General December Weather

NZ Thunderstorm Soc · Wed 30/11/2016 20:53

Looks like a cold start off for the first month of summer but things should warm up with a few thunderstorms for Canterbury

NZstorm · Unread post by **NZstorm** » Thu 01/12/2016 06:32

First official day of summer looking like a good one for Auckland, blue skies!

jamie · Unread post by **jamie** » Thu 01/12/2016 12:29

NZstorm wrote:First official day of summer looking like a good one for Auckland, blue skies!

Is it really? We have drizzle here currently

David · Unread post by **David** » Thu 01/12/2016 14:03

jamie wrote:
NZstorm wrote:First official day of summer looking like a good one for Auckland, blue skies!
Is it really? We have drizzle here currently

It was nice until late morning, but mostly cloudy skies since then

NZstorm · Unread post by **NZstorm** » Fri 02/12/2016 07:38

K index values for later today.

A lazy way of forecasting and not necessarily an accurate way to assess convective potential but k index values show where the best shower/thunder potential is. Numbers over 30 tend to be a good signal.

jamie · Unread post by **jamie** » Fri 02/12/2016 08:18

Western BOP and Eastern Waikato on Monday...... looks to be the most promising day for about the last 6 weeks for us. Looks like pulsy stuff tho but better than nothing

spwill · Unread post by **spwill** » Fri 02/12/2016 15:32

Thunder over the eastern NI ranges yesterday afternoon and again this afternoon.

NZstorm · Unread post by **NZstorm** » Fri 02/12/2016 17:42

jamie wrote:Western BOP and Eastern Waikato on Monday...... looks to be the most promising day for about the last 6 weeks for us. Looks like pulsy stuff tho but better than nothing

Yes Monday has been looking promising. I can't chase unless there is something close to Auckland due work. Pulse storms can be great for CG's though and looks cold enough for hail.

spwill · Unread post by **spwill** » Sat 03/12/2016 08:54

I see cloudiness as a weakness for Mondays set up however as always have to see how it looks on the day.

spwill · Unread post by **spwill** » Sat 03/12/2016 09:25

The weather pattern into December looks more anticyclonic/less westerly influence than we saw in November.

jamie · Unread post by **jamie** » Sat 03/12/2016 17:43

Sea breeze just kicked in here. Stunning day

Richard · Unread post by **Richard** » Sat 03/12/2016 17:48

Must have been a huge downpour in Amberley Thursday morning going by the amount of flooding when we drove through, TonyT have you heard how much fall?

cbm · Unread post by **cbm** » Sat 03/12/2016 20:30

jamie wrote:Sea breeze just kicked in here. Stunning day

Sea breeze had started by 12:30pm out at Manu Bay Raglan. Got back in very early as all fish bins were full. Not sure it reached Cambridge all day, was back by mid afternoon, still and warm right through till now.

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jamie · Unread post by **jamie** » Sat 03/12/2016 21:13

cbm wrote:
jamie wrote:Sea breeze just kicked in here. Stunning day
Sea breeze had started by 12:30pm out at Manu Bay Raglan. Got back in very early as all fish bins were full. Not sure it reached Cambridge all day, was back by mid afternoon, still and warm right through till now.

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I was at the beach at raglan until 1pm. There was a weak sea breeze when we left at 1pm.

Friends out fishing also had a great day further up the coast and caught some very decent snapper

melja · Unread post by **melja** » Sun 04/12/2016 08:05

Richard wrote:Must have been a huge downpour in Amberley Thursday morning going by the amount of flooding when we drove through, TonyT have you heard how much fall?

We had 16mm in Rangiora but the flooding in Amberley was from more than that.

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Richard · Unread post by **Richard** » Sun 04/12/2016 08:25

melja wrote:
Richard wrote:Must have been a huge downpour in Amberley Thursday morning going by the amount of flooding when we drove through, TonyT have you heard how much fall?
We had 16mm in Rangiora but the flooding in Amberley was from more than that.

