Canterbury thunderstorm photo

NZstorm · Unread post by **NZstorm** » Sun 08/05/2005 20:08

I stumbled across this excellent photo of a thunderstorm near Ashburton 31Oct 2003. Good example of cb with anvil.

http://www.lemurtech.com/essays/page.ph ... 3d43aced8a

Gary Roberts · Unread post by **Gary Roberts** » Sun 08/05/2005 20:45

NZstorm wrote:I stumbled across this excellent photo of a thunderstorm near Ashburton 31Oct 2003. Good example of cb with anvil.

http://www.lemurtech.com/essays/page.ph ... 3d43aced8a

See? I told you the mothership would be here anyday now!

NZ Thunderstorm Soc · Sun 08/05/2005 21:28

Excellent photo. Thanks Steven for coming across it.
I think Deano/Aaron had a report on it on our website?

JohnGaul
NZTS

Thunder · Unread post by **Thunder** » Sun 08/05/2005 22:02

Wow! What an awsome photo! I can see it has been blended from 2 or 3 images but apart from that awsome! I only hope I come across a storm like that to photograph!

Thanks very much Steven!

Here's a link to the landcare pic for that day but it's only at 10:29am (NZST) in the morning, can't find another for that day:

http://satellite.landcareresearch.co.nz ... d31103.jpg

What's your records say for this day John?

Actually we might have something in the archives of this forum about this day? Maybe, I'll just check...Ahh, here's a thread relating to that time:

http://www.weatherforum.org.nz/forum/vi ... 06&start=0

I've also just put together a sat image from the Modis archive, it was originally quite skewed like alot of them are. I've redone it to a resonable state, it's at 02 z, UTC, GMT on the 31/10/03. Not sure what time the people on the site took the photo, I guess sometime in the afternoon.

And below a pic I took from Wigram on the day of possibly the same cloud? Might be the Cb infront of the one they're taking a photo of, the Modis sat pic shows two Cb's. Not totally sure though.

I remember this day now! Ahh the excitment I had seeing all the Cb's! I didn't put a report on the site for this day John but will look into it.

Edit:

Just looked through the old thread from above and found all my old pics still there. Here's one:

Here's my caption for this pic back then:

This Cb looked huge! Almost supercellish, but I could'nt really tell from where I was. That bit of darkish cloud in the foreground of the picture annoys me a little as it obscures the front anvil of that big Cb.

And the thread / post part that went along with it:

http://www.weatherforum.org.nz/forum/vi ... c&start=15

Deano got some nice stuff to that day!

Cheers.

spwill · Unread post by **spwill** » Sun 08/05/2005 22:50

A great photo, thanks NZstorm.

Good to read about that day on the Forum archive, thanks Aaron.
Deano took some good photo's that day as well..

03Stormchaser · Unread post by **03Stormchaser** » Mon 09/05/2005 07:49

Having a problrem loading that photo?

comes up with:

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/lemurtec/public_html/essays/page.php on line 62

03Stormchaser · Unread post by **03Stormchaser** » Mon 09/05/2005 07:56

if anyone else is having trouble try this link:

http://www.lemurtech.com/essays/page.php?ID=2221

spwill · Unread post by **spwill** » Mon 09/05/2005 09:07

Looks like that photo has gone, good while it lasted.

Thunder · Unread post by **Thunder** » Mon 09/05/2005 09:27

Fear not.....

It's still there:

http://www.lemurtech.com/essays/page.php?ID=2221

That should work.

Edit:

hmm, it doesn't seem to work if you haven't got the page in your cache or something hence clicking on Steve's link above doesn't work. It will for me now though. Maybe try here then click on the photo?

http://www.lemurtech.com/essays/essay.php?Link=125

I also saved it last night to Gary, did you have to Print Screen SysRq it? I couldn't save it using the traditional method of 'right click' then 'save as'.

Edit again!

Oh well, saves perfectly fine using the traditional method in firefox but not in IE 6.0.

