Trough to end week

Archive of NZ Weather & Climate
Forum rules
These topics are a read-only archive and may be subject to out-of-date information.

For today's weather discussion head to: New Zealand Weather & Climate
User avatar
NZstorm
Posts: 11333
Joined: Mon 10/03/2003 19:38
Location: Grey Lynn, Auckland
Has thanked: 342 times
Been thanked: 361 times

Trough to end week

Unread post by NZstorm »

Looks like the front crossing northern NZ Friday has some convective potential due to moisture advection ahead of it. Thunderstorms/localised heavy falls look possible from Northland to Auckland through to Bay of Plenty/Taupo. Something to watch.

The southerly change over the east of the South Island later tomorrow is worth watching for convective potential.
C-Nimbus
Posts: 692
Joined: Tue 20/01/2004 13:22
Location: Waitakere City - Westie!!
Has thanked: 0
Been thanked: 0

Re: Trough to end week

Unread post by C-Nimbus »

Yes fridays setup looks encouraging. I have been on the east coast (hawkes bay) this week and there has been a fair amount of sea-breeze type convection happening which is always a sign that daytime heating and its effect on convection aint to far away.

Go the greens..... :mrgreen:
User avatar
David
Posts: 7189
Joined: Sat 18/08/2007 21:02
Location: Howick, Auckland
Has thanked: 346 times
Been thanked: 543 times
Contact:

Re: Trough to end week

Unread post by David »

Damn! I'll be stuck inside for hours on Friday afternoon, for senior prizegiving :(
All our plants are being watered today as the ground is really dry, just 100mm rain so far this Spring. But - I must say the weather has been stunning today :smile:
Image
User avatar
NZstorm
Posts: 11333
Joined: Mon 10/03/2003 19:38
Location: Grey Lynn, Auckland
Has thanked: 342 times
Been thanked: 361 times

Re: Trough to end week

Unread post by NZstorm »

Damn! I'll be stuck inside for hours on Friday afternoon, for senior prizegiving
The dynamics go through early morning with that front, should be through AK by day break by the looks.

As is typical it will be touch and go with the thermodynamics but hopefully some cb blowups over Auckland. We need the surface moisture to increase. GFS is forecasting dps of around 13C to 14C for Auckland. Currently Norfolk Island has dp 16C, Raoul dp 13C. And forecast wind shear with this system will favour thunderstorm development.
User avatar
mikestormchaser
Posts: 2527
Joined: Sat 03/06/2006 20:11
Location: Rolleston, Canterbury
Has thanked: 164 times
Been thanked: 308 times

Re: Trough to end week

Unread post by mikestormchaser »

What about thunderstorms on Saturday? for Canterbury
Mike
Stormchasers.co.nz
User avatar
Storm Struck
Posts: 4545
Joined: Wed 17/11/2004 21:25
Location: Belfast Christchurch
Has thanked: 2 times
Been thanked: 123 times

Re: Trough to end week

Unread post by Storm Struck »

The change does at this stage look to be coming through rather early on Saturday now, although having said that the models have been all over the show this week for Saturday.
We need sufficient heating before the change and any time after midday is usually more favourable.
There could be a few heavy showers with the passge of the second front by afternoon/evening tomorrow as long as some heating is involved between the two lingering fronts.
Cheers
Jason.
Canterbury, home of good rugby and severe storms
NZ Thunderstorm Soc
Posts: 17290
Joined: Wed 12/03/2003 22:08
Location: Raukapuka Geraldine
Has thanked: 1287 times
Been thanked: 999 times

Re: Trough to end week

Unread post by NZ Thunderstorm Soc »

tornadoman18 wrote:What about thunderstorms on Saturday? for Canterbury
....doubt it, sorry :-( q-

JohnGaul
NZTS
JohnGaul
NZThS
User avatar
NZstorm
Posts: 11333
Joined: Mon 10/03/2003 19:38
Location: Grey Lynn, Auckland
Has thanked: 342 times
Been thanked: 361 times

Re: Trough to end week

Unread post by NZstorm »

GFS chart here for 6am tomorrow morning. Lifted index, 500mb winds, 500mb temps.

