"Hell to Pay" - polar blast even worse than it was

tich · Unread post by **tich** » Fri 11/07/2003 20:27

I remember someone from MetService last wekend saying that if the complex low pressure system was still over the North Island when the freezing southerly blast of Saturday, there would be "hell to pay" from Canterbury to Gisborne. Well, in the east of the North Island was savagely battered anyway, so it's difficult to imagine the system being even worse than it was.

But imagine if it was. How big a civil defence emergency would it be? Perhaps the heavy snow would be even more extensive. Last Saturday, the snow fell to low levels about and south of Taranaki and the central plateau, as well as the east of the North Island, but not further north. But imagine the effect of heavy snow in places like the South Waikato, Taupo, and Rotorua areas. I could imagine roads like State Highway 5 between Rotorua and Taupo and across the Mamaku plateau being closed. People wouldn't be used to it, and I could imagine many stranded motorists. (even in the recent blast, people weren't expecting such a vicious snowstorm in Hawkes Bay - no wonder so many drivers had to be rescued)

Ben
Christchurch

Manukau heads obs · Fri 11/07/2003 21:36

its hailing and raining real hard here at the moment!!!!!!!!!!!!!

Michael · Unread post by **Michael** » Sat 12/07/2003 08:18

I don't think we had any precipitation overnight here and better still it looks like the sun may be out today

Manukau heads obs · Sat 12/07/2003 15:58

there is a very impressive line of CB's in the SE to the NE of the upper NI, nd into northland
any pictures from anyone?
( i can see the tops from here, they look amazing)

Thunder · Unread post by **Thunder** » Sat 12/07/2003 17:10

Yes, has anyone got Photos! Cool picture GraemeWi on the other thread of the Cb!

Cheers
Aaron Wilkinson

NZstorm · Unread post by **NZstorm** » Sat 12/07/2003 17:18

Cb's out to the north have looked impressive today despite their distance.
Quite cold unstable air over that region with the freezing level around 1500m. And with sea surface temperatures around 18C, its not suprising there are some good cb's.

tich · Unread post by **tich** » Sat 12/07/2003 22:18

Cb's out to the north have looked impressive today despite their distance.
Quite cold unstable air over that region with the freezing level around 1500m.

I'm curious to know where you get the freezing levels you often mention. Are they taken from a free public-access website, or from estimates taken from thickness levels? BTW do you remember what the freezing levels were for the North Island (especially the north) during last Saturday's icy blast?

Ben
Christchurch

NZstorm · Unread post by **NZstorm** » Sun 13/07/2003 10:19

Ben,
I use the upper air soundings to estimate the freezing levels. As there are only three upper air stations for temperature in NZ, one has to fill in the gaps with an educated guess.

Go to this website(one of the most useful weather sites on the net)

http://weather.admin.niu.edu/machine/sound.html

Select one of the two observation times 00Z/12Z
Select skew-t
Type in four station digit code nzwp(AK), nzpp(wn) nznv(Invercargill)
Enter and you have the latest skew-t. Heights are marked on the left side of the skew-t.

Skew-t are excellent for getting a feel of an airmass, estimating convection heights....predicting thunderstorms.

Other useful upper air stations for NZ
ysnf (Norfolk island)
nzri(Kermedec Islands)
ymmq (Maquarie island)
ymhb (Hobart)

Cheers

NZstorm · Unread post by **NZstorm** » Sun 13/07/2003 10:23

And this URL also provide the latest skew-t.

There is an archive of NZ upper air soundings on here back to about 1995.

http://weather.uwyo.edu/upperair/sounding.html

For the region select South Pacific(not NZ)
Be sure to select skew-t also.

NZstorm · Unread post by **NZstorm** » Sun 13/07/2003 10:45

Snow watchers might find this URL of interest for checking out snow levels in the Central NI. They actually make great weather cams.

http://www.geonet.org.nz/volcanocam.htm