Polar Jet Amplification

[Lawrence]

Looking like as we come further into winter the polar jet seems to be getting more amplified and the sub tropical jet seems to be leveling out and breaking apart beyond what seems to have been normal during the la nina period. Possibly heralding the approaching end of la Nina, will be interesting how a possible cold snap mid week turns out as it seems to be starting a similar scenario to the last couple of cold blasts we have had. Any opinions on this are welcomed.

[NZstorm]

Good riddance to La Nina. It did us no favours and gave Auckland and the country the most boring run of weather. Outlook for the rest of the year is for ENSO nuetral. I expect to see the high lattitude westerlies to spread north into the mid lattitudes during July. This should bring an increase in rainfall to the west and north of the country. In the shorter term, yes the GFS suggests another shot of cold air moving across the country mid next week with a risk of snow to lower levels. Maybe its to early to go into detail on this though, give the models a couple more runs.

[Michael]

At least it gave Auckland some resembalance to what summer should be more like rather than the usual lucky to exceede 25c garbage summers been especially since the start of this decade.

[David]

RIP La Nina! You have been nothing but trouble!
April and May made up for the drier previous months, with 262mm in those 2 months - however these totals are not overly high. But now June has been dry, at 17mm so far.
We'll be needing a couple of months around 200mm rain to get to average by the end of year (436mm now). Some of the drier parts which have yet to reach 300mm will need some very wet months to reach average!

At least it gave Auckland some resembalance to what summer should be more like rather than the usual lucky to exceede 25c

Yes Michael, I don't think I will be recording a summer month with an average high above 25C again anytime soon! Owairaka has only had a few months where mean daily maxima were 25.0 or higher, Jan 1962, Feb 1978, Feb 1990, Feb 1998 (26.2C!) and I suspect Jan 2008 as well but there is no value available for this month.

On a different topic, the Cropp River rain gauge in Westland has recorded 420mm of rain so in the last few days, 20mm on the 12th, 311mm on the 13th and 92mm today. Maybe this is the start of the return to more frequent rain bearing-westerlies there?

[Myself]

RIP La Nina! You have been nothing but trouble!
April and May made up for the drier previous months, with 262mm in those 2 months - however these totals are not overly high. But now June has been dry, at 17mm so far.
We'll be needing a couple of months around 200mm rain to get to average by the end of year (436mm now). Some of the drier parts which have yet to reach 300mm will need some very wet months to reach average!

At least it gave Auckland some resembalance to what summer should be more like rather than the usual lucky to exceede 25c

Yes Michael, I don't think I will be recording a summer month with an average high above 25C again anytime soon! Owairaka has only had a few months where mean daily maxima were 25.0 or higher, Jan 1962, Feb 1978, Feb 1990, Feb 1998 (26.2C!) and I suspect Jan 2008 as well but there is no value available for this month.

On a different topic, the Cropp River rain gauge in Westland has recorded 420mm of rain so in the last few days, 20mm on the 12th, 311mm on the 13th and 92mm today. Maybe this is the start of the return to more frequent rain bearing-westerlies there?

Is that the one near the "waterfall"?

[David]

Is that the one near the "waterfall"?

It is called "Cropp River @ Gorge". These are West Coast Regional Council Rain Gauges and I'm not sure whether or not Metservice/NIWA would use them for data. "Cropp River at Waterfall" is the official gauge for the Cropp River area - but these sorts of 'official' networks are not made viewable to the public sadly . I'm assuming however that the council gauge is a good representation of the official data.
Here's the link: West Coast Rainfall

[RWood]

The Cropp gauge at "Waterfall" has been quoted by NIWA for some years now, in various record lists. Average annual rainfall is over 10,000 mm (12-month record is 18442). It has been mooted that some parts of the W Coast uplands might average up to 13000 mm.

I don't agree with the negative comments on La Nina - I think there were several positives.

[Myself]

I don't agree with the negative comments on La Nina - I think there were several positives.

I agree....but we live in Wellington!

[Michael]

Wanganui in the same boat too,I couldnt believe how horrible ie wet and windy it was in Ak after Wanganui too.

I don't agree with the negative comments on La Nina - I think there were several positives.

I agree....but we live in Wellington!

[Vertigo]

slightly on topic a researchers views on the jetstreams migration as of late.
http://sciencentral.com/articles/view.p ... =218393120