End of week bitterly cold outbreak

Michael · Unread post by **Michael** » Wed 02/07/2003 23:26

What is needed is a large high over the lower half of the south Is and a low just to the east of NZ with a warm front over the country being uplifted by cold air like the event in 1973

NZstorm · Unread post by **NZstorm** » Thu 03/07/2003 06:51

Re the warm advection snow storms

Just looking at snow storms in the Dunedin area, nearly all of these have been the cold advective type. The cold air is deeply unstable with tops above 5000m. Mesoscale disturbances within the flow enhance the precipitation. Dunedin and South Otago/Southland get most if not all their snow falls from this type of situation.

For Canterbury the warm advective snow storm is the one that brings the prolonged heavy falls. But I agree with Tich, it is more an inland phenomena and unforetunately quite rare. The big snow falls of past years in Central Otago have been classic warm advection storms.

Good point about the PW Tony. In the subantartic islands it does tend to be extremely low. I noticed MacQuarie island had an air temp of -3C but dewpiont was -10C the other morning. Dewpionts tend to get higher as the air moves north. Will watch with interest.

NZstorm · Unread post by **NZstorm** » Thu 03/07/2003 07:05

This mornings satellite picture shows lots of cb's out to the SE

Andy · Unread post by **Andy** » Thu 03/07/2003 10:10

Re the warm advection snow storms

Interesting reading cheers guys

Chris Raine · Unread post by **Chris Raine** » Thu 03/07/2003 11:17

The Cb's in Invercargill appear to have more depth to them than the ones I saw yesterday. Temp was 6 degrees at 0900 obs and falling. Gusty westerly .Having frequent showers. Waiting with baited breath for the "mother of all southerly outbreaks" It like waiting for a plane to land at the airport.

Michael · Unread post by **Michael** » Thu 03/07/2003 11:55

Its very cold and overcast in Auckland today but still "dry" and no wind to speak of

Andy · Unread post by **Andy** » Thu 03/07/2003 18:39

mild today with clear skies and a westerly breeze

max today 12.4

Current temp 6.8

Prseeure 996mb and steady

NZstorm · Unread post by **NZstorm** » Thu 03/07/2003 21:52

A very weak cold front crossing Southland this evening. Will bring a sharp drop in the freezing level with its passage but looks to be more of a surface change. I know this by the depth of the cloud, no higher than about 2500m. I suugest this front is only the curtain-raiser and hopefully something a bit more active comes up tomorrow. (deeper cold change).
Will watch with interest. I'm hoping for a big snow dump over the central NI so i can go skiing.

Dean. · Unread post by **Dean.** » Thu 03/07/2003 22:31

Yes Im hoping this polar blast comes off.
I have talked my brother into travelling up from Dunedin tonight instead of Friday night due to the forecast,he wasnt too happy about it,hopefully I will be the one telling him I told you so this time tommorrow!!!.
Cheers.

NZstorm · Unread post by **NZstorm** » Fri 04/07/2003 07:05

More active cb's are now moving onto southern NZ this morning.
Last nights weak front lowered the freezing level at Invercargill to 947hpa which is around the 400m level, this next change should lower it further.

Deano, the road between Milton and Lawerence will catch some snow today. I would'nt expect much snow in Central Otago though as it is quite sheltered.

Dean. · Unread post by **Dean.** » Fri 04/07/2003 07:41

Current conditions steady rain 3 degrees with a hint of sleet.
Reports of snowing in Methven,Geraldine.
Rain started about 6.15am.
Cheers.

NZstorm · Unread post by **NZstorm** » Fri 04/07/2003 07:44

Weather should get really interesting this afternoon Deano when the bigger cb's arrive. The cold outbreak looking quite active over Southland this morning.

Manukau heads obs · Fri 04/07/2003 07:51

http://www.hpca.co.nz/homeweather.htm

a new web site i found, Masterton
teh web cam will be interesting....
and we wil be able to watch aas the southerly arrives (but i see they had a frost this morning for starters)

Dean. · Unread post by **Dean.** » Fri 04/07/2003 07:59

Yeah,seems to be two fronts Steven,the first SSW over Canterbury at the moment,and the colder southerly touching Southland now.
Cheers.

Manukau heads obs · Fri 04/07/2003 08:15

http://homepages.ihug.co.nz/~Shardie/we ... eather.htm

bluff weather as it happens....currenty only 2oC, wind still westerly

Andy · Unread post by **Andy** » Fri 04/07/2003 08:32

Snow all around as at the moment - Queenstown, Wanaka Cromwell.
Clearing skies at the moment to the south, with no rain overnite.

Temp is still dropping was 0 degrees at 8:00
Now -0.6, pressure 996mb

tich · Unread post by **tich** » Fri 04/07/2003 08:51

Still dry in central Christchurch, though it has clouded over this morning. The wintry precipitation is expected to arrive any moment soon. Already heard reports of snow in Timaru, and the the coldest air hasn't even reached the South Island yet. The rain (and snow) in inland Canterbury could be pre-frontal. It was already cold overnight - another frost in Christchurch, and a weak front seems to have kickstarted southerlies for the region later in the night.

Ben
Christchurch

Chris Raine · Unread post by **Chris Raine** » Fri 04/07/2003 09:34

In Invercargill from last evening we had some sleety showers and small hail with the weak front that Steven describes. Following that wind dropped temp went down to 3.5 degrees. This morning at 6am was partly cloudy and 2 degrees. By 0900 obs was snowing lightly with showers of snow pellets and settling . Roads are becoming icy and some minor accidents are being reported. Temp was down to 1.6 degrees with a dew point of -0.6. Wind SWof 2-3 kts. Think there is more to come from looking at the 2100GMT satellite picture. Could be an interesting day.

tich · Unread post by **tich** » Fri 04/07/2003 09:45

Started drizzling shortly after my last post and soon turned to rain. Only liquid stuff so far in the city (it's about 3 or 4C), but I'd guess it's probably snowing on the Port Hills and Banks Peninsula.

Ben
Christchurch

Andy · Unread post by **Andy** » Fri 04/07/2003 10:00

Clearing skies here in Alexandra at the moment to the south, with no rain overnite.

Temp is still dropping was 0 degrees at 8:00
Now -0.6, at 10:00 with some coud and blue sky there is cold southerly breeze and it is ment to get even colder....

pressure 996mb

has been snowing in Queenstown, Wanaka, Cromwell, Invercargil, kingston - and many other parts, chains are require on most inland rds

Chris Raine · Unread post by **Chris Raine** » Fri 04/07/2003 10:20

It has been snowing steadily all morning .We have a gentle SW with 1 cm of snow lying.

Dean. · Unread post by **Dean.** » Fri 04/07/2003 10:21

Snowing now in Ashburton,temperature has dropped steadily since 6.30.
Reports of snow settling in Timaru.
Cheers.

.

Michael · Unread post by **Michael** » Fri 04/07/2003 10:51

Your weather is quite exciting 20 degrees in winter one day the next snowing, the next clear and sunny,next interesting wave cloud and cirrus-Ours is drab Southwesterlies cloudy and wet days on end

Dean. · Unread post by **Dean.** » Fri 04/07/2003 11:34

1-2 cm on the ground already,the roads are becoming very dicey.
Im picking snow to sea level in Wellington tonight.

Andy · Unread post by **Andy** » Fri 04/07/2003 11:50

The mother of cold snaps...

hehe clear calm with blue sky and 2 degrees