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Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 07:25
by NZstorm
Better had start the weekend with a thread dedicated to this weekends convection. An unstable airmass across the North Island with isolated to scattered afternoon/evening thunderstorms Saturday and Sunday.
Some quite persistent thunderstorm activity probable in the west around Taranaki and Waitomo from later today into tomorrow from Tasman Sea activity coming onshore. Heavy falls of rain possible.
Isolated severe hail/wind possible.
500mb chart for 6pm today. Big upper level system coming onto NZ.
500mb.gif
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 07:56
by tornado
yes looks intresting alright. im hoping for a good storm.
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 08:21
by Nev
Very thick sea-fog rolled in here about an hour or two ago.
Also didn't get below 18C here overnight, with DP's currently around 19C.
Waiheke, Palm Beach Fog - Dec 7.jpg
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 08:28
by Awhituobs
yes, the warm start to summer continues
been over 2c above normal here last few days (24 hour average)
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 09:05
by Cyclone Tracy
EC 12Z is eyeing off -40c to -60c cloud tops mid to late afternoon around the convergence. MS now have a STW in place for parts of the upper NI.
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 09:08
by David
Quite cloudy here. Hopefully that burns off so we get some good heating going
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 09:12
by Nev
This morn's update from MS for later today looks promising…
MetService Thunderstorm Outlook
Valid to: Midnight Saturday 7 Dec 2019
Issued at: 9:06am Saturday 7 Dec 2019
A front embedded within an unstable northwest flow moves over the upper South Island this morning and afternoon, bringing heavy rain to some western areas as detailed in the latest Severe Weather Warning. A high risk of thunderstorms and SEVERE THUNDERSTORMS is associated with this front, with downpours of 25-40+ mm/h likely.
There is a general moderate risk of thunderstorms over many parts of the South Island as indicated on the chart. Any thunderstorms that occur may produce localised rainfall rates of 10 to 25 mm/hr, small hail, and strong wind gusts of 90 to 100km/h about western coastal areas. A low risk of thunderstorms extends over the remainder of the South Island for today.
Showers are expected to form over parts of the North Island, especially from Northland through Auckland, the Coromandel Peninsula, eastern Waikato, Bay of Plenty, Rotorua and the north of Taupo. There is a moderate risk that some of these may be thundery in the afternoon and evening, and a moderate risk of severe thunderstorms in Northland, Auckland and Coromandel Peninsula as well. These storms may be accompanied by heavy rain, 10 to 25mm per hour and possibly more as indicated on the SEVERE THUNDERSTORM WATCH.
A moderate risk of thunderstorms is also in place for Taranaki, particularly from this evening, while a broader low risk covers other western parts of the North Island as indicated on the chart.
MetService T-storm Outlook Map for Dec 07, Is. 9.06am.png
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 09:14
by spwill
David wrote: ↑Sat 07/12/2019 09:08
Quite cloudy here. Hopefully that burns off so we get some good heating going
Been a sunny morning this side of town but weak sunlight with all the smoke haze.
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 10:55
by Cyclone Tracy
Sun out here. 25c and the DP hovering around 19 to 20c. Smoke haze and plenty of sun on the ground north of Auckland on the 10.20am sat pic.
Sat image 10.20am.jpg
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 11:27
by tornado
got a heavy shower here at the moment
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 12:17
by David
Looks like we have convergence. Airport showing wind from the W, its N to NE here.
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 12:42
by Cyclone Tracy
Light N to NE here. Pockets of sunshine every now and then. Mid level moisture has increased over the last hour between Northland and the central NI
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 13:17
by cbm
Might be imagining but swear even when the sun is out everything looks off colour/ yellow today like an 80's photograph due to the smoke.
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Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 13:54
by Nev
Severe Thunderstorm Warning issued for the Wellsford area...
MetService Severe T-storm Warning Map - Dec 07, Is. 1.30pm.gif
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 13:59
by NZstorm
Yes, looks to be a decent storm Welsford way.
Also a cell firing over Kaimais according to tracker.
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 14:19
by David
Just caught a very brief downpour, only 1.4mm sadly. Fingers crossed more showers develop...
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 14:29
by Willoughby
GOES-17's GLM sensor picking up today's lightning quite nicely (though there appears to be a slight offset needed for satellite imagery to match lightning):
https://www.weathernerds.org/satellite/ ... ascatb=Off
That looks like a pretty significant thunderstorm near Collingwood.
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 14:55
by Cyclone Tracy
Cloud tops on those Northland cells have got up to around -60c at times. It's still NNE wind here, sun is out again. 120 km radar starting to pop again. Visually, clouds are starting to bubble north of Auckland where there is nothing on the radar.
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 15:22
by Cyclone Tracy
Just gone south westerly here.
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 15:50
by David
Still NNE here. But looks like nothing's happening
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 16:09
by jamie
Can hear distant thunder from that cell near me.
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Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 16:18
by Chris W
Would argue both islands for this, given severe storms today on the rainfall/wind thread and Metservice have a low risk of severe storms out for coastal Otago and Canterbury up to Chch for tomorrow afternoon and evening.
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 16:23
by Iloveweather
Crazy thunder and lightning here in Blenheim!
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 16:26
by tornado
why is there storms south and north of auckland but nothing in auckland? I am hoping for a better day tommorow. hopefully we can catch some storms with afternoon heating and the front tommorow night.
Re: Thunderstorms North Island December 7 and 8
Posted: Sat 07/12/2019 16:39
by David
tornado wrote: ↑Sat 07/12/2019 16:26
why is there storms south and north of auckland but nothing in auckland?
Was thinking the same. We have warmth and convergence today so not sure why nothing is happening... Quite often it only sparks north and south of us in these convective situations