Page 1 of 5
Convective period. 26-28 Nov
Posted: Sun 24/11/2013 15:47
by jamie
Time for a new thread I think.
This looks to start Tuesday with rich moisture being fed in and some very nice instability numbers showing up in the models. Still a lot of variation on the details as to be expected but the general consensus is that we should have an interesting few days.
Re: Convective period. 26-28 Nov
Posted: Sun 24/11/2013 15:51
by jamie
Metservice severe weather outlook talks about this system. Looks like we will get a nice drop of rain at the very least.
Re: Convective period. 26-28 Nov
Posted: Sun 24/11/2013 16:02
by Manukau heads obs
kewl
local year 10 camp though this week ..they wont be wanting rain /wind..never mind!
Re: Convective period. 26-28 Nov
Posted: Sun 24/11/2013 18:33
by NZ Thunderstorm Soc
Hopefully, this system will deliver some needed rain here in Canterbury. Things are starting to dry out around here.
Re: Convective period. 26-28 Nov
Posted: Sun 24/11/2013 20:55
by Storm Struck
It was looking good for Thursday in Canterbury this week for thunderstorms but has since pulled back
, just the usual much needed rain however I cant complain too much as Friday/Saturday/Sunday could be thunder/hail days for Canterbury still a fair way out yet though.
But this is what I was expecting a return to unsettled weather should bring us a damp start to summer and hopefully good storm chances over the xmas/ new year period.
Re: Convective period. 26-28 Nov
Posted: Mon 25/11/2013 07:10
by NZstorm
Needed rain for most of the country this week!
GFS CAPE forecast for tomorrow afternoon with 300mb jet stream winds. Upto 1200j/kg of mixed layer CAPE. Isolated severe hail could be possible tomorrow if we can get some decent low level convergence. Certainly will get some thunder anyway.
Re: Convective period. 26-28 Nov
Posted: Mon 25/11/2013 07:34
by jamie
Around Taupo could be a good spot for tomorrow. That looks to be where the convergence will be. Should be some rather decent storms.
Re: Convective period. 26-28 Nov
Posted: Mon 25/11/2013 09:01
by Tornado Tim
Good CAPE and LI Numbers, the upper flow is quite strong so yes, there is the potential for bigger hail
Id expect Metservice to have a Moderate risk of Severe storms at least......
Re: Convective period. 26-28 Nov
Posted: Mon 25/11/2013 09:10
by jamie
We have really been lacking the upper level support with the last couple of setups so im looking forward to this one.
500 wind.png
300 wind.png
A lot of boxes are being ticked.There is also some good convergence to help things trigger
sufrace wind.png
Also there are LI's of -5
Re: Convective period. 26-28 Nov
Posted: Mon 25/11/2013 09:25
by Manukau heads obs
check out
http://weather.niwa.co.nz/weathermap/Tw ... infall_Map
does a good job of showing rain bands sliding down the west coast here...typical for them to do that....before finally getting a better rain band later tomorrow sweeping down from the north
Convective period. 26-28 Nov
Posted: Mon 25/11/2013 11:24
by jamie
Metservice are going for a moderate risk of severe storms across about 95% of the north island tomorrow.
Re: Convective period. 26-28 Nov
Posted: Mon 25/11/2013 11:36
by Tornado Tim
jamie wrote:Metservice are going for a moderate risk of severe storms across about 95% of the north island tomorrow.
For future reference:
Metservice wrote:Daytime heating combined with a very humid air-mass is expected to lead to thunderstorms over many parts of the North Island tomorrow. There is a moderate risk of severe thunderstorms developing in the afternoon and evening around convergence zones in the low-level wind flow from about Hawkes Bay and Manawatu northwards as shown on the chart. Some of these thunderstorms may have rainfall rates of 40mm per hour and hail of diameter 10 to 20mm and wind gusts around 100km/hr. A low risk extends further southwards. The thunderstorms activity is expected to die away late evening as temperatures cool.
Elsewhere, no risk of thunderstorms or significant convection.
Re: Convective period. 26-28 Nov
Posted: Mon 25/11/2013 20:49
by NZstorm
We have really been lacking the upper level support with the last couple of setups so im looking forward to this one.
Yes, looking like some dynamics with this set up for a change. Jet stream looks well positioned to assist convection.
Mid level clouds clear out fairly quickly tomorrow so should get good heating. It would be good to get the NE sea breeze going.
Convective period. 26-28 Nov
Posted: Tue 26/11/2013 01:31
by jamie
03Stormchaser - have you changed your flights for a Thursday chase?
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 06:42
by NZstorm
Last time we had a thunderstorm set up like this was April 21.
With no capping today Thunderstorms will quickly develop inland this afternoon. Frequent lightning possible with a risk of isolated severe hail. The best convergence looks to be well south today. Storms will move SE 30km/h +. Unfortunately I won't be chasing today because of work commitments.
Tomorrow (Wednesday) the set up changes with the low level flow more E/NE which will put the best convergence in the west from Northland to Waikato. Hopefully that will verify.
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 07:34
by Manukau heads obs
I see the line of showers moving down the west coast here...just like that NIWA model had forecasted yesterday and which I noted would be typical
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 07:43
by NZstorm
While I won't be chasing today I will ofcourse be keeping a check on Auckland's weather. Wind at the airport looks positive with NE08kts.
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 07:46
by David
A low of 17.7C here overnight, hopefully the sun comes out and we get some nice heating
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 07:56
by Manukau heads obs
yes, NNE wind here
upper level clouds are more NNW
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 08:07
by jamie
The sun is beginning to poke through holes in the clouds here.
The next three days look great. Tomorrow looks to be more north and western which could make it a better day than today for us. On Thursday the 1pm LI's have a spot down to -7 which is something i haven't seen over NZ since these maps were introduced.
gfs.stormcast.bsch.init-2013112512z.fcst-201311281300z.li.nz.null.0.png
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 08:26
by Tornado Tim
Cells should be fairly tall today, the Trop is around 250hpa. Cells should linger around till 10PM. Hopefully a good light show.
I will chase today. Not entirely sure where I will head....Might meetup with Ricky. If I was in Aucky I would pick you up Dave.....
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 08:31
by Manukau heads obs
I could be up for a chase too...if north waikato...
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 08:37
by Tornado Tim
Simon, Snoopsta... Are you guys keen?
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 08:43
by jamie
I will chase anything that's in the area but don't think i can really go 'looking' for storms. Will see how things go anyway.
Re: Convective period. 26-28 Nov
Posted: Tue 26/11/2013 08:53
by jamie
Brian - the radar makes it look like there is a small, weak low that is heading your way. this might change your wind to a SW briefly if it moves north of you.
I get the feeling today will be more down taupo way for the best storms.
It does look good for night time lightning as Tim said.