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Troughs and Possible Storms- Sep 25-30

Posted: Fri 23/09/2016 10:24
by Tornado Tim
Looking at several models, it seems we are entering into an extended period of rather interesting weather next week with a trough forecast to be stuck in place over the North Island for a few days.

If this forecast remains, we are most probably going to see the first spring/summertime convection setup. With unduly cold temps forecasted next week, could well be very interesting.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Fri 23/09/2016 21:25
by Richard
Looking even possibly unstable for inland areas of the SI Wednesday too.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sat 24/09/2016 07:51
by NZstorm
Great to see a system there for a week providing thunder chances.

I may go for a drive north tomorrow. Upper levels are looking good, comes down to surface parameters.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sat 24/09/2016 08:37
by spwill
At this stage Monday afternoon over Northland might be interesting, frontal Junk has moved out the way with some very moist air in sunshine.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sat 24/09/2016 10:54
by NZstorm
spwill wrote:At this stage Monday afternoon over Northland might be interesting, frontal Junk has moved out the way with some very moist air in sunshine.
I think this will happen Sunday afternoon. 12Z Ukmet was showing drier air aloft over Northland tomorrow pm.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sat 24/09/2016 17:53
by spwill
See how it looks in the morning, GFS showing warm humid air mass over northern NZ tomorrow.
dewpoint forcaste pm

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sun 25/09/2016 10:03
by NZstorm
Thunderstorm chances over Northland today look highly conditional on surface heating.
18C will produce about 250 CAPE whereas 20C will yield about 500+ CAPE.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sun 25/09/2016 11:47
by spwill
Northland catching some sunshine now, Whangarei on 20C.

Troughs and Possible Storms- Sep 25-30

Posted: Sun 25/09/2016 13:50
by jamie
Looks like a line between kaipara harbour and whangarei

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sun 25/09/2016 16:18
by Manukau heads obs
looks like a low center passing right over us here...going by rain radar
50mm or so here

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sun 25/09/2016 18:11
by Richard
Been getting some good steady rain here most of the afternoon

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sun 25/09/2016 18:30
by Manukau heads obs
we are stuck in a rain band that keeps on forming right over the top of us..
60mm here now total

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sun 25/09/2016 19:17
by NZstorm
Went for a drive to Kaiwaka this afternoon and observed tropical style downpours but non thundery.

I see the Pinnacles on the EW site has had over 200mm last 24hrs.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sun 25/09/2016 19:18
by Manukau heads obs
67mm or so here now..it just wont stop..the last remaining rand bands are stuck in place...

Re: Troughs and Possible Storms- Sep 25-30

Posted: Sun 25/09/2016 20:22
by Manukau heads obs
looks like you should get more rain at times Richard over the next few days too

Re: Troughs and Possible Storms- Sep 25-30

Posted: Mon 26/09/2016 06:52
by NZstorm
Pinnacles showing 380mm for event now. The Coromandel is certainly a wet place!

Re: Troughs and Possible Storms- Sep 25-30

Posted: Mon 26/09/2016 06:53
by Richard
Manukau heads obs wrote:looks like you should get more rain at times Richard over the next few days too
Be so good if this light rain keeps up, was looking to kick the irrigation into gear anyday

Re: Troughs and Possible Storms- Sep 25-30

Posted: Mon 26/09/2016 07:00
by Nev
NZstorm wrote:Pinnacles showing 380mm for event now. The Coromandel is certainly a wet place!
Yes, 380mm for the 48 hrs to 6am this morn, with 300mm of that in the last 24 hrs... 8-o

Re: Troughs and Possible Storms- Sep 25-30

Posted: Mon 26/09/2016 21:11
by Tornado Tim
West Waikato poses the risk of storm tomorrow with the SFC NE and Easterly and broad trough of low pressure and cold upper level temps should see something pop up come mid-late afternoon.
No shear and easterly steer is somewhat weak, convection will be pulsy with potential slow storm movements.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Tue 27/09/2016 10:37
by David
NZstorm wrote:Pinnacles showing 380mm for event now. The Coromandel is certainly a wet place!
Approximately 700mm there in the past 7 days!

Re: Troughs and Possible Storms- Sep 25-30

Posted: Tue 27/09/2016 11:00
by Richard
:eek: wow thats a lot , dont know if we've had that in the last two years

Re: Troughs and Possible Storms- Sep 25-30

Posted: Tue 27/09/2016 12:32
by spwill
A sunny morning here, currently 18C, dewpoint 15C. Not looking like we will get convergence around here today but southern parts of the Auckland region may do.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Tue 27/09/2016 15:29
by jamie
The sky is quickly changing to my SW. The radar is showing development too.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Tue 27/09/2016 16:36
by spwill
Parts of South Auckland catching an afternoon shower.
Been a nice day here.

Re: Troughs and Possible Storms- Sep 25-30

Posted: Tue 27/09/2016 18:42
by NZstorm
Glaciated cb to south but no lightning recorded.

Grey Lynn 20C today.