Shows a hint of instability with the front out to east of Northland/Auckland and a hint of instability out to sea in that upper trough. We would need higher dewpoints to get proper instability in that front, 13 to 14C won't do it by the looks.
You do not have the required permissions to view the files attached to this post.
jamie
Posts: 5857
Joined: Fri 25/02/2011 21:35
Location: Hamilton NZ
Has thanked: 22 times
Been thanked: 258 times
Contact:

Re: Trough to end week

Unread post by jamie »

Looks to be alot of moisture about today. It even looks like we could get a few drops shortly if things keep developing the way they are 8)
Manukau heads obs
Posts: 12305
Joined: Mon 10/03/2003 16:30
Location: West Coast Road, Manukau Peninsula, North Island
Has thanked: 0
Been thanked: 0
Contact:

Re: Trough to end week

Unread post by Manukau heads obs »

21oC here now, very nice

some good convection to the SE of me, which is creating some nice looking lenticular wave clouds :)
You do not have the required permissions to view the files attached to this post.
Image
Brian Hamilton, weather enthusiast. My weather dataEmail: [email protected]
spwill
Posts: 9407
Joined: Sun 29/06/2003 22:39
Location: Mt Eden Auckland
Has thanked: 472 times
Been thanked: 541 times

Re: Trough to end week

Unread post by spwill »

Looks like some heavy showers have developed to your SE Brian. On the humid side for the time of year, dewpoints 15C

Here's a pic of some Cu over Auckland
You do not have the required permissions to view the files attached to this post.
jamie
Posts: 5857
Joined: Fri 25/02/2011 21:35
Location: Hamilton NZ
Has thanked: 22 times
Been thanked: 258 times
Contact:

Re: Trough to end week

Unread post by jamie »

Just about to get nailed by some heavy rain. Cloud base just going over now and its sucking up alot of cloud. Cloud is starting to form as it gets sucked up at roughly the same height as the viewing deck of the sky tower.

Also looking out over Rangitoto it looks very dark and nasty. I think what we are about to get is a little leg comming off what i can see over Rangitoto.
User avatar
David
Posts: 7189
Joined: Sat 18/08/2007 21:02
Location: Howick, Auckland
Has thanked: 346 times
Been thanked: 543 times
Contact:

Re: Trough to end week

Unread post by David »

Was over in Botany between 4.15pm and 5.15pm - some very heavy rain there for a short time. Only 0.5mm here this afternoon, and 1.5mm between about 6 and 8am this morning.
Image
spwill
Posts: 9407
Joined: Sun 29/06/2003 22:39
Location: Mt Eden Auckland
Has thanked: 472 times
Been thanked: 541 times

Re: Trough to end week

Unread post by spwill »

There has been early evening Thunderstorms over the Mackenzie country down south and a weak storm over Kaipara north of Ak.
Manukau heads obs
Posts: 12305
Joined: Mon 10/03/2003 16:30
Location: West Coast Road, Manukau Peninsula, North Island
Has thanked: 0
Been thanked: 0
Contact:

Re: Trough to end week

Unread post by Manukau heads obs »

heavier showers showing up to the west of northland/auckland now on the rain radar :)
Image
Brian Hamilton, weather enthusiast. My weather dataEmail: [email protected]
User avatar
NZstorm
Posts: 11333
Joined: Mon 10/03/2003 19:38
Location: Grey Lynn, Auckland
Has thanked: 342 times
Been thanked: 361 times

Re: Trough to end week

Unread post by NZstorm »

early evening Thunderstorms over the Mackenzie country
yes, a bit of convergence down there between a WNW and the southerly flow.
heavier showers showing up to the west of northland/auckland now on the rain radar
yes front looks a little bit convective.
Manukau heads obs
Posts: 12305
Joined: Mon 10/03/2003 16:30
Location: West Coast Road, Manukau Peninsula, North Island
Has thanked: 0
Been thanked: 0
Contact:

Re: Trough to end week

Unread post by Manukau heads obs »

Holy moley, reports of a tornado in cambridge at 3am!!!
reports of 100 houses being damaged (mainly roof damage), but its still called a mini tornado by the media? :eek:
Image
Brian Hamilton, weather enthusiast. My weather dataEmail: [email protected]
User avatar
Storm Struck
Posts: 4545
Joined: Wed 17/11/2004 21:25
Location: Belfast Christchurch
Has thanked: 2 times
Been thanked: 123 times

