General May Weather

[NZstorm]

I have been watching the thunderstorms approach Auckland from the NW. It seems as though the thunderstorms died out as they hit the coastline. Can anyone explain why they didn't make much ground inland?

That is usually what happens. But I'm not too sure why it happens so often...

With deep layer NW flow storms typically will not make it far into Auckland.
The exceptions to the rule are if the storms are elevated or if there is a decent surface NE.
I think the hill country to the west is a big blocker as well as the cool land at this time of year. Also the instability numbers with these set is not very high and it doesn't take much to kill it off.

[Manukau heads obs]

it was a powerfull thunderstorm here in this district
blew out a transformer on a power line not far from us here

[Manukau heads obs]

looking like a fine Queens Birthday weekend for all of NZ
when did that last happen?

[MadDog]

With deep layer NW flow storms typically will not make it far into Auckland.
The exceptions to the rule are if the storms are elevated or if there is a decent surface NE.
I think the hill country to the west is a big blocker as well as the cool land at this time of year. Also the instability numbers with these set is not very high and it doesn't take much to kill it off.

Thanks NZStorm. What do you mean by deep layer NW flow? Does this mean deep as in low in elevation? Where would i find instability numbers?

Cheers

[NZ Thunderstorm Soc]

looking like a fine Queens Birthday weekend for all of NZ
when did that last happen?

Yes, sadly, although I don't mind.
The recent low pressure system did nothing much here, but delivering needed rain on the overnights, with snow upcountry, but, in the daytime, a lot of clear skies and not much wind, so this incoming anticyclone may bring a continuance of this weather before winter settles in, if it does?

[hozza95]

Meanwhile we have just had our 19th consecutive day with rain recorded, though the falls have been fairly light with only 4 of those days with 10+ mm's.

[jamie]

20 days in a row here I think. This is after the driest YTD we have recorded at may 10th.

[David]

It will be another below average rain month here - only on 71mm for the month. It feels like it's been a wet month but really we have just been getting showers every day the last 2 weeks... no significant heavy falls.

[einzack]

I saw on Facebook (so it must be true right?) that Hokitika has recorded it's wettest May on record - stretching back to 1866. As of yesterday they'd notched up 569mm, beating the previous record of 561mm recorded in 1877.
That's a decent drop. It'll be interesting to see the NIWA analysis for May as I suspect it might not be the only place showing a similar story.

[Razor]

Meanwhile in Chch.... Our first 'chain shower' set up for yonks ... or Southerly shower set up, whichever you prefer

[hozza95]

Snow on the Highgate bridge cam in Dunedin, sleety with flakes here

[SnwAddct]

Woke to a distant thunder rumble this morning about 5am. I have now lost count of the ammount of thunder and lightning we have had in the last 2-3 weeks, love it!

[SnwAddct]

Surprised at the ammount of snow Ruapehu ended up with over night. Was only expecting 10mm max from that front but looks to be atleast double..

[SnwAddct]

As far as rain radars go what are our options guys? Something a little more high res that you could zoom in on rather than the metservice one would be bloody awesome..

[treetop]

What radar ? nothing this morning !

[Manukau heads obs]

the M/S rain radar has been very reliable of late..though..to be fair (compared to in the past)

[NZstorm]

Cold morning with 7C.

My rain guage collected 105mm while I was away 19th-31st. Some small hail yesterday afternoon in Grey Lynn.

[Nev]

A record breaking warm May, but also genrally quite wet and cloudy, except for some eastern and northern areas.

May 2016 Climate Anomaly Map ℅ NIWA.gif

May 2016 was the warmest May on record for all the main-centre sites, except for Dunedin, which had its 4th warmest May. Some very preliminary May 2016 figures for the main centres:

Code: Select all

May 2016 Average Temps, Rainfall and departures from their 1981-2010 normals ℅ NIWA

Site (* May record)       T-max °C        T-min °C        T-mean °C      Rainfall mm

Auckland, Mangere        20.0*  +2.5     13.3*  +2.9     16.7*  +2.7     120   111% 
Auckland Aero            19.8*  +2.4     12.8*  +2.2     16.3*  +2.3     153   140% 
Tauranga Aero            19.3   +2.0     11.9*  +2.6     15.6*  +2.3      89    80%
Hamilton Aero            18.7*  +1.9      9.4*  +3.0     14.0*  +2.4     140   131% 
Hamilton, Ruakura        19.0*  +2.1      9.8*  +2.9     14.4*  +2.5     121   125% 
Wellington, Kelburn      16.1   +1.8     11.4*  +2.4     13.8*  +2.1     234*  210%
Christchurch Aero        17.4*  +3.1      6.4   +2.7     11.9*  +2.9      99   172% 
Dunedin, Musselburgh     15.0   +2.3      6.7   +0.8     10.9   +1.6     127   195%
Greymouth Aero           14.8   +0.3      9.1   +2.0     11.9   +1.1     479*  243%

Many new May rainfall records were also set this month, including an impressive 1338mm at Milford Sound, most of which fell in the first half of the month.

[Manukau heads obs]

that tellies well with my own data
http://www.weather-display.com/windy/gb ... taout.html
which shows a 2.1+ above my average

[Tornado Tim]

2.2°C above normal for Matangi at an avg temp of 13.8°C ,not surprising...., May 2011 was similar though at 13.5°C avg temp.
2011 was a year that the cooling when approaching winter was significantly delayed by an 'indian summer', but when it come to warm up towards summer it was delayed as well.

Will be interesting to see how we further transition into Winter than spring if we follow that same pattern

[Manukau heads obs]

I see Brisbane/Queensland had its warmest May on record
and Australia on a whole its warmest autumn on record

[Manukau heads obs]

I also see that Lincoln Uni has had its warmest May , with records going back to 1881

[Nev]

Here's NIWA's preliminary, 'May National Climate Summary'.

Warmest May on record and plenty of rain for western regions


The national average temp of 12.9C was 2.1C above normal.

The faulty reading of 27.6C at Kawerau on the 9th is touted as the month's highest temp, while the lowest temp of -5.6C was recorded at Ranfurly on the 25th.

Also see new NIWA brief Video Summary.

[Nev]

Thought these anomaly maps might also be of interest, as they show just different the first and last half of May was in most areas in terms of rainfall and temps…

May 2016 Climate Anomaly half-maps ℅ NIWA.gif