Cheers.

Gary Roberts · Unread post by **Gary Roberts** » Mon 09/05/2005 09:27

spwill wrote:Looks like that photo has gone, good while it lasted.

I saved a copy of that 'mothership cloud' photo. I have no idea who holds the legal rights to it, and whether I breached them by saving it! I can make the pic available from website, if somebody can clarify the legal side of things.

NZstorm · Unread post by **NZstorm** » Mon 09/05/2005 18:13

The owner of the photo is David at Lemurtech of Colorado.

I have emailed him and he has given me permission to use the photo.

I plan to put the picture up on my website.

03Stormchaser · Unread post by **03Stormchaser** » Mon 09/05/2005 18:49

did he have any others from that day?

NZstorm · Unread post by **NZstorm** » Mon 09/05/2005 19:47

He said the photo was taken near Mt Somers on highway 72 looking NE if anyone is interested in exact location.

Dean. · Unread post by **Dean.** » Mon 09/05/2005 20:57

Ahh brings back memories......
I followed that storm from State highway 72 near Mayfield all the way too Rakaia,an exciting day.I think Aaron may still have some video footage that I sent to him from that storm.
Looking forward to returning to the action in a couple of years,after I finish living in "Michaels" perfect climate world.

Cheers.

Thunder · Unread post by **Thunder** » Mon 09/05/2005 21:25

Thanks Steven for the location.

No I didn't get that tape off you Deano! do you still have it?

The ones I got off you were from a night time storm somewhere around the 5th of April 2004 out the back of Ashburton and another from another day but it wasn't that one (31st Oct 2003). So yeah, do you still have the vid from 31st Oct 2003?!

Cheers
Aaron Wilkinson

C-Nimbus · Unread post by **C-Nimbus** » Tue 10/05/2005 08:28

Thanks for the improved link Aaron, i finally managed to see the "Tropopause Puncher"

Its huge!!

The texture in the anvil actually reminds me of NZstorm's Canterbury Cb photos with the F/C....

Tis all good stuff

Dean. · Unread post by **Dean.** » Tue 10/05/2005 16:14

I still have the tape Aaron,but it is tucked away in storage back home.

Thunder · Unread post by **Thunder** » Tue 10/05/2005 16:17

Cool. See ya when you get back then.

Cheers.

Thunder · Unread post by **Thunder** » Tue 10/05/2005 22:25

Skew t for the day in question, modeled of course. I've done it so it was close to Mt somers (not the mountain itself) and I've got the Temp and dewpoint starting at the 964mb line as to represent the height involved when you go inland.

Quite nice with -6 Li's! As for CAPE, I'm not sure. At a guess somewhere around 1500, maybe more. Anyone want to guess? I don't know how to work it out the proper way, all I know is 'yes it's unstable!" or it's a little unstable etc etc.

Cheers.

NZstorm · Unread post by **NZstorm** » Wed 11/05/2005 06:45

I had a look at the Invercargill sounding and it matchs this one well. Ofcoarse this model would have been built on the Invercargill data anyway. Good potential instability showing up on the skew-t. There would have been a good convergence line to trigger that type of convection. The Canterbury northeaster would have been runnning nicely into a trough backed up by a westerly quarter wind change. And looking at those upper temperatures there would have been some hail in there, although non was reported, it would have certainly been there.

A similar situation I would say to what I observed on Boxing Day last year in South Canterbury. Makes for good photography.

Thunder · Unread post by **Thunder** » Wed 11/05/2005 09:37

Where do you get the archived skew-t data Steven? Someone put up a link before but I can't remember it, and station number for Invercargill if you can. I understand you don't use the NZNV type system, it's a number but I'm not sure which.

