Awesome jetstream clouds - overhead now

C-Nimbus · Unread post by **C-Nimbus** » Thu 03/03/2005 15:35

If your in aucks, look up NOW to see a perfect jetstream.

All the cirro-forms seem to be represented!

Michael · Unread post by **Michael** » Thu 03/03/2005 17:34

Its now getting Black with the SW constantly rising.The map shows the front in Taranaki now

GraemeWi · Unread post by **GraemeWi** » Thu 03/03/2005 20:09

03Stormchaser · Unread post by **03Stormchaser** » Thu 03/03/2005 20:22

sorry for my ignorance but what is a jetstream?? cant say ive seen any in chch!

GraemeWi · Unread post by **GraemeWi** » Thu 03/03/2005 20:38

03 Stormchaser wrote:sorry for my ignorance but what is a jetstream?? cant say ive seen any in chch!

Basically high altitude winds in a narrow band, like a river almost...

http://www.bbc.co.uk/weather/features/a ... et28.shtml
http://www.bbc.co.uk/weather/features/a ... et29.shtml

Cheers,

G

Willoughby · Unread post by **Willoughby** » Thu 03/03/2005 20:50

Here we see the Jetstream postions for Aus-NZ currently

Manukau heads obs · Thu 03/03/2005 21:18

there was the remains of a weak front moving over the NI today.,,,,,,with just high cloud left over....which was moving down from the NW...but it was not moving all that fast, not like high cloud associated with a stream can

Manukau heads obs · Thu 03/03/2005 21:19

there was the remains of a weak front moving over the NI today.,,,,,,with just high cloud left over....which was moving down from the NW...but it was not moving all that fast, not like high cloud associated with a stream can

C-Nimbus · Unread post by **C-Nimbus** » Fri 04/03/2005 08:09

03 Stormchaser wrote:sorry for my ignorance but what is a jetstream?? cant say ive seen any in chch!

I was always told to look at a Jetstream as the steering mechanism for our weather. All our weather (well most of it anyways) comes in from the west, and the alternating highs and lows are simply carried underneath the jetsream.

If the earth didn't rotate (NZ btw rotates at about 850km/h) warm air from the tropics would simply move to the poles to equalise temps (ie temp gradient). But because the earth spins air movements are sheared in such a way that the earths rotation causes them to move from W-E, this is due to coriolis,

well thats my take on it anyway.

So GraemeWi, in your opinion was this not a jet stream cloud? I just assumed it was because of its orientation/height etc.

Heres one for the buffs.....

Describe what the Eckman Spiral is?

Manukau heads obs · Fri 04/03/2005 08:19

my 2 cents worth:
it was just some cirrus left over from the weakening front....but that cirrus was there also as a result of a relatively weak stream across across the tasman....its bit the chicken or the egg

a real good big fast jet stream can produce a very wide nicely curving cirrus cloud with a very marked edge to it.....and it moves really fast when you watch it....over 100kts it can go at...

still, great photo though

C-Nimbus · Unread post by **C-Nimbus** » Fri 04/03/2005 08:31

Manukau heads observer wrote:my 2 cents worth:
it was just some cirrus left over from the weakening front....but that cirrus was there also as a result of a relatively weak stream across across the tasman....its bit the chicken or the egg

reminds me....which came first, the chicken or the egg.....neither, it was the rooster