Thunder possibilities 5-6th June, Northern NZ

[NZstorm]

Looks like there should be atleast a few rumbles across Northern NZ with this next system. The upper level air is not unduly cold though (which is definitely a negative in June) but there will be surface dps of 16-17C late Tuesday/Wednesday.

The thunder risks look moderated with tomorrows front due to the warm upper air (500mb -15C) but there looks like there should be atleast isolated storms, particularly in the BOP due to some upper level cooling occurring late in the day.

Wednesday looks like the highest risk day at this stage with the upper trough modelled to cross the North Island.

[NZstorm]

Looks like there is a good low level jet with tomorrows front too, 2000ft wind 50kts which points to strong squalls if convection does eventuate.

[Nev]

MS forecasting gusts to 50 kts (93 km/h) in the Gulf later today and 45 kts (83 km/h) in the Waitemata.

Here's this morns latest update (not much change)...

MetService - Severe Thunderstorm Outlook

Valid to: Midnight Tuesday 5 Jun 2012
Issued at: 8:13am Tuesday 5 Jun 2012

An active frontal system is expected to move across the North Island and upper South Island this afternoon and evening, bringing a burst of heavy rain to many places as detailed in the latest Severe Weather Watch and Warning. There is an associated moderate risk of thunderstorms this evening for Buller, northwest Nelson,northern Taranaki, coastal Waitomo, the north and east of Northland and Coromandel Peninsula, and for the Bay of Plenty. These thunderstorms may produce localised heavy rain and strong wind gusts of 90 to 110 km/h. A lesser risk of thunderstorms extends from Northland to Waikato and Taumarunui, also Kapiti, Wellington, northern Marlborough, and the remainder of Nelson as depicted on the chart. No thunderstorms expected over the rest of the country.

[Manukau heads obs]

lots of CBs have developed in the NW flow in the North tasman, which are going to roll down onto the upper NI, I see

[NZstorm]

The cooler upper air and forcing will spread onto the North Island today. I see there has already been a storm over the lower NI this morning.

The thunder risk for Auckland comes in this afternoon, just have to see what develops. Looks 50/50 for Auckland.
Nice mild morn with 15C.

[Manukau heads obs]

CB to my SW

[Nev]

This morns update looking more interesting...

MetService - Severe Thunderstorm Outlook

Valid to: Midnight Wednesday 6 Jun 2012
Issued at: 8:22am Wednesday 6 Jun 2012

Unsettled northwesterlies cover the central and upper North Island today. There is a moderate risk of thunderstorms from this morning for Northland, and for Auckland, Coromandel Peninsula and Bay of Plenty into the afternoon and evening. These thunderstorms may produce localised rainfall rates of 10 to 20mm/hr,strong wind gusts of 90 to 110 km/h, and the chance of a few small tornadoes. A lesser risk of thunderstorms extends from Waikato to Taranaki as depicted on the chart. In addition, a slow moving front lies near Wanganui, Manawatu and northern Nelson this morning and afternoon, bringing outbreaks of rain. There is a low risk of a few thunderstorms with this front.
No thunderstorms expected over the rest of the country.

[Manukau heads obs]

looks like snow thunder around Kaikoura occured...

[Nev]

Story about this morn's thunderstorm in Wgtn...

'Flooding on Wellington roads' - Dominion Post (Stuff)

[snowkitty]

We had some amazing thunderstorms early this morning. The first one woke me up at 3.45 am for about 30 minutes. The whole house lit up each time there was lightning and the thunder drove our cats wild. They woke me up again at about 5 am...

[jamie]

Just had 7mm in less than 5mins. Rain rate Got up to 200mm/h.

[Orion]

Just had 7mm in less than 5mins. Rain rate Got up to 200mm/h.

Amazing.
Hope the 'utilities' cope!

[Aucklandstorm]

Anyone see that distant lightning out west Auckland ?

[Manukau heads obs]

looks like a nice lightning active CB in the north waikato at the moment
http://www.blitzortung.org/Webpages/ind ... bpage_0=21
matches an intense cell on the rain radar

I see there is a new line to come in from the west...might fire up

[jamie]

Yup good lightning an thunder here!!!

[jamie]

Amazing lightning. It's lighting up the entire sky and area.

[jamie]

Dang it's getting so active. Every 10 seconds or so

[jamie]

still really active. sparked up just after it passed over us. Its now a decent band on the rain radar. We even had sporadic drops of hail a few minutes ago.

[Tornado Tim]

yes a fairly good thunderstorm here One to the south east of me around Cambridge and one to the north by Jamie.

[Manukau heads obs]

dang, I did look out to my SE for lightning, but must have looked just before it got active again...I might have been able to see if too as it was clear between here and the north waikato (well I could see stars anyway)

[Thunder]

Has looked good for thunderstorms up there this evening, good stuff.