The modeled sounding is an archive of modeled data which the model makes (would've been the latest run up to the time in question I believe), I don't think it's based on what actual skew-t's were like. I ploted it at -43.9 171 which is ruffly near Mt Somers. Given that it is a 120Km resolution model (GFS that is) I believe some data wouldn't be that far off what the Invercargill skewt for that day suggests, it does intorpolate information between each point so it's not acurate in those areas but seems to do ok.

I got the surface temps and dewpoints from the nrfa.org.nz archive at Mt Somers. This map shows variable winds in that area for the day so a convergence is what look like did it:

Cheers.

Edit: Sorry I found the link from the soundings post, doh! If you have the Invercargill code that would be great though, I should be able to find it though.

NZstorm · Unread post by **NZstorm** » Wed 11/05/2005 10:20

Invercargill is 93844

Both NZNV and 93844 usually work.

Interesting chart Aaron.

Thunder · Unread post by **Thunder** » Wed 11/05/2005 10:42

Cool! Thanks very much Steven.

Looking at the archived upper air map the Invercargill Skew-t would actually be very similar to the modeled one above as the upper cold pool was about the same temp from Canterbury down to Otago that day. Some nice instability!

These westerly / NE convergences, are they what you would call a 'dry line' type storm? Like the one you got near Timaru. I've never really thought too much about those type of storms in Canterbury, usually when there's a NW floating around out there you tend to think it's all over due to it drying everything out. I guess it depends on how strong the NE is up against the NW? I don't think it would happen when you've got a lee trough NE and NW inland due to the isobars crunching up against the alps, it just seems to be the positioning of lows when they float across and provided the upper air is cold enough something can form I guess? Included is the 1pm BoM MSLP chart for the day in question.

NZstorm · Unread post by **NZstorm** » Wed 11/05/2005 18:03

These westerly / NE convergences, are they what you would call a 'dry line' type storm?

Yes, I think there could be an element of the 'dry line phenomena' in them. The Boxing Day storm was preceded by dewpoints of 12C and followed by dewpoints 4C.

Thunder · Unread post by **Thunder** » Wed 11/05/2005 21:33

Just having a look back through my pics, I've been through two of these dry line type ones come to think of it. With the first one a good thunderstorm formed but quickly went offshore and me and Steven Graham only got to see a little of it as it went by quickly. That was on the 21st December 2004. We got to see another Cb form which it then went into a small storm with 5 or 6 lightning flashes and then it dissapated only giving very brief rain. Isobar map for this day at 1pm attached.

The second was on the 7th Jan 2005. There was some initial development that looked good near Glentunnel and it went to a small Cb but then dissapated giving not much rain at all. Picture below.

Another two nice looking clouds formed but they didn't get anywhere, one of which is in that photo comp, this one:

http://www.weatherforum.org.nz/forum/do ... hp?id=1019

Looking at the first situation wunderground shows that at 2pm/3pm the dewpoint went from 12 C to 4C so that shows the NW finally coming through, so yes I think this was a dryline type one.

Then with the second situation (7th Jan 05) the NE stuck around at the NZCH AWS, but here:

http://www.nrfa.org.nz/fire_weather/wea ... 050107.jpg

you can see that it was NW inland which it was when I was out there.

I think in the first instance there was too much mixing of the air after the first storm at the surface resulting in lower dewpoints than what the NZCH AWS said of 12 C, the representation in terms of instability could've been only around 8 or 9 C? Upper cold air could've been another factor in terms of it not being cold enough but I think it was ok, the thunderstorm in the morning showed that. The second storm that was weak (will post pic tomorrow) was so I think because of the lower moisture at the surface overall. In the second situation there was a lack of cold upper air as the NE was doing well so there would've been a good boundry there, just no instability in the upper levels to support it.

There was great storms in Otago on the 7th Jan formed by the same dryline principal but upper air was colder so storms formed much better!

I got caught out on the day of that Timaru funnel NZstorm so now I know this stuff I'll know for next time!

Bahh! I rambling on but find it fun to learn about this stuff!

Cheers.

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Canterbury thunderstorm photo

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