Tuesday, February 05, 2019


This summer we have experienced more than our fair share of thunderstorms.
They usually arrive late in the afternoon and put on an exciting light and sound show.
Sometimes lightning strikes are very close. Our neigbour had some damage done to their entire electrical network and appliances due to one.
What has been strange about this season is that while many have been accompanied by wind and torrential rain as is normal, many have not ie. dry storms.
The other night we experienced around seven hours of continuous lightning and thunder.
So what causes this high-voltage show and how can you track where it’s happening?
Our Bureau of Meterology (BOM) says it begins within a developing thunder cloud.
Within the cloud there are millions of tiny ice crystals and super-cooled water droplets rubbing up against each other as they move up and down.
This causes a positive charge to develop at the top of the cloud and a negative charge at the bottom. The negative charge at the bottom of the cloud moves closer to the ground through a faint, negatively charged channel in a series of steps called ‘leaders’, while coming up from the ground are a series of positively charged channels known as ‘streamers’.
Photo: Maree Clout

When one of the positive steps connects with the negative streamer, a powerful electrical current races from the cloud to the ground, and this is when we see the lightning bolt.
Lightning heats the air around it to a temperature of approximately 30,000 °C, which is hotter than the surface of the sun. This rapid heating makes the air expand extremely quickly in a shock wave that we hear as thunder.
And how close is a lightning strike.
Count the number of seconds between the strike and the thunder and then divide by three. The result is the approximate number of kilometers (divide by 5 for miles).
Pretty scary as we have had lot of simultaneous lightning and thunder recently.
The amazing pic used in this post is by photographer Maree Clout. She has a Facebook site called Jervis Bay Through My Eyes which has some lovely photographs of our area.
This is the link: https://www.facebook.com/MareeCloutPhotography/