NZ Weather Forum

RWood wrote:
Most areas have been drier than average, with the more westerly parts and much of the South Island a long way below average.
Certainly in my area its been very wet in the last two months,100% above this month,yet 80kms to the south are still below the average for July

By a "bad" winter I presume you mean a cold one - none of the reputable forecasters were predicting a colder than average winter, as far as I can recall.

I remember Niwa saying back late April-May that because of warmer sea temps between NZ and South America and that this pool of warm water was moving west,winter may have been a little warmer than average

Richard wrote:
Certainly in my area its been very wet in the last two months,100% above this month,yet 80kms to the south are still below the average for July

I remember Niwa saying back late April-May that because of warmer sea temps between NZ and South America and that this pool of warm water was moving west,winter may have been a little warmer than average

Your area is one of the few with a substantial surplus. 70% of the South Island and about half of the North Island is below 50%, and below 20% in some parts of the SI. Refer to the rainfall month-to-date maps (latest 25th).

https://secure.niwa.co.nz/climate-explorer/home.do

The NIWA predictions for both May-July and June-August suggested average or above average temperatures (above more likely in the North Island, average more likely in the South). Their May-July predictions for rainfall are definitely well off the mark (much wetter in the east, and much drier in the west, than predicted) - in their probability terms it's been an unlikely outcome. The June-August ones are for near normal rainfalls over most of the country. Even if August is very dry in the east and very wet in the west and south of the South Island, there will probably be considerable deviations from that for a large area.

Thunder here @ Paerata.. very close strike visible by both myself, young fella & missus in Pukekohe, just so happened as an aircraft went for long finals overhead at the back end of the storm, hope it didnt get hit.

Well I'm looking forward to this low forecast for the weekend, models have been fairly consistent on a mid west coast crossing on Sunday so looks as though my area should get some fairly heavy falls. I'm used to seeing plenty of rainfall in winter so I feel a bit left out when its fine and dry for any length of time. (although having fairly consistent rainfall all year is much better!) Anyway after a rather dry start to the month for this region I don't think another decent fall will be that unwelcome here especially now we are only just over a month from spring.

Good to see this area is mentioned in the latest Severe weather outlook on Metservice, even if it is a 'low confidence' event its still a good sign that we should get something interesting!

Breif showers here with the southerly change this morning. Reports of snow showers around tekapo this morning light snow settled down to around 600/700m.

Colder here now than earlier,had some showers then sun otherwise the westerly is fresh at times not that windy yet then the odd gust.13c.

Southerly came through around 10am abit strong and gusty, and dropped from 9C to 5C at work with passing light showers until 2pm and the sun came out.
Both arthurs and lewis passes were closed due to snow this morning too.
Now we are into another settled patch for 3 days and might be our last settled patch for awhile looking ahead at longrange models.

Michael wrote:Colder here now than earlier,had some showers then sun otherwise the westerly is fresh at times not that windy yet then the odd gust.13c.

Yes I was surprised by the lack of shower activity today...was heaps more yesterday

Yesterday we didnt get much till the evening/night before.We were quite sheltered from the wind all day until it changed around the 6 oclock news time.

Dale,that CB looked impressive from waiuku at soccer training for the young fella when I was in there...wish I had my camera with me...
David, lots of shower activity in the waiuku area from 4pm onwards, and we had a very heavy shower here at 5:30 pm (5mm)

Well I'm looking forward to this low forecast for the weekend

um? dum question from amatuer...this is something i don't get. where is the low?? see below fcast from metservice that looks like a big fat high to me...i am confused!

Thats fridays map,by sunday a NW flow should spread on the country.

vinodrinker wrote:

Well I'm looking forward to this low forecast for the weekend

um? dum question from amatuer...this is something i don't get. where is the low?? see below fcast from metservice that looks like a big fat high to me...i am confused!

but that is fridays forecast map, not the weekend forecast map
you can see the low near tasmania

the models have it more like a wave depression now, followed by a bigger low on tuesday, which may bring cold easterlies to eastern SI...(according to GFS (long way out))

dammit!! can someone ask the anticyclone to put da handbrake on for another couple of days?

