NZ Weather Forum

I see One News used a few seconds of my video in their TV news story

The sudden stratospheric warming in early May was so powerful, that tropospheric polar vortex is now in more disarray then it was a week ago. In 72 hours, the polar jet stream will deform over NZ associated with a another powerful upper low, ballooning a cold upper pulse into the tropics, while an interacting divergent limb will connect with the subtropical jet.

It was always an unknown on what the follow on impacts the SSW would trigger but this is an incredible set up impacting the Hadley, Ferris and Polar cells normal functions. IMO, there is likely to be substantial synoptic scale weather impacts on NZ weather in the next 10 days. Models will be erratic as the jets are in extreme positions. The disturbance in the tropics will have to be watched very closely from next weekend for NZ in my opinion.

It’s all linked and this earthnullschool shows how the jet positions are going to trigger the extremes ahead. https://earth.nullschool.net/#2018/06/0 ... 44,-61.117

Isolated power outages in rural areas South of Cambridge caused by a sudden increase in wind speed about 5pm . A PWS operated by flight training school at Hamilton airport recorded a 92kph gust just after 4pm. Something going on right on the Western boundary of that large area of rain on radar at time.

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Interesting how the earthnullschool graphics show the size difference of the jets between the two hemispheres.

cbm wrote:Isolated power outages in rural areas South of Cambridge caused by a sudden increase in wind speed about 5pm . A PWS operated by flight training school at Hamilton airport recorded a 92kph gust just after 4pm. Something going on right on the Western boundary of that large area of rain on radar at time.

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Yea so we had a weird wind after the rain. Not long after the rain finished and just before the Mammatus the wind really ramped up. Nothing spectacular in speed but very noticeable. Then it suddenly dropped away but the clouds were fair honking it. Really noticeable how fast they were moving. Then the wind came back again all of a sudden. This pattern repeated a few times. The wind was an odd direction. I expected the wind to go westerly of some kind after the rain but it stayed SE.

I’d be interested if someone could do some meso scale analysis on today’s setup. It was really odd in my eyes.


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The 92km/h gust recorded near Hamilton Airport is interesting. It was not a tornado though.

Tomorrows set up over Northland/north Auckland looking favourable for lightning. There has been very little with this system so far. We have the 500mb vortex moving in which will steepen lapse rates add lift.

Had about 10 flashes Katikati-Tauranga from 3-6 pm . Yes tomorrow eve looks exiting and more flooding no doubt , tornado or 2 as well on the cards as the shear kicks in .

999.6 hPa and falling, 14.5c and a 14c DP. Cape Reinga 995 hPa and falling

Access R and UKMet on the 12Z run project the centre of the low to now be 988 hPa (9am NZT).

Clusters continue to decay and strengthen on and NE from the Upper NI. Variety of CG and CC's within the cells

NZstorm wrote: ↑Sun 03/06/2018 22:13 The 92km/h gust recorded near Hamilton Airport is interesting. It was not a tornado though.

Tomorrows set up over Northland/north Auckland looking favourable for lightning. There has been very little with this system so far. We have the 500mb vortex moving in which will steepen lapse rates add lift.

No suggestion of a tornado but I drove into the front, it had a very abrupt edge to it, and at one stage looked like wind changed direction by about 45 to 90 degrees within a couple of minutes.
Metservice's own site at Hamilton airport recorded a 76km gust which is up there for that site - second highest in the country yesterday which is rare. Their site is about 500m North of the Flight Training's PWS and away from any buildings.
Grabbed radar image of the time before it falls off the last 24 hours. Also got to see the Mammatus - was hard to miss.

Moisture levels in the mid to high levels are increasing again over the Hauraki Gulf in the last 30 min. Winds are NE north of Auckland, easterlies here. It's squeezing again

Just looking at some of my historic weather station data, as I've noticed there have been a lot of heavy downpours here in recent times. In records starting Dec 2009, there are 5 instances of hourly totals >30mm, with 4 of them occurring in the last 1.5 years of records:

36.4 (5 March 2011)
35.2 (27 March 2017)
35.2 (3 June 2018)
35.0 (14 April 2018)
33.6 (4 April 2017)

heavy rain, some lightning and thunder atm

Had a flash with 3 seconds to thunder. IC lightning I think.

Was pretty close to here as well. Quite loud. Only light rain though.

A brief gusty heavy shower here with the thunder, otherwise patchy light to mod rain last hr. Front over Auckland now.
More thunder now just east of here.

More thunder here. Looks like some action about to move in from the Gulf

Some pretty bad flooding around Tolaga Bay I see. A council rainfall station inland from there recorded some very intense falls of rain:

A lot spherics on the am band, every 5 seconds. But the range is wide and likely a lot of it over the Hauraki Gulf/Coromandel.

Heaps of loud thunder east of howick but not seeing much lightning...

Waiheke, east and south Auckland in the firing line for storms.

Yeah, had a nice wee burst of thunder/lightning to the east of Waiheke just before midday, then it just went a little blitzorlistic between about 1pm and 2pm…

A new line coming through now with isolated thunder activity, intense shower here now.

Certainly is an active wrap around from the NE off the upper NI. Another quick heavy downpour, 995.6 hPa, 15mm so far.

Sat pic certainly looking cold in the southern ocean. Interesting to watch how the 2nd low circulation plays out tomorrow morning off the NI & SI. My 2 bobs worth on the 3.30pm image with surface positions.

Torrential shower here. Surface flooding again