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Intense Tasman Low - Nov 24-26

Posted: Sun 22/11/2020 14:48
by tornado
Thought I will make a thread for next week's low.

Hopefully it can bring us more rain and thunder too .

Re: Intense Tasman Low - Nov 24-26

Posted: Mon 23/11/2020 15:05
by tornado
Looks like 30mm for Auckland and heavy totals for central north island. . Flood risk .

Re: Intense Tasman Low - Nov 24-26

Posted: Mon 23/11/2020 15:51
by Cyclone Tracy
EC's 18Z run upgrading around Auckland to 40 to 60mm for the thread which is looking similar to the UK 12Z run.

Re: Intense Tasman Low - Nov 24-26

Posted: Mon 23/11/2020 16:01
by Cantab03
Every run seems to have this low more and more further north. Not expecting more than about 10mm here in Christchurch.

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 07:33
by NZstorm
Rainfall from the warm front in the next 24hours for the Auckland region according to 12Z EU.

Some cooling upper air tomorrow means a few squally thunderstorms could develop over the North Island given the high dewpoints.
GFS shows a cold front crossing from the middle of the day.

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 08:03
by Cyclone Tracy
Upper polar low over the Antarctic shelf launching the injection streamer into the west side of the Tasman low with a warmer moist jet to the east side.

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 10:44
by Awhituobs

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 12:03
by Nev
Already over 8mm here in the last hour.

Yes, MS T-storm Outlook for tomorrow looks interesting…

MetService T-storm Outlook maps for Nov 22.png

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 12:19
by Awhituobs
the cold front in the north tasman has exploded...very lightning active :)

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 13:14
by spwill
We will have a cool maximum temperature here today, currently 16C, overcast light rain

Humid weather here tomorrow with cool upper levels, see what weather action can happen.

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 15:40
by tornado
Yes tommorow look good for thunder. 3mm here so far.

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 15:45
by Awhituobs
are you sure your rain gauge is correct?
3mm here and 2mm at Ricky's place in general rain from high based clouds

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 15:48
by tornado
Awhituobs wrote: Tue 24/11/2020 15:45 are you sure your rain gauge is correct?
3mm here and 2mm at Ricky's place in general rain from high based clouds
I meant 3mm oops I will change that.

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 16:59
by David
Why did I just hear on the radio them saying a storm is coming with possible power cuts and the most rain in one go since April 2017??? Seems pretty irresponsible

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 17:05
by Nev
Up to 15mm here since 11am…

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 17:14
by Nev
David wrote: Tue 24/11/2020 16:59 Why did I just hear on the radio them saying a storm is coming with possible power cuts and the most rain in one go since April 2017??? Seems pretty irresponsible
Partly based on a tweet from MS it seems… :-s

https://twitter.com/MetService/status/1 ... 8626902018

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 18:28
by tornado
David wrote: Tue 24/11/2020 16:59 Why did I just hear on the radio them saying a storm is coming with possible power cuts and the most rain in one go since April 2017??? Seems pretty irresponsible

Probably referring to the metservice tweet and outlook for squally thunderstorms tommorow. I expect localised powercuts and downpours with thunder and Gusty winds at least

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 18:53
by ScottyD
David wrote: Tue 24/11/2020 16:59 Why did I just hear on the radio them saying a storm is coming with possible power cuts and the most rain in one go since April 2017??? Seems pretty irresponsible
Just read the NZ Herald article saying the same thing. “ There was also expected to be up to 25mm of rainfall in one hour which would be the biggest fall since April 2017“. 🤦‍♂️

https://www.nzherald.co.nz/nz/wild-weat ... AEWOMZLBY/

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 21:24
by tornado
I see now high risk south of Auckland tommorow afternoon. Moderate Auckland morning to late afternoon for storms.

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 23:01
by NZ Thunderstorm Soc
tornado wrote: Tue 24/11/2020 21:24 I see now high risk south of Auckland tommorow afternoon. Moderate Auckland morning to late afternoon for storms.
Yes. it looks as though that you will experiencing a rather stormy period with this low. Some periods of rain which haven't been seen for a while.
Looking forward for the drizzle, here tomorrow. :crazy:
Today was another cloudy day with NE winds and a maximum of 18.2C here.

Re: Intense Tasman Low - Nov 24-26

Posted: Tue 24/11/2020 23:34
by Tornado Tim
Wheewy!

EC (usually conservative in its CAPE calculation) is chucking some serious numbers round the Waikato (1700j/kg), although CAPE is terribly fluid ;)

Certainly some moisture laden air coming our way with quite high precipitable water values.

Upper air is fairly cool around -14 to -15 degree region tomorrow afternoon.

Looking forward to some Lightning! :D

Re: Intense Tasman Low - Nov 24-26

Posted: Wed 25/11/2020 05:52
by David
Temperature up to 18C this morning. Only 4mm rain overnight, less than forecast which is disappointing. Fingers crossed for some decent falls today!

Re: Intense Tasman Low - Nov 24-26

Posted: Wed 25/11/2020 07:16
by treetop
lightning strikes picking up west of Hamilton now. not good chase weather with all this low cloud around. Best action likely between Raglan across to East cape,coastal tornado Eastern BOP ?

Re: Intense Tasman Low - Nov 24-26

Posted: Wed 25/11/2020 07:24
by Awhituobs
the cold front and clearence is coming in fast according to the sat image
interestingly my Air Pollution reading has incresed as the wind has gone more northerly....and I know that salt spray affects it..so it likely a pre cursor warning of a sudden NW change coming
big temperature rise here overnight with that warm front too :)
28mm here so far in total
now my wettest November on record!, 186mm

Re: Intense Tasman Low - Nov 24-26

Posted: Wed 25/11/2020 07:46
by NZstorm
Dewpoint 18C now with low stratus but can see patches blue sky. Hopefully some good heating this morning.