Canterbury thunderstorms 30 December 2009

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NZ Thunderstorm Soc
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Re: Canterbury thunderstorms 30 December 2009

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NZstorm wrote:Looks a weak set up tomorrow for Canterbury. Low level flow will be SW from early in the day which is not good. Pity as the upper air looks cold and I like the 60kt wind at 500mb. Another issue too would be the low tropopause height which has any convection that develops topping out under 6km. Well thats according to todays gfs run anyway. Best spot for storms looks offshore.
Thinking back of yesterday, this was probably the situ that caused the lack of thunderstorms. MetService has a good detector system thats why they picked up only the weakest of any thunderstorm attempt.I never picked up any sfericals whatsoever and the Steven Graham lightning detector only picked up one strike from what I saw.
There was the obviously instability but the persisitence of the SW from early morning ruined the chance of any development. Low cloud did look interesting, especially late afternoon as I did notice a very weak attempt of a funnel cloud formation about 5:45pm along the shingly bit of Finlays Road not far from here. Of course by the time the camera was ready to photo, it had gone.. There was a fine area to the south whilst TC kept on dishing out some occasional showers yesterday. When it eased there were castellatus forms which you associate for future thunderstorm development rather than dissipating, was happening before all cloud forms weakoned and it cleared up.