Re: Trough to end week

Unread post by Storm Struck »

Interesting looking at the radars overnight which show a band of showers the NE of Christchurch running through Pegausus Bay and even heavy about the northern Foothills for a time.
Of course i recieved some bursts of showers here too this morning under a NE flow,any suggestions as to why this happend?.
Also some slight unstable skies again out there now with CU forms bubbling away, could be some showers inland later on perhaps.
Cheers
Jason.
Canterbury, home of good rugby and severe storms
tich
Posts: 3389
Joined: Sat 15/03/2003 18:32
Location: Christchurch (St Albans)/Akaroa
Has thanked: 16 times
Been thanked: 69 times

Re: Trough to end week

Unread post by tich »

Of course i recieved some bursts of showers here too this morning under a NE flow,any suggestions as to why this happend?.
This morning - you mean during daylight hours or before? Totally fine in Chch all today, after clearance of overnight cloud. (no precip. in city)
User avatar
David
Posts: 7189
Joined: Sat 18/08/2007 21:02
Location: Howick, Auckland
Has thanked: 346 times
Been thanked: 543 times
Contact:

Re: Trough to end week

Unread post by David »

Bit of a dull front for here, no particularly heavy rain nor thunder. A useful 14mm rain though - the ground is dry so more would have been preferable.
Image
User avatar
TonyT
Moderator
Posts: 2765
Joined: Thu 08/05/2003 11:09
Location: Amberley, North Canterbury
Has thanked: 325 times
Been thanked: 987 times

Re: Trough to end week

Unread post by TonyT »

tich wrote:
Of course i recieved some bursts of showers here too this morning under a NE flow,any suggestions as to why this happend?.
This morning - you mean during daylight hours or before? Totally fine in Chch all today, after clearance of overnight cloud. (no precip. in city)
9mm here between about 4am and 10am. Steady but never near heavy. Looked like cloud wrapped around the weak trough out to the east of the North Island.
borris89
Posts: 217
Joined: Mon 06/02/2006 21:21
Location: Havelock North, Hawkes Bay/ Dunedin, Otago
Has thanked: 0
Been thanked: 0

Re: Trough to end week

Unread post by borris89 »

currently very heavy shower passing over hastings and havelock north, a bit of thunder before but nothing special really.
User avatar
Storm Struck
Posts: 4545
Joined: Wed 17/11/2004 21:25
Location: Belfast Christchurch
Has thanked: 2 times
Been thanked: 123 times

Re: Trough to end week

Unread post by Storm Struck »

Southerly came through around 10am this morning strong and gusty at times, but no rain just a few spots.
Looks like the showers went more inland than anything, going to be a cool night anyway.
Just goes to show how much weather models change over time as the cold blast which it was showing for mid next week have completly pulled off the idea now, although some suggest a low to cross the North Island and upper South Island by the end of the week.
So far it is looking ok for Labour weekend as we all know we usually get severe weather on that weekend as has been seen in the past.
Cheers
Jason.
Canterbury, home of good rugby and severe storms
User avatar
NZstorm
Posts: 11333
Joined: Mon 10/03/2003 19:38
Location: Grey Lynn, Auckland
Has thanked: 342 times
Been thanked: 361 times

Re: Trough to end week

Unread post by NZstorm »

Looks like there will be a low pressure system affecting NZ later in the week. And yes, hopefully a fine Labour weekend.

There does look to be a low chance of isolated thunderstorms over northern Waikato/east Auckland hills tomorrow afternoon due to wind convergence as winds turn more into the E/NE while a west coast W sea breeze looks possible.
spwill
Posts: 9407
Joined: Sun 29/06/2003 22:39
Location: Mt Eden Auckland
Has thanked: 472 times
Been thanked: 541 times

Re: Trough to end week

Unread post by spwill »

Both GFS and ECMWF want to spoil the start of the holiday weekend with that Low.

The Coastal Classic Yacht Race (Auckland to Russel this friday) might be heading out into a very windy Hauraki Gulf.
Locked