Thunder, Squalls (13 to 14th April)

spwill · Unread post by **spwill** » Sun 12/04/2015 08:43

Perhaps thunder/hail as far north as South Auckland Mon night/Tues morn, depends how far north the very cold upper system reaches.

Tornado Tim · Unread post by **Tornado Tim** » Sun 12/04/2015 18:17

spwill wrote:Perhaps thunder/hail as far north as South Auckland Mon night/Tues morn, depends how far north the very cold upper system reaches.

Looks like the more colder air is below Bombay, might get a few Thundery showers though for South Auckland.

David · Unread post by **David** » Sun 12/04/2015 18:18

Tornado Tim wrote: Looks like the more colder air is below Bombay, might get a few Thundery showers though for South Auckland.

GFS is showing it dropping to about -23C at 500mb over Auckland, that still sounds cold enough for some thunder/hail for the time of year I would think. Well, I hope so anyway

NZstorm · Unread post by **NZstorm** » Sun 12/04/2015 19:57

David wrote:
Tornado Tim wrote: Looks like the more colder air is below Bombay, might get a few Thundery showers though for South Auckland.
GFS is showing it dropping to about -23C at 500mb over Auckland, that still sounds cold enough for some thunder/hail for the time of year I would think. Well, I hope so anyway

500 -23 will be no good David as the dps are only 7 or 8C tomorrow night.

Looks like 500mb -28C gets as far north as Port Waikato on both ukmet and gfs. SST are 19-20C.

NZ Thunderstorm Soc · Sun 12/04/2015 20:08

Can't wait for tomorrows thunderstorms

mikestormchaser · Unread post by **mikestormchaser** » Sun 12/04/2015 20:17

NZ Thunderstorm Soc wrote:Can't wait for tomorrows thunderstorms

Amen to this!

im just a wee bit worried if the timing of the southerly change. But heres hoping!

Manukau heads obs · Mon 13/04/2015 06:04

impressive looking front to hit here soon

jamie · Unread post by **jamie** » Mon 13/04/2015 07:00

Manukau heads obs wrote:impressive looking front to hit here soon

Looks great from here. Haven't seen a bubbling front like this in ages.

Manukau heads obs · Mon 13/04/2015 07:59

Approachcing front for auckland area lightning active currently
and looks like could be hail on it too going by rain radar

Tornado Tim · Unread post by **Tornado Tim** » Mon 13/04/2015 08:17

Looks like the front is indeed Lightning active in parts

NZstorm · Unread post by **NZstorm** » Mon 13/04/2015 08:20

A few lightning strikes detected on front out to west of Auckland. Lightning rate only about 1 per min though.

jamie · Unread post by **jamie** » Mon 13/04/2015 08:22

It has turned to mush over the Waikato but the part heading for Auckland looks rather juicy still.

Manukau heads obs · Mon 13/04/2015 08:24

The first squall ...was a lightning strike on this to my west picked up

NZstorm · Unread post by **NZstorm** » Mon 13/04/2015 08:35

The dp has come up to 14c as modeled.

Manukau heads obs · Mon 13/04/2015 08:38

We reached 18C here ahead of the front

mikestormchaser · Unread post by **mikestormchaser** » Mon 13/04/2015 08:53

A wee mistake by metservice here with the hail size in this short paragraph

150mm in diamter

uhhhh i think ill need insurance claim on the house if that happend lol ..."southerly change is forecast to move through eastern Otago, the Canterbury coast and Plains reaching Christchurch around evening, and the Kaikoura Coast. There is a moderate risk of thunderstorms with this change,producing brief heavy rain, strong wind gusts of 100km/h, and hail of 5-150mm. A lesser risk of isolated thunderstorms extends over inland Otago,and remaining parts of Canterbury and Marlborough.

