northern suburbs including Belconnen, which i also experienced at Regatta Point. I chose this location because i have identified it as a safe, undercover location to view storms moving over Lake Burley Griffin which proved to the be case when a very close lighting strike hit a granite monument at 7:32pm, as seen in the now infamous image. 

The real feature of these storms was the percentage of cloud to ground strikes. I would estimate that at least half of all strikes visible were hitting the ground. Which also added an extra element of risk whilst shooting. The benefit however was that i was able to easily gauge where the areas of charge where forming outside the rain shafts. 

When the first wave had left the area, i went home for an hour to catch up with my beloved and also get an update on radar, weather station observations and any other data that might promote further storm development. I could see another band starting get it's act together from the nw, and it was decided that given the conditions locally at hand, would make it likely that the storms would make it all the way to Canberra despite the ranges. After 7pm the lower winds started to shift around to a SE which created an idea situation where storms where running into a head wind, cause greater uplift and a pronounced leading updraught.... which then enhanced leading clear air strikes, as seen in the images taken from Mt.Ainslie after 10pm when the next wave came through.

Troy Barrett, my chase partner was available for the second wave and we spent around an hour on Ainslie looking west as a barrage of beautiful, clean and crisp cloud to ground strikes (Cgs) hammered the north western suburbs. Behind the leading up-draught we could see a well defined rain curtain which allowed us to estimate when it was time to remove ourselves from the immanent danger of the lighting itself and also any large hail and outflow winds. 

With some too-close-for comfort Cgs, we retreated back down off the mountain. There were plenty of other observers still enjoying the show as we left for Regatta Point. We only had just made it my original location when we got hit by a powerful, short lived microburst. A microburst is a violent downdraught that is air being dragged down by rain and hail that once it hits the ground, spreads forward. If the upper level winds are strong, as was the case in this event, those winds can enhance the speed of the descending air. Microbursts are common within severe storms, they can be wide or narrow, but still their damage to buildings, trees and other structures can be easily defined by straight line damage. The microburst we sustained lasted only a couple minutes, but had managed to shred trees of their branches and limbs around the Regatta Point area, one only narrowly missing my car..... glad i chose younger trees to park near! We estimate the winds reached 120k/h plus, and i must say, it is the fastest way to get yourself soaked in water! 

The final encore came at around 1am with another approaching line from the west. At this point the temps were dropping fast, with a cold southerly feeding in. We thought that this might kill off the storm, as usually cooler winds can drain energy from any cell. However, this proved to be wrong, as this epic line fired on the upslope of the ranges. Quite literally, it took only 5 mins from something that was mediocre, to a line that was producing several strikes a second! In the incredible display, a clearly defined shelf cloud formed as the storm moved into the southerly head wind. You can see in a couple of the images the photogenic cloud formation and the intense discharges. I haven't seen such an active cell in a very long time. We noted at the time that the radar echo had a marked hail core, which with the cooler environment, large, solid hail was expected in the southern suburbs. 

We rounded out the night by reviewing our images at Troy's place nearby, which i came home to quickly review my images on my monitor. I had to pinch myself that finally after all these years, i have finally ticked off 2 of my boxes: 1/ to take an image of a lightning strike within 100m and be able to tell the tale, and 2/ to take images hitting a city lights...... and boy, did tick those boxes!

First image is a very close cg taken at Regatta Point, landing about 100 metres away. My closest strike caught on a camera to date! Those white dots are 2-3cm hail stones caught in suspended light, not dust bunnies:) 

Click to enlarge following images....

This Cg is hitting a tree near the golf course north of the city, which i'm keen to find the tree itself to assess the damage to it. Taken from Mt.Ainslie looking west. 

Another image hitting a paddock in the northern suburb which i'm yet to identify.

This strike is hitting North Lyneham.... someone would have heard a very loud crack of thunder, that's for sure!

The barrage of Cgs striking the Brindabellas. The next 2 images were taken at around 5 secs each, so you can see how active it became, and the associated shelf cloud revealing the strong outflow.... incredible!!!