Another bout of rain for the north

GreggWard · Unread post by **GreggWard** » Sat 07/08/2004 11:41

GraemeWi wrote:Came back from Wellington last night, was kind of hoping to get to see some of the front, but mostly a couple of flatish layers with some lumpy cu here and there. I suspect the other people on the flight - mostly grey / black suits - thought I was strange looking out the window the whole flight.

Cheers,

G

I'm glad someone else gets that feeling when they look out the window all the flight.

It's such a great vantage point.

Manukau heads obs · Sat 07/08/2004 11:42

getting some good lightning counts here

as CB pass by

GreggWard · Unread post by **GreggWard** » Sat 07/08/2004 11:49

Brian,

What type of lightning detector are you using to detect these counts? I would like to add a detector to my setup here at home.

Gregg

Willoughby · Unread post by **Willoughby** » Sat 07/08/2004 11:52

Aaron J Wilkinson wrote:Hmm, oh well. I looked at the data on the Metstrikeweb map and saw strikes close to Hamilton (it looks like it anyway).

See below, strikes in black boxed area near Hamilton occured yesterday during the morning sometime.

Black box is off Hamilton quite a bit, they must've hit around Matamata or Tirau...

Line of Cb's coming within the next hour or so, Hamilton's path! Looks like it might miss Ak city

NZstorm · Unread post by **NZstorm** » Sat 07/08/2004 11:55

Fairly unstable looking with a few strong looking buildups about the place.
There are cells coming off the sea in the westerly, but like yesterday, cells also developing locally from daytime heating. Lots of lower cumulus, so not so good for photography.

Manukau heads obs · Sat 07/08/2004 11:57

hi
see here
http://www.hobby-boards.com/

its for a dallas 1 wire setup
but i have it hooked up to a labjack.com
see the weather display forum about the wiring change needed to do that
its support in the weather display software, which now has MYSQL database direct updating added to it

GraemeWi · Unread post by **GraemeWi** » Sat 07/08/2004 12:53

Quite a few cbs around - mostly small and hitting us every 30 minutes or so with heavy showers. Photography not all that good due to lots of low cloud around. I managed these two earlier today before lunch.

G

Thunder · Unread post by **Thunder** » Sat 07/08/2004 13:10

Thanks Foggy, hopefully you get some storms today then!

Same to you NZstorm, conditions look good.

Great photos Graeme, I haven' t had that feeling for a while now when you see a big Cb infront of you, must be cool. Dam I need a thunderstorm!

Some more strikes have occured in the Waikato region during this morning at some point.

GreggWard · Unread post by **GreggWard** » Sat 07/08/2004 16:54

Manukau heads observer wrote:hi
see here
http://www.hobby-boards.com/

its for a dallas 1 wire setup
but i have it hooked up to a labjack.com
see the weather display forum about the wiring change needed to do that
its support in the weather display software, which now has MYSQL database direct updating added to it

Thanks Brian.

Gregg

GraemeWi · Unread post by **GraemeWi** » Sat 07/08/2004 17:30

The Cbs continued through the day - the wind is bitterly cold by Auckland standards.

Some more images from late afternoon.

Michael · Unread post by **Michael** » Sat 07/08/2004 18:27

A SW is always bitter and cold though its still westerly .Just dread the SW behind the front

GraemeWi wrote:The Cbs continued through the day - the wind is bitterly cold by Auckland standards.

Some more images from late afternoon.

NZstorm · Unread post by **NZstorm** » Sat 07/08/2004 19:21

The cb's were topping out at around 8000m today, which is certainly high enough for thunder. But CAPE (Convective available potential energy) was quite low, so updraughts within cb's don't get strong enough to provide sufficient electrification of the clouds. So plenty of cb showers but only Isolated weak storms.

another example of todays cb's.

NZstorm · Unread post by **NZstorm** » Sun 08/08/2004 08:21

Looks like another day of sunshine and showers for the north.
With the upper air a bit colder today, slightly higher chance of thunder than yesterday.

Manukau heads obs · Sun 08/08/2004 08:41

got some hail here a few minutes ago, and a lightning count

one big shower after another out to the west lining up!

