Storms 20/12/2019

[NZstorm]

I can't see any comments on Fridays trough. 500mb -28C surface dp 8C over Canterbury, good thermodynamic mix for lightning/hail.

[NZ Thunderstorm Soc]

I can't see any comments on Fridays trough. 500mb -28C surface dp 8C over Canterbury, good thermodynamic mix for lightning/hail.

Yes. CWU have a good chance of severe thunderstorm activity over the region on Friday as what I observed the other day.
I haven't joined them yet but if things go all-right I might have to subscribe to their website.

[TonyT]

I can't see any comments on Fridays trough. 500mb -28C surface dp 8C over Canterbury, good thermodynamic mix for lightning/hail.

Best chance would be with the surface wind-change, and thats going to be late morning/lunchtime, so unless that changes the chances of severe storm development are weak at best. Worth keeping an eye on, but not a strong day for Christchurch southwards based on current guidance. Might be a good day for a Marlborough/Wellington storm.

[Richard]

I can't see any comments on Fridays trough. 500mb -28C surface dp 8C over Canterbury, good thermodynamic mix for lightning/hail.

And its been in the models consistently for the last 10 days too. A bit more rain Friday hopefully on top of the 4mm from last evenings weak storm.

[NZstorm]

Looks like tomorrows front should produce a little bit of lightning over the west of the North Island as well.

[Chris W]

Looks too NW for thunder over Canterbury, MetService going low risk. Also don’t know if there’s enough time for an NE to get going. Still, I’d love to be wrong.

[tornado]

I see moderate risk for thunder in auckland tommorow. I hope for some thunder and lightning but I have a feeling there wont be any thunder at all. but I still have some hope....

[NZ Thunderstorm Soc]

Looks too NW for thunder over Canterbury, MetService going low risk. Also don’t know if there’s enough time for an NE to get going. Still, I’d love to be wrong.

All depends on timing.
Lots of activity going on in the SW corner of the SI at the moment according to the Blitz.
Probably fade out and the southerly change over Canterbury will be like the other day.

[Chris Raine]

Two distant rolling claps of thunder at Thornbury. Pressure now down to 983.7 hpa .Falling rapidly last three hours Had 19.2mmm of rain since 3pm

[NZstorm]

Queenstown has got thunder. Tekapo should get it as well.

[NZ Thunderstorm Soc]

Looking bleak in that direction from here.
One or 2 sferics from here.
Hope the Rangitata headwaters don't get another dowsing.

[Richard]

Great to see the storm risk has been increased for northern parts of Canterbury

[Chris W]

Wind has just picked up in Lyttelton, a solid roar for about half a minute there.

[NZ Thunderstorm Soc]

Great to see the storm risk has been increased for northern parts of Canterbury

Could get a clap or 2 judging by the lightning flashing away to the west at the moment.

[Chris Raine]

Anything John?.Was an elevated storm this end

[Richard]

Great to see the storm risk has been increased for northern parts of Canterbury

Could get a clap or 2 judging by the lightning flashing away to the west at the moment.

Stayed out west, but lit the bedroom up a few times.

Well then, what will today bring

[mikestormchaser]

I can't see any comments on Fridays trough. 500mb -28C surface dp 8C over Canterbury, good thermodynamic mix for lightning/hail.

I had been keeping eye on it, but yesterday looking at models it changed abit for the worse i think timing is an issue for us today and alot of the surface moisture points more towards inland north Canterbury? I think a low risk but Hope im wrong, its not best looking set up. Maybe a gust front, if anything happens hopefully it can hold off until lunch or bit later as i might be finishing early on this last day of work for the year and i can head out!

[Richard]

If you head up this way Mike let me know, could team up. I put off shopping today to be near home

[tornado]

I see theres a thunderstorm at taranaki right now. lets see what the front brings us this afternoon.


edit : moderate risk reduced to low for auckland. I declare a thunderstorm draught
last december was much better.

[Chris W]

I can't see any comments on Fridays trough. 500mb -28C surface dp 8C over Canterbury, good thermodynamic mix for lightning/hail.

I had been keeping eye on it, but yesterday looking at models it changed abit for the worse i think timing is an issue for us today and alot of the surface moisture points more towards inland north Canterbury? I think a low risk but Hope im wrong, its not best looking set up. Maybe a gust front, if anything happens hopefully it can hold off until lunch or bit later as i might be finishing early on this last day of work for the year and i can head out!

I also thought yesterday it looked more like a gust front at the coast around lunchtime then the showers head inland. Should be some heavy ones there though, seems there's plenty moisture for inland parts of North Canterbury and as mentioned cold air aloft.

[Richard]

Today's Moderate risk of storms looks similar to Wednesday inland convergence that saw one weak cell develop, today will be a lot more vigorous extending further to the SW along the inland Canterbury and up into the Marlborough and Wellington districts.

Issued at 8:43am Friday 20 Dec 2019

Valid to Midnight Friday 20 Dec 2019

A front is expected to move northeast across the upper North Island today. There is a moderate risk of thunderstorms associated with it this morning in Taranaki. Those storms may be accompanied by heavy rain, 10 to 20mm per hour and strong wind gusts, 90 to 110 km/h. The risk with the front is also considered moderate this afternoon and into the evening in the far east of the Bay of Plenty and the far north of Gisborne. The storms there may be accompanied by strong wind gusts, 90 km/h and heavy rain, 10 to 20mm per hour.

The front is followed by a cold unstable airmass that spreads north over the country. There is a generally low risk of thunderstorms across much of the South Island, but it is moderate over central and northern Westland, Buller and western Nelson in the afternoon and early evening, before easing. These thunderstorms could be accompanied by localised heavy rain with intensities of 10 to 15mm per hour and small hail.

About inland south Canterbury, North Canterbury and eastern Marlborough, the risk of thunderstorms increases to moderate for a time this afternoon and evening, associated with inland convergence and a southerly change. There is also a moderate risk of thunderstorms with the southerly change in Wellington, Kapiti and the south of Wairarapa late this afternoon and into this evening. If these thunderstorms occur, they may be accompanied by localised heavy rain with intensities of 10 to 15mm per hour and hail of 5 to 15mm in diameter.

There is a low risk of thunderstorms later this evening with the southerly change in Whanganui, Manawatu and the Tararua District These storms may be accompanied by hail.

No thunderstorms or severe convection expected elsewhere in New Zealand during this period.

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[Razor]

I'm not expecting any real action here today, strong NW is killing any fun I reckon. Happy to be proven wrong though

[Richard]

First promising sign of development

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[Chris W]

Radar is getting active behind the front, especially inland.

I also see signs of TCu from Amberley, nearly overhead.

[Richard]

Building fast now

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