Thunderstorms Upper North Island - April 19th - 22nd

seej · Unread post by **seej** » Sun 21/04/2013 20:12

I think the main rain band may take a lot longer to come ashore than anticipated.

cbm · Unread post by **cbm** » Sun 21/04/2013 20:14

The second storm of today, heading away to the Southeast about 5pm

treetop · Unread post by **treetop** » Sun 21/04/2013 20:28

weak T storm just passed west of Tauranga looks like that could be it now for a while ,moons out !

spwill · Unread post by **spwill** » Sun 21/04/2013 20:47

The line in the west is looking weaker now.

ben g · Unread post by **ben g** » Sun 21/04/2013 20:48

It's teasing us. Bound to cross us at some point, don't think I will sit up waiting tho. Will probably be best show for years and I will sleep through it.

jamie · Unread post by **jamie** » Sun 21/04/2013 20:57

Just saw a flash to the west. Raining here.

ben g · Unread post by **ben g** » Sun 21/04/2013 21:04

I recon that lightening active cell to the NW has us in our sights. Easy on the radar refresh button, the extra power output seems to kill them..

bmo · Unread post by **bmo** » Sun 21/04/2013 21:10

Just heard very loud rumble, hopefully the first of a few to come

NZstorm · Unread post by **NZstorm** » Sun 21/04/2013 21:13

Just spoke to the metservice guys the Whenuapai sounding indicated around 2300 j/kg of CAPE @ 00z.

My thinking today is 500j/kg to 800j/kg for Auckland Waikato. That's still very good instability.

jamie · Unread post by **jamie** » Sun 21/04/2013 21:20

seej wrote:Sorry guys for my ignorance, but what is CAPE?

Long story short it stands for convective available potential energy and is what fuels thunderstorms. NZ usually have a few hundred. In the tropics and thundery places it is in the thousands like today was here.

NZstorm · Unread post by **NZstorm** » Sun 21/04/2013 21:24

For CAPE of 2300j/kg you need to go to Darwin or USA. The tornado alley loaded gun soundings are a classic for the big CAPE numbers.

Tornado Tim · Unread post by **Tornado Tim** » Sun 21/04/2013 21:30

NZstorm wrote:For CAPE of 2300j/kg you need to go to Darwin or USA. The tornado alley loaded gun soundings are a classic for the big CAPE numbers.

It was confirmed that today's whenuapai sounding @ 00z was at least 1700 j/kg (SFC based).
MU CAPE was still a significant 900j/kg.
I wasnt so sure about the metservice figure, hence why I did a double check.

NZstorm · Unread post by **NZstorm** » Sun 21/04/2013 21:47

The sounding packages at both Wyoming and Plymouth State Universities use mixed layer CAPE. Mixed layer CAPE accounts for mixing and takes the mean dp in the lowest 100mb.

Wyoming has the NZWP 00Z CAPE at 633j/kg.

NZstorm · Unread post by **NZstorm** » Sun 21/04/2013 21:51

just add that CAPE is just a theoretical number and highly fluid. I tend to use the mixed layer numbers as this is commonly used in USA storm chasing. Although the RUC model does use best CAPE.

Tornado Tim · Unread post by **Tornado Tim** » Sun 21/04/2013 21:58

Yes Mixed Layer CAPE is best, but forecasting systems such as the GFS only output a SFC based value.
So in terms of a GFS confirmation you match types with types otherwise its unfair.

But even so 1700j/kg SFC based is very impressive for NZ

NZ Thunderstorm Soc · Sun 21/04/2013 22:25

Peopled_Diagram wrote:I did look out for you Brian!

But OMG you chose to go shopping instead of chasing!!! Oh for shame (wink).

I like that

Michael · Unread post by **Michael** » Sun 21/04/2013 22:31

Well get all ours tomorrow with the westerly change.

bmo · Unread post by **bmo** » Sun 21/04/2013 22:37

Very nice lightning display in the distance, takes 40-50 seconds for the sound to get to us

seej · Unread post by **seej** » Sun 21/04/2013 23:03

Thunder heard here now. This lightning tracker seems to be picking a few things up in north Auckland http://nzapstrike.net/live.php

Manukau heads obs · Sun 21/04/2013 23:13

yup, good ligthning and thunder and heavy rain here...woke me up....
21mm here so far for the day

David · Unread post by **David** » Sun 21/04/2013 23:23

Hope we get some good heavy rain to cool things down... muggy as tonight 18C dewpoint!

seej · Unread post by **seej** » Sun 21/04/2013 23:28

Lightning has unfortunately stopped for now. Moderate rain here now. No wind. Warm with lots of mozzies!

seej · Unread post by **seej** » Sun 21/04/2013 23:29

No sooner than I posted that, rain has become torrential.

seej · Unread post by **seej** » Sun 21/04/2013 23:38

Still torrential

seej · Unread post by **seej** » Sun 21/04/2013 23:44

Intracloud lightning above us. Obscured by rain.

NZ Weather Forum

Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 21st

Re: Thunderstorms Upper North Island - April 19th - 21st

Re: Thunderstorms Upper North Island - April 19th - 21st

Re: Thunderstorms Upper North Island - April 19th - 21st

Re: Thunderstorms Upper North Island - April 19th - 21st

Thunderstorms Upper North Island - April 19th - 21st

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 21st

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd

Re: Thunderstorms Upper North Island - April 19th - 22nd