Possible Thunderstorms for the 17th of September

Tornado Tim · Unread post by **Tornado Tim** » Thu 17/09/2009 09:54

It seems a trough will pass over central North Island and with that some thunderstorms may occur.
M/S has updated there outlook to include Auckland and Eastern Waikato, less likely the the west however.
Here is Skew T for 2 PM, this this the time that seems to have the most action.
A 14Â°C DP, and a current temp of around 17-18Â°C will help with anything that forms.

DT-NZ · Unread post by **DT-NZ** » Thu 17/09/2009 10:18

Thanks Tim

Tornado Tim · Unread post by **Tornado Tim** » Thu 17/09/2009 12:32

It doesnt look good, looking at the sky anyway. Stable clouds... uh
Anyway today was out of the blue.

NZstorm · Unread post by **NZstorm** » Thu 17/09/2009 13:21

I think this type of situation in summer would be deeply convective but in September there is not quite the afternoon heating to generate the CAPE/sea breezes. The effective dewpoint is about 9C or 10C by the looks.

Todays midday sounding.

Tornado Tim · Unread post by **Tornado Tim** » Thu 17/09/2009 16:35

We have some action now, focus you eyes to the SW.
A very nice CB Calvus has passed the stable layer and just by looking at it you can see it grow!
It doesn't look that big in the pics but it is growing quite rapidly.
Update: Most of the convection has died

tgsnoopy · Unread post by **tgsnoopy** » Thu 17/09/2009 19:19

A couple of short sharp showers in the Papamoa/Te Puke area around 1pm, otherwise nothing much happened. Was quite a reasonable day otherwise.

Tornado Tim · Unread post by **Tornado Tim** » Thu 17/09/2009 19:36

um what are M/S on: http://www.metservice.co.nz/public/weat ... watch.html
They must have reason to issue this, but i dont see what the fuss is about.
For reference:

Myself · Unread post by **Myself** » Thu 17/09/2009 20:15

Tornado Tim wrote:um what are M/S on: http://www.metservice.co.nz/public/weat ... watch.html
They must have reason to issue this, but i dont see what the fuss is about.
For reference:

What did the text say? There were some impressive showers from inland Taranaki to the Central Plateau today....from about 3PM to 5PM but they fell right away after that.
http://www.metservice.com/public/maps/r ... 8-hrs.html
I wonder if they got worried because these showers started up mid afternoon, and the upper trough was still approaching. So the vorticity advection and cooling aloft could potentially have caused some greater action. I dunno really, just thinking aloud. Going from moderate risk of TS to issuing a severe TS watch can't be too common?

spwill · Unread post by **spwill** » Thu 17/09/2009 20:29

um what are M/S on: http://www.metservice.co.nz/public/weat ... watch.html
They must have reason to issue this, but i dont see what the fuss is about.

Stratford recieved 40mm in just 30 mins, this would have sparked the severe watch.

There was a thunderstorm over the southern NorthIsland high country .

Another dry day here with stable looking skies , radar showed isolated afternoon showers over Waikato as shown in your photos Tim

Nev · Unread post by **Nev** » Fri 18/09/2009 11:45

Nice funnel-pic snapped near Stratford yesterday in this story from the Taranaki Daily News...

'Another Taranaki twister?'

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Possible Thunderstorms for the 17th of September

Possible Thunderstorms for the 17th of September

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