Possible T-storms, Upper N.I. & Sth Canty - Oct 31

[NZstorm]

Modelling for Saturday showing up a decent upper level system sweeping the country with possible thunderstorm risks. Otago to Northland.

[spwill]

GFS has dps of 17-18C modelled for Northland/Auckland on Saturday with cool upper air, something to watch.

[Chris W]

Modelling for Saturday showing up a decent upper level system sweeping the country with possible thunderstorm risks. Otago to Northland.

DP, moisture and wind directions (N/NE to SW/S) look interesting on GFS, uppers aren't very cold though and quite a lot of cloud around so not much heating. Though MS say becoming fine before showers with a max of 26C, so guess they feel the cloud will break.

My hunch is low risk.

[tornado]

yes risk for something this weekend. hope it actually happens as i seen to many busts this year.

[Chris W]

Some unexpected rain the past couple of nights here, very welcome although I did just cut the grass last weekend

Interestingly MS are going moderate storm risk for inland Otago and South Canterbury tomorrow, low up to Chch probably due to timing. Uppers are warm but DPs are good if convergence gets going.
https://www.metservice.com/warnings/thu ... rm-outlook

[tornado]

ad a risk of thunder upper north island tommorow as well. hope tommorow delivers here.

[mikestormchaser]

Tomorrow is an interesting one. There is some cloud cover morning but that looks to clear in afternoon.
Freshening NW later before the change.
Not overly cold aloft but surface conditions can over ride that. Id say looking at models the MS is on the money with there outlook chart

[Storm Struck]

There's not quite as much instability on the latest runs there now, just - 1c LIs and 200 Cape, the last few days it's been quite high cape.
The only thing tomorrow that has something going for it is the potential for coastal sea breezes to get going prior to the SW change as the ridge opens up.
Upper air is warm and there's no strong upper jet either so the hail will be small I'm picking.
Given what I can see id go low risk.

[NZ Thunderstorm Soc]

There's not quite as much instability on the latest runs there now, just - 1c LIs and 200 Cape, the last few days it's been quite high cape.
The only thing tomorrow that has something going for it is the potential for coastal sea breezes to get going prior to the SW change as the ridge opens up.
Upper air is warm and there's no strong upper jet either so the hail will be small I'm picking.
Given what I can see id go low risk.

Could be a repeat of October the 14th for here? Have to wait and see what happens?

[NZstorm]

Last day of October, can we bag a thundery downpour in Auckland to finish the month? Heating will increase the odds as that front moves across this afternoon. Dewpoint forecast to be 17C and forecast max temperature is 23C. Upper winds are strong so cb's won't be hanging around.

[Nev]

Thought today's events might warrant its own thread.

MetService Thunderstorm Outlook

Issued at 8:12am Saturday 31 Oct 2020
Valid to Midnight Saturday 31 Oct 2020

A series of fronts move over the country today.

Showers are expected for much of the North Island and northwest of the South Island. Wind convergences are expected to set up ahead of the fronts over the upper North Island early this afternoon and there is a moderate risk of thunderstorms associated with these, and the fronts, for northern Taranaki to western Bay of Plenty northwards to Northland this afternoon and early evening. If these thunderstorms occur they will be accompanied by localised heavy rain of 10 to 25mm per hour. There is a low risk of thunderstorms for remaining western areas of the North Island, also the Tararua District, and the northwest of the South Island as indicated on the chart.

A cold front moves north over the east of the South Island during the second half of today. There is a low risk of thunderstorms for Canterbury south of Rangiora and parts of North Otago this afternoon and early evening, with the risk of thunderstorms increasing to moderate for inland parts of South Canterbury, especially near the foothills. If these thunderstorms occur they will be be accompanied by localised heavy rain of 10 to 25mm per hour and small hail.

Elsewhere, no thunderstorms or significant convection expected during this period.

MetService T-storm outlook - Oct 31, 8.10am.png

[spwill]

On the humid side with 18C, 17Cdp by 9am, skies should hopefully brighten up here next hr or two for some heating. Will watch for Cb development in the afternoon.

[Awhituobs]

Nice looking rain band out to my west
I can see the billowing clouds
We should get the rain here.yah

[cbm]

Have caught some showers in the past week, now up to 56mm for the month. To my eyes everything is growing very fast. Still only 552mm YTD, but there do seem to be signs this Summer wont be like the last two. We'll see.

[tornado]

I think we in for a good downpour. Hopefully a thunderstorm too.

[David]

Peak dewpoint of 18.9C here today. New October record for me

[Awhituobs]

7mm at our place.yah

[David]

Distant thunder rumble here just now, 5mm rain so far

[Nev]

Rain has just arrived here - hearing distant rumbles and one decent peal just now.

Akld Lightning - Oct 31, 2.22pm.png

[Cyclone Tracy]

No luck hearing any rumbles from here, just out of range, 2.4mm so far. Might squeeze out a few more mm in the next few hours.

[NZ Thunderstorm Soc]

Few clouds around here but not looking potential enough for any TS activity although the Blitz recorded 2 strikes way up the Rangitata Gorge area.
Been very warm though with a light N to NW.

[Orion]

Interesting line of clouds visible to the south, have just gone around closing windows; awaiting developments.

26.6°C at the moment.

[NZ Thunderstorm Soc]

Could be something interesting down Oamaru way
Keeping an eye on it.

[Orion]

The line of interesting clouds I observed earlier (they were probably around the Rangitata River at that stage) collapsed and fizzled out.
Wind still WNW.

25.0°C

[NZ Thunderstorm Soc]

The line of interesting clouds I observed earlier (they were probably around the Rangitata River at that stage) collapsed and fizzled out.
Wind still WNW.

25.0°C

I saw them from here but didn't have enough ooomph in them.
Starting to look dark to the south from here at the moment.