Weak La Nina

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NZstorm
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Weak La Nina

Unread post by NZstorm »

Synopsis: ENSO-neutral or weak La Niña conditions are likely during the next 6-9 months.

Don't know if this means much really. La Nina tend to bring higher rainfall to the east and north.
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Unread post by Willoughby »

Easterlies for the north under a weak el nina.. this mean better risks of cyclones coming down?

Northland farmers would be happy after the last two summers.. which have been droughts
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Unread post by Willoughby »

Summary: A slight strengthening of the Walker Circulation over the Pacific.

ENSO indicators from the tropical Pacific indicate the neutral climate pattern is persisting. However, over the past two weeks there have been increased indications of a slightly stronger than usual Walker Circulation (the atmospheric circulation above the equatorial Pacific, which weakens/strengthens substantially during El Niño/La Niña events). Despite this slight strengthening, history, and the current outlooks from climate models, suggest it would be unlikely for any significant change from neutral conditions during the remainder of 2005 and into early 2006.


Observations from the Pacific region show Trade Winds near the equator have strengthened in the central equatorial Pacific over the past two weeks, while upper level winds have shown some periods of increase. This slight strengthening of the Walker Circulation is reflected in the value of the SOI, which has risen to around +12. Cloudiness along the equator has generally remained near normal. Sea Surface Temperatures experienced a small cooling late in October and into early November, which was largely a response to the strengthened Trade Winds, however they remained near average for much of the central equatorial Pacific. Subsurface temperatures, in general, remain neutral.
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Unread post by NZ Thunderstorm Soc »

Even though we are in neutral conditions, I thought that we were in a bit of a weak La Nina phase, especially with all the rain and thunderstorms up north
I prefer El nino conditions myself for thunderstorms here.

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Unread post by squid »

would be nice to have a weak la nina again summertime rain is so refreashing along with the storms of course ;)
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Unread post by NZstorm »

NZ does not want La Nina at the moment as the hydro lakes are low and la Nina will mean a continuation of below normal rainfall in the Southern Alps. Come next winter, the hydro lakes needs to be full.
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Unread post by Michael »

Its hard to say in 1997 which was elnino it was Rain the whole time until early Jan98 then it vastly improved.1988 was a lanina year again it Rained nonstop that year but improved at Xmas with a predominantly NE pattern that continued until August of 1989.
:lol:
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Unread post by RWood »

You're talking in a rather localised context. Though '88 was wet in various western areas with record totals in Fiordland it was dry in the east from Hawkes Bay to Otago, including Wellington. Christchurch had its lowest ever total. The SOI didn't reflect La Nina till July onwards. Don't recall the rainfall distribution for 1997 at this point.
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Unread post by NZ Thunderstorm Soc »

RWood wrote:it was dry in the east from Hawkes Bay to Otago, including Wellington. Christchurch had its lowest ever total

I think we had 30 out of the 31 days of October, that year with NW winds or winds from the westerly quarter :)

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Unread post by RWood »

That would be right. Kelburn in Oct 1988 surpassed 63kph gusts on 30 of 31 days, "average max. daily gust" that month was 97kph (that's measured on a 15m pole attached to Metservice building near Carter obs'y), a record for these stats which go back to 1972. The "average average" is about 66kph but has shown a general downward trend over the period. But of course it was also a very warm dry month in the east.
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Unread post by Gary Roberts »

RWood wrote:Kelburn in Oct 1988 surpassed 63kph gusts on 30 of 31 days, "average max. daily gust" that month was 97kph...
I can't even begin to imagine why it's often called 'Windy Wellington'... :shock:
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Unread post by squid »

i reckon it could be a cross between nutral conditions and a weak la nina
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Unread post by RWood »

Gary Roberts wrote:
I can't even begin to imagine why it's often called 'Windy Wellington'... :shock:
I can cut the place a fair bit of slack these days because its temp., rainfall and sunshine values have all improved over the last 30 years - and I live in one of the more sheltered parts of town. On non-climate matters it has plenty going for it.
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Unread post by Michael »

I remember going years ago as a kid,it was windy,moist,drizzelly and misty and had earthquakes at the same time.Now days its more settled than Auckland ;)
RWood wrote:
Gary Roberts wrote:
I can't even begin to imagine why it's often called 'Windy Wellington'... :shock:
I can cut the place a fair bit of slack these days because its temp., rainfall and sunshine values have all improved over the last 30 years - and I live in one of the more sheltered parts of town. On non-climate matters it has plenty going for it.
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Unread post by Gary Roberts »

RWood wrote:I can cut the place a fair bit of slack these days because its temp., rainfall and sunshine values have all improved over the last 30 years - and I live in one of the more sheltered parts of town. On non-climate matters it has plenty going for it.
If I had to leave the MacKenzie and was told to choose between Auckland or Christchurch, I'd probably move to Wellington! :D
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Unread post by Manukau heads obs »

farmers up this way will be happy to get a weak la nina if it means av/above av rain for summer/autumn
the odd low to the north lately surre has the signs of a la nina
but it might not start to kick in properly until after xmas OR new year...when there is often quite a marked change in the weather patterns to summer, from spring
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Unread post by squid »

I totally agree with you there mate woudl be great to have a above rainfall for the summer/autumn
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