NZ Weather Forum

Isolated to scattered heavy showers inland both Islands this weekend with cb tops cold enough for possibility of a little lightning, particularly tomorrow. The dewpoint at Taupo this morning is 15C.

Looking like yet another 25C day for Auckland today due light winds.

I wont have to drive every far as i'm on the moderate risk line. We'll see if that changes much with this evenings update.

Apparently there were some thunderstorms down south around the Queenstown area today according to MS Facebook page and Dan on the telly.
Went to the Orari Races today and the sky looked good with a lot of castellatus forms in the sky.

NZ Thunderstorm Soc wrote: ↑Sat 25/11/2017 15:02
I have always interpreted 'showers, some heavy' as being a thunderstorm without lightning as described in your/MS for 'locoalized downpours' and at several stages on this forum, I still really, haven't found out what the difference is between 'showers, sometimes heavy and thundery' ' and 'showers with isolated thunderstorms'

Here is what I meant with tonights 11pm forecast.
New Zealand Short Forecast
Issued: 11:21pm Saturday 25 Nov 2017
Valid to: Midnight Sunday 26 Nov 2017
Northland, Coromandel Peninsula, and Bay of Plenty
Cloudy periods and isolated showers.
Auckland and Waikato
Often cloudy. A few afternoon and evening showers near the west coast.
Waitomo to Manawatu, including Taupo, Taumarunui and Taihape
Mostly cloudy. Scattered showers, mainly afternoon and evening, some heavy and possibly thundery.
Horowhenua, Kapiti Coast and Wellington, also Gisborne to Wairarapa
Often cloudy. Isolated showers, mainly about the ranges, possibly heavy and thundery later.
Marlborough, Nelson, Buller and Westland
Fine breaks, but isolated afternoon and evening showers about the ranges, possibly heavy and thundery with small hail.
Canterbury, Otago, Southland and Fiordland
Fine breaks. However, cloudy about the coast this morning with patchy drizzle. Scattered afternoon and evening showers inland, some heavy with thunderstorms and hail.
Chatham Islands
Often cloudy.
Funded by NZ Government

Looks like a monsoon over parts of the country next 7days!

Today's thunder chances look best inland Otago/Canterbury(along the foothills). Wind shear is very weak so individual cb cells will be short lived with small hail.

There's not much prospect for lightning over the North Island today in my opinion although isolated instance not out of the question given scattered showers south of Taupo.

Nice day here with ENE sea-breezes.
Not looking all that thunderstromic inland although there are a few Cu build-ups.

NZ Thunderstorm Soc wrote: ↑Sun 26/11/2017 16:26 Nice day here with ENE sea-breezes.
Not looking all that thunderstromic inland although there are a few Cu build-ups.

Heavy thundery showers in Central Otago and inland South Canterbury, also over volcanic plateau in the NI.

A PWS in Roxburgh has had 26mm in the last hour.

Yes.
Noticed a huge Cb anvil top to the WSW of here with some other Cb top layers drifting NE high in the sky over Timaru, since my previous posting.

Drove from Taihape back home today. Showers were developing on the desert road. Incredibly hazy all the way to north of Taupo.

Inlaws say they have had thunder and rain all afternoon in Taihape.

GFS indicating the afternoon shower pattern for inland areas will continue right through the week.

We will probably see some afternoon showers for Auckland later in the week.

I could see the cbs from chc down over inland Timaru/Oamaru way. Its too late to drive to them once you see them that far away, haha.

Reports of widespread surface flooding from storms in Roxburgh and State Highway 8 is closed from slips.

Updated rainfall chart for next 7 days. A lot of precip for inland areas.

Aucklander's could catch a thundery downpour Thursday but that a bit long range at this stage.

RichyDunedin wrote: ↑Sun 26/11/2017 18:43 Reports of widespread surface flooding from storms in Roxburgh and State Highway 8 is closed from slips.

68mm since 3pm, I'm not surprised.

RichyDunedin wrote: ↑Sun 26/11/2017 18:43 Reports of widespread surface flooding from storms in Roxburgh..

i hope that the Jimmys pie shop wasn't flooded out

https://www.odt.co.nz/regions/central-o ... lowed-home

Yea haha hope the Jimmys pies are safe.
The main street of one of NZs driest towns isn't looking so dry today.

RichyDunedin wrote: ↑Sun 26/11/2017 21:04 https://www.odt.co.nz/regions/central-o ... lowed-home

Yea haha hope the Jimmys pies are safe.
The main street of one of NZs driest towns isn't looking so dry today.

,,,,thnak goodness for that
I love their mutton ones.
You get that in Australia in places where it dosen't rain for a while then all of a sudden you get a deluge which makes things worse than if it didn't rain at all

After a sensational sunny day in Arthurs Pass we punched through a very vigourous cell between Bealey and Castle Hill around 5pm. Lightning active with torrential rain at times, great example of convergence today, fresh westerly coming over the main divide meeting the easterly from the foothills. Once on the Canterbury plains you'd never have known it was happening further in due to lower cloud cover.

Todays flash flooding highlights how much the last radar is required. That Otago region is so poorly covered. Anyone know when it’s going to be installed?

Interesting pictures there,
Lots of flat cloud here this afternoon inland apart from some bubble-ups of Cu builds through that cloud around the Mt. Hutt area and up the Rangitata Gorge area.
Nothing much observed inland to look thunderstormic, except from about 3pm onward, you could see upper level Cb 'off cuts' if there is such a thing drifting east over the Timaru direction from here.
a more distinct Cb form drifted east later.
Had the AM radio going. Only heard one possibly lightning related sferic.

jamie wrote: ↑Sun 26/11/2017 21:32 Todays flash flooding highlights how much the last radar is required. That Otago region is so poorly covered. Anyone know when it’s going to be installed?

I was thinking that today with the events that are occuring in the Otago/Northern Southland today and possibly this week.
Might be a difficult area where to establish one, coastal, Otago penisuslar or around the Queenstown area, but mind you there are lots of hills/mountains around the Central Otago area.?
Maybe Mr Doppler could event a radar that can record rainfall that you can place anywhere without hills or trees or other obstructions that don't get in the way

Not often we have a convective outlook like the one we have. As someone has already mentioned it looks a bit monsoonal like.

Perhaps a mod could put the relevant posts in to this so it can be in the one topic.

Hard not to get excited with some of the GFS plots for this week

jamie wrote: ↑Mon 27/11/2017 09:11 Not often we have a convective outlook like the one we have. As someone has already mentioned it looks a bit monsoonal like.

Perhaps a mod could put the relevant posts in to this so it can be in the one topic.

Done, was expecting this was worth a thread myself

For posterity some screen grabs of the lastest TS Outlooks attached