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Re: T-storms risk - Sat 22 Nov

Posted: Mon 24/11/2014 15:42
by Manukau heads obs
there was thunderstorms just to the south of CHCH in the afternoon (that headed out to sea)

Re: T-storms risk - Sat 22 Nov

Posted: Mon 24/11/2014 20:37
by NZstorm
Manukau heads obs wrote:there was thunderstorms just to the south of CHCH in the afternoon (that headed out to sea)
There was an elevated storm scenario over South Canterbury, convection initiating at 2500m. Elevated storms don't typically do not produce severe weather unless it is an excessive rainfall scenario.

Re: T-storms risk - Sat 22 Nov

Posted: Tue 25/11/2014 00:23
by Chris Raine
Don't know what I drove through at Arundel on the Inland route , the rain was torrential , big hail and decent lightning and thunder . I was at Mayfield and my lightning tracker said activity 25km SW so I drove in that direction and found the storm . I could see the storm building to the west with a developing anvil behind the Peel Forest area

Re: T-storms risk - Sat 22 Nov

Posted: Tue 25/11/2014 06:15
by Nev
Thanks for the reports Chris. For want of some better images, I grabbed these radar-images from TVNZ. The first image at very roughly about 2pm shows the northern cell that you probably drove through. And the second image about an hour or two later shows just how much the storms flared-up after moving out to sea.
Chch radar ℅ TVNZ - Nov 22, approx 2pm.jpg
Chch radar ℅ TVNZ - Nov 22, approx 4pm.jpg

Re: T-storms risk - Sat 22 Nov

Posted: Tue 25/11/2014 06:57
by NZstorm
Chris Raine wrote:Don't know what I drove through at Arundel on the Inland route , the rain was torrential , big hail and decent lightning and thunder . I was at Mayfield and my lightning tracker said activity 25km SW so I drove in that direction and found the storm . I could see the storm building to the west with a developing anvil behind the Peel Forest area
Every thunderstorm is severe its own way but when I talk about severe weather, I am referring to the meteorologists definition of severe weather. 20mm+hail, persistent rain to cause flooding.

Re: T-storms risk - Sat 22 Nov

Posted: Tue 25/11/2014 08:58
by spwill
Metservice had a high thunderstorm risk/severe thunderstorm watch with the southerly wind change where nothing developed.