NZ Weather Forum

The Southern Oscillation Index has jumped considerably now at the end of September to 25.8 - which is the highest monthly reading since November 1973 and highest September reading since 1918!

We all know how Australia feared in 1974 and the effects of it then... was NZ similar at all? What also happened in 1955/56?

Look at how cold the upper-level equatorial Pacific has been getting... That cooler than normal water of -6C at 100m should rise.


Interesting season ahead!!

We all know how Australia feared in 1974 and the effects of it then... was NZ similar at all? What also happened in 1955/56?

I think 1956 was Auckland's wettest year on record (over 2000mm)

Would be interesting if that happened again, LOL

Expecting a cloudy and very humid summer here in Auckland with perhaps an early start to summer. North and Eastern parts of the country will probably see more cloud and rain than normal this summer due to more easterly quarter flows.


Niwa outlook Oct- Dec http://www.niwa.co.nz/our-science/clima ... t-dec-2010

You have to be careful with single-month SOIs. The NOAA ONI index, which uses 3-monthly means of a value based on SST anomalies in Nino 3.4, will probably be a better indicator of ongoing strength.

http://www.cpc.ncep.noaa.gov/products/a ... ts-web.pdf

Will be interesting,September was unusual in my area in that nearly all the months rain come from the west,looking forward to seeing what La Niña brings in October and the also rest of summer.

I was speaking to Bob McDavitt earlier this week and he said westerlies have dominated Canterbury due to the break down of the polar vortex. However he said that "La Nina is still rampant" and that it could be as extreme as 1988. I was born this year so I dont know what weather we had

1988 was quite cool in auckland and wet especially june onwards,the early part dry,though canterbury was much drier,it changed around xmas and lots of NE over the country through dec-feb and wetter than usual Taupo north wheres the SI and SW of the NI was drier than usual with plenty of sun,the trend continued to about september in a lesser form and the year 1989 ended on quite a westerly pattern and tasman lows.

The 1988 situation showed a quick flip - an El Nino JAS 1986 - JFM 1988 had barely ended when the La Nina started - AMJ 1988 - AMJ 1989. There was quite a mixed bag of results. 1988 was quite a warm year, the warmest since 1971, and at Christchurch the warmest on record to date. It was a cloudier than usual year in Westland and the northern half of the North Island excluding Gisborne, and unusually sunny in Canterbury and to a lesser extent Otago. Rainfall was exceptionally low over the Canterbury plains (record low at Christchurch). Much of the northern half of the NI was a bit wetter, the southern half drier, especially Wellington. The south, west and mountain areas of the South Island were wetter, with record rainfall at Milford. The rest of the SI had well below average rainfall.

October 1988: Continuous W/NW airstreams, windy, huge rainfall contrasts in E-W rainfall in the South Island, drier than normal over much of the country, warmest October since 1962, very dull on West Coast, sunnier in N & E regions.

November 1988: Near normal windflow, but more NE than usual over the north of the country. Drier than usual in many parts, a little wetter in SW of the North island, warmer everywhere, cloudier than average in northern half of NI, sunnier in SI hinterland.

December 1988: Considerably wetter than average in Auckland, South Westland and Fiordland. Drier over most of the rest of the country. Warmest December since 1934. Sunshine above normal or well above normal except in Northland, Auckland and Bay of Plenty.

1989: report later.

Thanks for that RWood, I always enjoy reading your informative posts.

Cyclone Bola was early March of 88.

could be the summer to get a Cyclone me thinks....mark your calenders!

Manukau heads obs wrote:could be the summer to get a Cyclone me thinks....mark your calenders!

heres hoping!

have not had a decent one since about Fergus and Drena. I only have memory of Drena though because it delayed our holiday up north with the slip on the Brenderwins

Yes, certainly a higher risk of Tropical Cyclones developing this summer. NZ could be the dumping ground for some tropical moisture! And I think there may be a higher risk of thundery downpours over some parts of the country such as the west of the North Island and inland Otago and Southland.

Remember very well an extremely strong NW gale in mid-October 1988, affecting Canterbury. Things must have been dry - think there were a number of fires at the time too. Not a good season for farming.

Orion wrote:Remember very well an extremely strong NW gale in mid-October 1988, affecting Canterbury. Things must have been dry - think there were a number of fires at the time too. Not a good season for farming.

My brother and his Aust. wife enjoyed it - at the time it was the warmest, driest and sunniest year on record at Ch'ch. They could almost pretend they were living somewhere warmer.

I remember that period well with extended nor' west periods that lasted a week or so at a time instead of a day or 2.

It was very dry and dust was a real problem as well.

RWood wrote:
October 1988: Continuous W/NW airstreams, windy, huge rainfall contrasts in E-W rainfall in the South Island, drier than normal over much of the country, warmest October since 1962, very dull on West Coast, sunnier in N & E regions.
1.

October 2010 looks more Anticyclonic at this stage atleast for the first couple of weeks.

Yes, at this point it's more like several past spring months during a La Nina onset - eg November 1970, October 1973, October 2008.

Most anticyclonic Octobers in central NZ (from Kelburn records 1911-2009) - average is 1013.3:

1963 1021.7
1937 1021.2
1961 1021.1
1967 1019.4
1999 1019.4
1914 1019.0
1950 1018.7
1954 1018.3
1929 1018.2
1952 1018.0
1973 1017.9
1934 1017.8
1985 1017.8
1920 1017.6
1942 1017.6
1917 1017.5
1960 1017.4
1966 1017.3

Story about the coming Queensland Cyclone season http://www.weatherzone.com.au/news/earl ... -qld/15129
NewZealand can be in the firing line from Coral Sea Lows

Here's the latest SOI chart from BOM.


JohnGaul
NZThS

NZ Thunderstorm Soc wrote:Here's the latest SOI chart from BOM.


JohnGaul
NZThS

Wow thats very interesting!

That purple shade on the map says it all

Thats the most simple SOI chart I have ever seen if ever I saw 1, LOL

Queensland Cyclone season

The Americans were picking an active hurricane season for the Gulf of Mexico due to La Nina, but it never happened. The sea surface temps were hot but I think upper level shear was preventing GOM hurricanes from developing.

just started a new thread in case no one is on this one, but i'm trying to find out what la nina would mean in the alps, especially arthurs pass to cook in january. I'm wanting to do a high traverse through the glaciers ect and wondering if la nina is a good time for it, or a really bad time to attempt it. ideas would be apprciated. cheers