Thunderstorms/heavy showers - Dec 10-11

[Storm Struck]

Some models are in favour for an upper trough crossing from the west on Sunday, converging with a NE and a later SW wind shift.
Others not too keen on surface moisture on the plains.
I'd give it a low risk with general showers on the plains possibly heavy for a brief period.

[TonyT]

Some models are in favour for an upper trough crossing from the west on Sunday, converging with a NE and a later SW wind shift.
Others not too keen on surface moisture on the plains.
I'd give it a low risk with general showers on the plains possibly heavy for a brief period.

Plenty of instability about the eastern SI on Sunday afternoon.

[Nev]

Didn't get below 18C here overnight, with RH on or near 100% - warmest and stickiest night since April.

This morning's T-storm update for later today certainly looks interesting...

MetService Thunderstorm Outlook

A large trough covers most of the country today. A low in this trough lies west of the South Island while a front moves onto the North Island. These features contribute to an unstable situation in many places.

Initially there is a low risk of thunderstorms about the west of the North Island and west and south of the South Island, but this spreads to a wider area during the morning and early afternoon, covering most of the North Island (except Wellington and parts of eastern Bay of Plenty and Gisborne) and the west, central and southern parts of the South Island.

There is a moderate risk of thunderstorms about Westland and northern Fiordland during most of the day, and these thunderstorms may be accompanied by localised heavy rain with intensities of 10 to 20 mm per hour and hail of 10 to 20 mm in diameter.

Also this morning, a moderate risk of thunderstorms develops about the north of Northland, possibly bringing localised heavy rain with intensities of 10 to 25 mm per hour and small hail. In the afternoon a moderate risk of thunderstorms develops over much of the rest of the North Island, as shown on the chart. Here, the thunderstorms may be associated with localised heavy rain of 10 to 25 mm per hour, strong wind gusts of 60 to 80 km/h and hail with diameters 5 to 15 mm. There is also a low risk that there could be severe thunderstorms with downpours of 25 to 40 mm per hour. In the Far North, the thunderstorms should ease late afternoon or early evening, but continue longer into the evening further south.

For the southern Canterbury Plains, North Otago, Dunedin, parts of Central Otago and Southland there is a high risk of thunderstorms this afternoon and evening. These thunderstorms may be accompanied by hail of 5 to 15 mm in diameter and localised heavy rain of 10 to 25 mm per hour, or possibly more.

MetService Thunderstorm Outlook Map - Is. 10 Dec 8.19am.png

Issued: 8:21am Sat, 10 Dec
Valid to midnight Sat, 10 Dec

[Richard]

Humid and warm with light east wind here in Milton this morning. Signs of building clouds inland.

[Richard]

Impressive burn off to the north.

20221210_105320288.jpg

[David]

Just hit 20C dewpoint

[spwill]

See how much sunshine we can get today, sunny spells here now, feels humid today.

[Richard]

Showers forming about the district now.

20221210_123119325.jpg

[Richard]

First of the thunder and rain just starting

[NZ Thunderstorm Soc]

Few red blobs on the radar down your way.
That burn-off photo looks as those it may of set off that bit of thunderstorm activity??

[Richard]

No the fire was well before the storms arrived
Ended up two storms north and south, sun now coming out, plenty of time yet for further development

[Nev]

A few more nice pics of this morning's controlled burn-off near Dunedin...

'Controlled burn sparks call-out' - Otago Daily Times

[NZ Thunderstorm Soc]

Thunder heard about 5 minutes ago from a development just to the SW of here.

[Richard]

A few more nice pics of this morning's controlled burn-off near Dunedin...

'Controlled burn sparks call-out' - Otago Daily Times

Thanks Nev, was a big fire.

Such interesting weather here in the south. Now in Lawrence sitting outside having an ale at the pub. Lots of storms around but not what I would call overly active. But still they keep coming

[darcyplumb]

Thunder heard about 5 minutes ago from a development just to the SW of here.

They look very impressive from Ashburton. Radar looks good too.

[NZ Thunderstorm Soc]

Such interesting weather here in the south. Now in Lawrence sitting outside having an ale at the pub. Lots of storms around but not what I would call overly active. But still they keep coming

A bit like that here to the south and along the Hunters Hills observed from my usual jaunt around the Downs.
Only 3 claps heard in the storm just to the south of us.

[David]

Just heard a distant rumble. Looking ominous to the west

[spwill]

Intense rain storm here, some thunder also.

[spwill]

Grey Lynn on 35.8mm during last hr, a very quick 30mm here and more to come on the radar.

[Storm Struck]

Some cells just inland from Temuka and near Rangitata going by the radar, MS have shifted the high risk into this area now.
There has been some weak CU forms up this end, instability numbers are there but no moisture.
Currently 26C here moderate gusty northerly, although radar is picking up a bug line so must be a surface SW coming in.
Tomorrow moisture numbers have increased for the plains so local convergences should produce at least a moderate risk.

[David]

Heaps of thunder from this cell going to my W/SW. Brief deluge for a few mins as well

[Nev]

Mod Note: Thought it was about time we had a thread for this weekend's T-storms, etc.

[ricky]

38mm last hour and up to 9mm/min rate

[NZ Thunderstorm Soc]

Mod Note: Thought it was about time we had a thread for this weekend's T-storms, etc.

Thanks for that Nev as there might be some more thunder around tomorrow as well
Re Jason (Storm Struck) posting above. Yes another thunderstorm developed and moved out of the 4 Peaks area towards Timaru. More active with the previous cell with some forks this time. Tried to record a lightning flash but to no avail. Use the video next time
Some impressive cloud forms from the cell. Wind now gone southerly.

[mikestormchaser]

Nothing planed tonight so going to head south with Aaron and go for a drive, see what happens when that surface southerly skirts up tonight. Chance of some lightning activity coastal fringes/ offshore birdlings flat sernario later.