Storm Australian Severe Weather Forum

Severe Weather Discussion => General Weather - all topics not current severe weather. => Topic started by: Shaun Galman on 10 November 2007, 04:35:02 PM

Title: Does Crawler Lightning become more active in colder atmospheric conditions?
Post by: Shaun Galman on 10 November 2007, 04:35:02 PM

Hi guys,
This is something that I thought was worthy of a thread topic. I have noticed in many "atmospherically colder" storms that crawler lightning tends to become more active than CG. I have seen a few cells exhibit these characteristics over the years, particularly in the dying stages where temperature cooling has caused, not so much a weakening in activity, but a weakening in CG activity and seeing crawlers becoming predominant.

My thoughts were, that it may be due to a collapse in the upper structure of the storm with colder inflow stopping the updraft and bringing upper (anvil) and lower levels closer and reducing the charge capacity low enough to stop cloud-ground arcing? Can the storm itself cause it's own demise by lowering the surrounding temperatures?

The recent storms we had showed this particularly well, with highly active CG as the storms approached in the afternoon (with temps in the low 30's) and with the obvious falling temperatures (down to 18degrees or so) we saw nothing but crawler activity until the storms had depleted.

Perhaps you have seen or noticed something similar, so any discussion and thoughts put forward are much appreciated :)
Regards and take care.
Shauno
   

Title: Re: Does Crawler Lightning become more active in colder atmospheric conditions?
Post by: Richary on 10 November 2007, 05:25:36 PM

Brings to mind one I saw in Lismore in the early/mid 80s. Too long ago to remember what time of year it was. This lightning launched from one point and just kept spreading out across half the sky like tree branches splitting off. Now that one would have made an absolutely awesome photo. Never seen anything quite as spectacular, though the ground strikes have their advantages as well.

Title: Re: Does Crawler Lightning become more active in colder atmospheric conditions?
Post by: Jimmy Deguara on 11 November 2007, 03:49:05 AM

To my knowledge,

The concept if anvil crawlers tend to related to weakening thunderstorms. In other words, there is a lack of ability to produce discharged grounded strikes.

I guess it is the complementary prize given it is weakening overall.

Regards,

Jimmy Deguara