Manukau heads observer wrote:Dale,that CB looked impressive from waiuku at soccer training for the young fella when I was in there...wish I had my camera with me...

Yeah I wish my camera wasnt on the blink, lots of popcorn about yesterday. It was just that 1 ground strike though & it was pretty damn close, within a couple of km's.. like said, just so happened as a Jetstar A320 was skirting around it on approach to NZAA, then flash.. kaboom! That was it.

Nice to hear that strange sound again though

Jetstar A320 was skirting around it on approach to NZAA, then flash.. kaboom!

I have often wondered whether aircraft or tall structures like the sky tower can trigger lightning. I'm thinking a cb that is on the verge of a discharge and a tall building or aircraft can act as a catalyst for the discharge. I haven't done much reading on this topic but in the past I have come across opposing scientific opinions on it. My own thoughts are that lightning can be triggered this way.

NZstorm wrote:

Jetstar A320 was skirting around it on approach to NZAA, then flash.. kaboom!

I have often wondered whether aircraft or tall structures like the sky tower can trigger lightning. I'm thinking a cb that is on the verge of a discharge and a tall building or aircraft can act as a catalyst for the discharge. I haven't done much reading on this topic but in the past I have come across opposing scientific opinions on it. My own thoughts are that lightning can be triggered this way.

Really anything that conducts better than air is will be more likely to attract lightning.

I'm referring to lightning that otherwise wouldn't have happened Tim.

Tornado Tim wrote: Really anything that conducts better than air is will be more likely to attract lightning.

Let's face it; we're reducing the capacitance of a giant air capacitor!

Lightning will 99% of the time go for the tallest structure.. I think the people on the JQ airbus would have been ok or it would be plastered all over the news by now.. just found it ironic, young Jarred was cooking up some noodles, I was staring out the kitchen window looking over the Bombays and bang, whiteout.. definate ground strike somewhere between here & Ramarama. The sound resonated right through the valleys.

NZstorm wrote:I'm referring to lightning that otherwise wouldn't have happened Tim.

There was a case in 1995 where a Super Puma helicopter ran into poor weather and was then struck by lightning while carrying oil workers from Aberdeen to an oil platform in the North Sea. This caused severe damage to the tail rotor, which eventually failed completely and the pilot was forced to perform an emergency autorotation onto the rough seas. Remarkably all on board survived. The lightning strike was an isolated one in the storm, and is thought to have been induced by the helicopter flying through the cloud...

Bristow Flight 56C: downed by lightning - Aviation-Knowledge

...Investigators found that it was not ordinary lightning that hit 56 charlie but charged up static caused by the aircraft's own tail rotor. The tailrotor was made out of carbon fibre and that conducts electricity. It created with the static in the air about 30 billion watts and struck!

Lightning is fascinating stuff. Every 20 to 50 micro seconds jumps occur as leaders down initially and then up to meet. Aircraft are known to trigger lightning. Electrostatic charges built up on the aircraft help leader generation, not to mention the conductive path they offer helping.

There was a helicopter flying to oil rigs in the North Sea off the UK that got hit by the only lightning bolt in the storm, it was a huge discharge that destroyed the tail rotor. Only the combination of the gearbox of the tail rotor not falling off and the pilots managing to perfectly time the counter rotation meant everyone survived ok.

Huge inroads into understanding how lightning occurs has been happening lately thanks to the modern ultra high speed high resolution cameras.

Next weather meet I'll show you some video I've compiled.

Have a look at some of the video on youtube.

With radio sites we tend to provide an electrical path to ground from the highest point. We then consider it to provide a 45° cone of protection, we keep the equipment aerials inside this conical assumed area of protection.

Snap! Thanks Nev.

vinodrinker wrote:dammit!! can someone ask the anticyclone to put da handbrake on for another couple of days?

As long as it parks up over you, anticyclones mean frosts for us down here

NZstorm wrote:I'm referring to lightning that otherwise wouldn't have happened Tim.

Yea I got you the first time.

I was just adding to what you were saying

Looks like once this high comes through there will be another Low coming