Tornado Tim · Unread post by **Tornado Tim** » Mon 13/04/2015 09:00

mikestormchaser wrote:A wee mistake by metservice here with the hail size in this short paragraph 150mm in diamter uhhhh i think ill need insurance claim on the house if that happend lol ..."southerly change is forecast to move through eastern Otago, the Canterbury coast and Plains reaching Christchurch around evening, and the Kaikoura Coast. There is a moderate risk of thunderstorms with this change,producing brief heavy rain, strong wind gusts of 100km/h, and hail of 5-150mm. A lesser risk of isolated thunderstorms extends over inland Otago,and remaining parts of Canterbury and Marlborough.

Yup looks like a bit of a typo.

Anyway here is the full Thunderstorm Outlook for Peoples reference:

Metservice wrote: Two cold fronts, the leading one lying over Waikato this morning and the second over Taranaki, move quickly eastwards across the upper North Island to clear eastern Bay of Plenty during the evening. There is a moderate risk of thunderstorms with these fronts from north Taranaki to Waikato then east over Bay of Plenty and north to southern Northland. These thunderstorms are expected to accompanied by locally heavy rain, strong wind gusts of 90-110km/hr, small hail, and possibly a small tornado, most likely in coastal areas.

The risk of thunderstorms eases briefly, but then cold air in the upper atmosphere rolls over the lower and central North Island this afternoon and evening, bringing further heavy showers and hail. The risk of thunderstorms increases to high from Waikato to Wanganui,including western Bay of Plenty,Taupo and Taihape. These thunderstorms may produce brief heavy rain, strong wind gusts of 100km/hr and hail of 5 to 15mm diameter. A southerly change is forecast to move through Wellington, Kapiti and Wairarapa this afternoon, bringing a few heavy showers with hail, and a low risk of thunderstorms. The moderate risk of thunderstorms in Buller and western Nelson eases during the afternoon as winds there turn offshore.

Very unstable conditions persist over southern and eastern parts of the South Island. The moderate risk of thunderstorms continues over southern Fiordland,Southland, Clutha and eastern Otago through the afternoon, easing in the evening.These thunderstorms may produce brief heavy rain, small hail, and heavy snow above about 200 metres. A southerly change is forecast to move through eastern Otago, the Canterbury coast and Plains reaching Christchurch around evening, and the Kaikoura Coast. There is a moderate risk of thunderstorms with this change,producing brief heavy rain, strong wind gusts of 100km/h, and hail of 5-150mm. A lesser risk of isolated thunderstorms extends over inland Otago,and remaining parts of Canterbury and Marlborough.

Elsewhere, no thunderstorms or significant convection expected.

ben g · Unread post by **ben g** » Mon 13/04/2015 09:09

Looking west from west Akl

ImageUploadedByTapatalk1428872952.809922.jpg

Orion · Unread post by **Orion** » Mon 13/04/2015 15:10

Have seen a few "explosive-looking" clouds among those moving north along the coast here; such a pity the Rain Radar hasn't been available to confirm whether they're as interesting as they look.

RichyDunedin · Unread post by **RichyDunedin** » Mon 13/04/2015 15:33

Have had a few rumbles on and off in Dunedin during heavy hail showers today.

JamesNZCH · Unread post by **JamesNZCH** » Mon 13/04/2015 16:15

Had a decent sleety shower up on the port hills about an hour and a half ago (enough so send a tour group running back to their bus). There is some pretty nice cloud formations forming to the SW. It's a shame we can't get anything from the radar to see whats going on more, though i'm sure we will survive

The Canterbury foothills have a light dusting of snow on them too.

NZstorm · Unread post by **NZstorm** » Mon 13/04/2015 17:19

Great photo JamesNZCH.

Showery day here with 17mm recorded so far.

spwill · Unread post by **spwill** » Mon 13/04/2015 17:32

Latest GFS brings the very cold upper system further north so possible thunder and hail in some of the showers over the Auckland region overnight.

David · Unread post by **David** » Mon 13/04/2015 17:52

Nothing of interest here yet, 8mm of moderate showers. Down to 13C this evening.

Manukau heads obs · Mon 13/04/2015 18:11

good squall just through here now
56 kts (103kmh)
only 10C now
22mm of rain so far today here

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