"Big Blow" Celebrations

NZ Thunderstorm Soc · Sun 31/07/2005 22:11

Read my tribute to the "Big Blow" celebration on the Weather Observations site.
30 years to the day.
No NW in sight tho' tomorrow just a tame SW change

JohnGaul
NZTS

NZ Thunderstorm Soc · Sun 31/07/2005 22:40

Here it is here:

Tomorrow(August 1st)is the 30th anniverary of the "Big Blow" here in Canterbury where hurricane force NW winds destroyed many trees here in Canterbury including the Balmoral Forest where many trees were flattened.
From Otago to Waiararapa on the morning of August 1st 1975, unusually strong NW winds struck eastern distrcts of NZ
I was travelling north from Timaru on a goods trains and the strength of the wind kept the Dj struggling north from Temuka with a load of 900tons at a low speed. We got as far as Hinds and we couldn't go any further.
there was debris everywhere. The wind was that strong at Hinds I couldn't get out of the door on the LA's side.
We waited there until the winds sudsided and then a taxi took us home.
There was mess everywhere mainly from trees but we mangaged to get back to Christchurch.
The highlight of the storm was seeing the wheat silo rolling through the paddock whilst the wind was blowing strongly near Orari
According to records, gust reached 105 knots on the Kaikoura Peninsula,Eyrewell Forest 92 knots,Christchurch Airport 93 knots, Wigram 84 knots,Winchmore 82 knots, MtJohn, 104knots, Levels airport near Washdyke,89 knots,Queenstown 84 knots, Taiaroa Heads 94 knots Momona International airport 82 knots and Invercargill Aerodrome 71 knots.
Widespread damage resulted with large areas of forest devasted.Lots of roofs were blown off and entire buildings demomlished.
In the upper Selwyn River area, 7 power pylons came down.
The winds were caused by belt of high pressure lying across from a high to the NE of the country being squeezed by a TC way toi the north of NZ
To the south an active cold front was making it's way across the sth Tasman Sea. The angling of the isobars resulted in a high different pressure difference (between 15 to 25 hPas) between west and east coasts. Whilst winds on the West Coast were only averaging about gale force (34 knots) it was because of the uplifting affect of the Southern Alps that winds on the East Coast were up to destuctive/hurricane force speeds in the early hours of August 1st 1975

JohnGaul
NZTS

Andy · Unread post by **Andy** » Mon 01/08/2005 06:57

Nice stuff

Thunder · Unread post by **Thunder** » Mon 01/08/2005 13:28

Thanks for the info John, a good read.

Gary Roberts · Unread post by **Gary Roberts** » Mon 01/08/2005 17:41

NZ Thunderstorm Soc wrote:Here it is here:

Tomorrow(August 1st)is the 30th anniverary of the "Big Blow" here in Canterbury where hurricane force NW winds destroyed many trees here in Canterbury including the Balmoral Forest where many trees were flattened.
From Otago to Waiararapa on the morning of August 1st 1975, unusually strong NW winds struck eastern distrcts of NZ
I was travelling north from Timaru on a goods trains and the strength of the wind kept the Dj struggling north from Temuka with a load of 900tons at a low speed. We got as far as Hinds and we couldn't go any further.
there was debris everywhere. The wind was that strong at Hinds I couldn't get out of the door on the LA's side.
We waited there until the winds sudsided and then a taxi took us home.
There was mess everywhere mainly from trees but we mangaged to get back to Christchurch.
The highlight of the storm was seeing the wheat silo rolling through the paddock whilst the wind was blowing strongly near Orari
According to records, gust reached 105 knots on the Kaikoura Peninsula,Eyrewell Forest 92 knots,Christchurch Airport 93 knots, Wigram 84 knots,Winchmore 82 knots, MtJohn, 104knots, Levels airport near Washdyke,89 knots,Queenstown 84 knots, Taiaroa Heads 94 knots Momona International airport 82 knots and Invercargill Aerodrome 71 knots.
Widespread damage resulted with large areas of forest devasted.Lots of roofs were blown off and entire buildings demomlished.
In the upper Selwyn River area, 7 power pylons came down.
The winds were caused by belt of high pressure lying across from a high to the NE of the country being squeezed by a TC way toi the north of NZ
To the south an active cold front was making it's way across the sth Tasman Sea. The angling of the isobars resulted in a high different pressure difference (between 15 to 25 hPas) between west and east coasts. Whilst winds on the West Coast were only averaging about gale force (34 knots) it was because of the uplifting affect of the Southern Alps that winds on the East Coast were up to destuctive/hurricane force speeds in the early hours of August 1st 1975

JohnGaul
NZTS

Was that an election year by any chance?

Michael · Unread post by **Michael** » Mon 01/08/2005 19:14

Yes it was Labour was in then at the time

Gary Roberts wrote:
NZ Thunderstorm Soc wrote: Was that an election year by any chance?

as far as the event its recorded in the 1978 BCNZ book

NZstorm · Unread post by **NZstorm** » Mon 01/08/2005 19:23

Thanks for that interesting report John. Interesting that this big NW blow occured in winter (1 Aug), you would expect that kind of storm later in spring. I doubt there has been a comparable NW'ester since.

NZ Thunderstorm Soc · Mon 01/08/2005 23:03

NZstorm wrote: I doubt there has been a comparable NW'ester since.

not to my knowledge although there have been other NW wind events but nothing as signifcant as this particular event.

JohnGaul
NZTS

NZstorm · Unread post by **NZstorm** » Tue 02/08/2005 07:41

The Insurance council say the damage bill for that storm was $7 million in 1975 which equates to $57 million in todays dollars. One of the more costly weather disasters in NZ history.

Fujita Phil · Unread post by **Fujita Phil** » Tue 02/08/2005 14:44

I always remember my Dad telling me about this "wind" event he witnessed once many years ago. As they raced down the valley from the Haka towards Oamaru the winds were so strong they watched pylons crumble in the wind. He said it then all of a sudden just became calm, which he reckoned was more terrifying and they raced back home in case it started again.

I'll check with him and ask if in was 75'.

NZ Thunderstorm Soc · Tue 02/08/2005 23:22

Fujita Phil wrote:I always remember my Dad telling me about this "wind" event he witnessed once many years ago. As they raced down the valley from the Haka towards Oamaru the winds were so strong they watched pylons crumble in the wind. He said it then all of a sudden just became calm, which he reckoned was more terrifying and they raced back home in case it started again.

I'll check with him and ask if in was 75'.

It was probably the same storm.
I remember heading south on train No 123 I think it was, noticing how exceptionally electrically active the Southern Alps were that evening prior to the wind onslaught.
I can't remember anything more since then.
JohnGaul
NZTS

tich · Unread post by **tich** » Wed 03/08/2005 21:05

not to my knowledge although there have been other NW wind events but nothing as signifcant as this particular event.

A Canterbury northwesterly storm in October 1988 (I wasn't there to witness it) was compared to the 1975 one - it also made the existing drought there far worse. (probably the area's worst drought in recent history - not relieved until April 1989)

MetService has issued a number of warnings about severe northwesterlies predicted for Canterbury in recent years, but luckily the winds hasn't turned out as bad as forecast. (at least for here)