NZ Weather Forum

Off on a light tangent, what do we think folks- I'm picking some lively discussion onm the matter! I have seen clouds like this in Fiordland and over on the West Coast quite regularly

http://www.odt.co.nz/news/world/60876/u ... e-cloud039

Looks like mattamus with rain behind it.

looks like a grouped together bunch of kelvin waves ?
there was a post here recently about gravity wave clouds....this looks similar to those too

Looks like startocumulus. Obviously a bit sculptured but this type of stratocu is already well documented.

We get clouds like that all the time here in Canty too...especially if there is a really well defined NW arch...what may have thrown that lady is the fact that the clouds were undulating so rapidly?

Looks very turbulent....It doesnt look new however to me.

I think it is the base of Cumulus cloud on a wind change, the wind change already through.

Further to what glitz said, Bob McDavitt wrote a Blog post about it:

http://blog.metservice.com/pages/asperatus/

He also links Asperatus to the NW Arch

I think the cloud in question is fairly low based, I'm thinking between 2 and 4000ft so I've labeled it a form of stratocumulus but it could be the base of a cumulus I guess. The NW arch is very elevated, normally around 20,000feet.

I would say the light/dark is caused by big changes in the height of the cloud above (i.e more/less shadow)
and also the sun position/angle would need to be such to show this up more
(a bit like how the setting sun makes the underside of jet stream cloud reveal its detail)

Isn't the idea that asperatus could be tagged onto a cloud of any height though. Doesn't matter whether it's low, mid or high just so long as it's undulating. I guess you could have Stratocumulus Asperatus, and Altocumulus Asperatus.
Dunno...I'm not really into cloud names, it's just a form of book-keeping to my mind and barely even a lick on the science of meteorology.

Iowa is generally flatt country.
I think we are looking at the back end of a Gust Front, Cu or Cb over head, skies about to clear.

Was on wattsupwiththat.com a couple of weeks ago, assuming it's the same thing. An especially stunning photo here:

http://chattahbox.com/images/2009/05/as ... _cloud.jpg

Cloud classification I think is fine, but it can hardly be called 'scientifically rigourous'.

I'm into naming things and I think that Bob McDavitt's name would be the best for that cloud form.
but then....
I would of thought of a more scrumptuous name like 'wringer' cloud may do as the look like sheets being wringed out

JohnGaul
NZThS

Well done guys!

http://www.news.com.au/couriermail/stor ... 16,00.html

I know Matt Pearce personally.. take it all with a grain of salt.
Havent laughed so hard in a long time however

NZ Thunderstorm Soc wrote:I'm into naming things and I think that Bob McDavitt's name would be the best for that cloud form.

JohnGaul
NZThS

A cloud called Bob McDavitt??? Lol