GraemeWi · Unread post by **GraemeWi** » Sun 08/08/2004 09:22

We had some hail during the night, also some ultra heavy rain - it sounded like a bucket of water being tipped out on the roof. Some of the overnight Cbs were quite awesome to look at in the moonlight.

Quite a few Cbs out to the west of me now... so maybe today will be another 'interesting' day.

Cheers,

G

GreggWard · Unread post by **GreggWard** » Sun 08/08/2004 10:52

Nice clump of Cbs observed out to our W-NW about 30mins ago. Out to the NW getting dark now.

ricky · Unread post by **ricky** » Sun 08/08/2004 11:26

Just caught the edge of one passing to the southeast of here in grey lynn.. about 30seconds of very heavy rain with the odd 6mm hailstone thrown in just for fun

some good bursts of wind with the odd squall too..

Andy · Unread post by **Andy** » Sun 08/08/2004 11:50

Hey there Ricky

about 30seconds of very heavy rain with the odd 6mm hailstone thrown in just for fun some good bursts of wind with the odd squall too..

Any of that hail settle ?

Thunder · Unread post by **Thunder** » Sun 08/08/2004 11:58

Great photo Steven W

What would you say CAPE has to be at for thunder? Around 250-300 and higher I think seems right, would you concur with that?

spwill · Unread post by **spwill** » Sun 08/08/2004 12:01

In Queenstown.

The week I'm out of Auckland the Thundery Cbs arrive.

Very active Thundery weather south of Australia now should reach western parts of NZ in a day or two.

Cloudy and cool here with some light showers from DEAD Cb. Some light snow on the mnts this morning to 1200-1500m.

NZstorm · Unread post by **NZstorm** » Sun 08/08/2004 12:42

What would you say CAPE has to be at for thunder? Around 250-300 and higher I think seems right, would you concur with that?

Yes Aaron, so long as the convective parcel can lift to atleast 7000m level before it strikes the tropopause or some other very stable layer. And it helps if most of the CAPE is in the lower part of the atmosphere, so the rising convective parcel gets some good acceleration on it before it hits less buoyant air. If the low CAPE is evenly spread through the depth of the atmosphere, as it is here in Auckland today, the convective parcel never gets into an evironment where it can really accelerate and turn conditions thundery.

The higher the CAPE, the better, for thundery weather.

CAPE is increased in 3 ways, often a combination of,
Rising surface temperatures,
Rising surface humidity (dewpoint),
Cooling upper air (trough, cold pool, divergence....)

Thunder · Unread post by **Thunder** » Sun 08/08/2004 12:54

Thanks very much StevenW! I figured that number for thunder becasue earlier in February we had a storm on the Canterbury Plains that had CAPE values up to the 300 mark, it thundered that day out there but not much. Here's that map:

On another note, the guys on the weatherzone forums are suggesting with info the've collected from reports etc that it could well be an El Nino starting up with conditions neutral at present (between La Nina and El Nino). Apparently it's not good for Oz as it casues droughts, but, good for the east coast of the SI as far as thunderstorms are concerned. Maybe I should've started a new thread for this, quite interesting.

NZ Thunderstorm Soc · Sun 08/08/2004 13:05

Aaron J Wilkinson wrote:Thanks very much StevenW! I figured that number for thunder becasue earlier in February we had a storm on the Canterbury Plains that had CAPE values up to the 300 mark, it thundered that day out there but not much. Here's that map:

On another note, the guys on the weatherzone forums are suggesting with info the've collected from reports etc that it could well be an El Nino starting up with conditions neutral at present (between La Nina and El Nino). Apparently it's not good for Oz as it casues droughts, but, good for the east coast of the SI as far as thunderstorms are concerned. Maybe I should've started a new thread for this, quite interesting.

You may of done, AAron.
Whats the CAPE like for today because it you look out the window over the Port Hills NOW. there is some Cu devopment going on as I type $\:D/$

JohnGaul
NZTS

NZstorm · Unread post by **NZstorm** » Sun 08/08/2004 14:10

New Zealand has relatively poor sounding coverage, so the CAPE charts are just estimates or forecasts Aaron.

Photo taken in last hour. Glaciated cb without anvil out to east of here.