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Yes, there would have been a lot lot more than that going by the amount of water. Going south on SH1 just out of Amberley 200m south of the bakery on the opposite of the road there are some low areas on the side of the road, these were completely full of water, it would take 50mm+ to full them.

NZstorm · Unread post by **NZstorm** » Sun 04/12/2016 08:28

Tomorrows convection chances hinge on moisture advection (dewpoints 14C) on to the North Island from the west.

Looking like a warm week ahead for the North island. Grey lynn got to 24C yesterday and I can see 25C readings occurring this week.

spwill · Unread post by **spwill** » Sun 04/12/2016 09:00

Today looks a lovely day for Auckland, just enough southwest breeze to keep any sea breeze convergence away.

TonyT · Unread post by **TonyT** » Sun 04/12/2016 13:54

Richard wrote:Must have been a huge downpour in Amberley Thursday morning going by the amount of flooding when we drove through, TonyT have you heard how much fall?

I had 27mm, and most of that fell in under 3 hours, from a little before 6am till around 8.20ish. That area around Dock creek in the middle of Amberley is notorious for flooding, but it quickly subsided.

Richard · Unread post by **Richard** » Sun 04/12/2016 17:09

TonyT wrote:
Richard wrote:Must have been a huge downpour in Amberley Thursday morning going by the amount of flooding when we drove through, TonyT have you heard how much fall?
I had 27mm, and most of that fell in under 3 hours, from a little before 6am till around 8.20ish. That area around Dock creek in the middle of Amberley is notorious for flooding, but it quickly subsided.

Heard from someone who lives right in town who had 60mm which i would believe going by the amount of water

Manukau heads obs · Sun 04/12/2016 18:42

I was at the beach at raglan until 1pm. There was a weak sea breeze when we left at 1pm.

Friends out fishing also had a great day further up the coast and caught some very decent snapper

My sister and partner went fishing over the Waikato Bar
there boat capsized on the way back in , in the afternoon
luckily they were wearing life jackets and another boat was near to pluck them out of the water!

Orion · Unread post by **Orion** » Sun 04/12/2016 19:31

Manukau heads obs wrote: My sister and partner went fishing over the Waikato Bar
there boat capsized on the way back in , in the afternoon
luckily they were wearing life jackets and another boat was near to pluck them out of the water!

Glad no great harm done.

NZstorm · Unread post by **NZstorm** » Sun 04/12/2016 19:41

I have highlighted the convergence lines over the North Island tomorrow according to gfs. 7pm chart.

Central areas looking best placed for storms tomorrow.

cbm · Unread post by **cbm** » Sun 04/12/2016 19:50

Manukau heads obs wrote:
I was at the beach at raglan until 1pm. There was a weak sea breeze when we left at 1pm.

Friends out fishing also had a great day further up the coast and caught some very decent snapper
My sister and partner went fishing over the Waikato Bar
there boat capsized on the way back in , in the afternoon
luckily they were wearing life jackets and another boat was near to pluck them out of the water!

Sorry to hear that. As West Coast days go it was very flat. But even a 1m swell can capsize a boat if you get caught by it in the worst way. Lucky down here can access the West Coast without needing to cross a bar or surf launch.

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Tornado Tim · Unread post by **Tornado Tim** » Sun 04/12/2016 20:32

GFS === Absolute Truth

Convergence zones on that model I have found extremely unreliable if run on a more coarse grid.
The ECMWF model data backs GFS guidance somewhat to a certain extent, but convergence progresses and subsequently weekens further west into the evening in central Waikato. (GFS has none).
Easterly to North Easterly Seabreeze will be something to lookout for.

Instability numbers despite being fairly high for New Zealand, I find teters a little too close to the wind (excuse the pun).
Both subsequent models reveal a quite a close correlation on both instability being tied to that convergence and the assoc moisture that will be coming on the change in order for the parcel to turn unstable from surface.

Bay of Plenty I believe holds best chance of a pulsy storm with small hail, given favourable upper temps.

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