Heavy rain & strong winds 31 Aug - 2 Sep

David · Unread post by **David** » Sun 30/08/2015 13:38

Much of the North Island and the top of the South Island look to be in the firing line for some heavy rain and/or strong winds early this week.

Issued: 2:48pm Saturday 29 Aug 2015
Valid from Monday 31 August 2015 to Thursday 3 September 2015

During Monday, a deepening low should approach northern New Zealand, then move southwards onto central New Zealand during Tuesday. An associated frontal system is likely to bring a period of heavy northeasterly rain to northern and central parts of the North Island, along with east to northeast gales. The heaviest rain is forecast from Northland to Bay of Plenty and northern Gisborne, and southwards to Tongariro National Park and Mount Taranaki, where there is moderate confidence of warning amounts of rain. Brief easterly rain brings a low risk of warning amounts during Tuesday from southern Gisborne to Wairarapa,as depicted on the chart.

As the frontal system moves southwards across the North Island, there is moderate confidence of east to northeast gales becoming severe for a time over western and central areas from Auckland to Kapiti, and over Nelson and Buller. The risk of severe gales reduces over Taupo and eastern Bay of Plenty.

As the low and frontal system moves onto central New Zealand during Tuesday, there is moderate confidence of warning amounts of rain for Marlborough and Nelson, easing into Wednesday. In addition, a period of westerly gales are possible for the lower North Island as the low moves past, and forecasters will monitor this.

During Wednesday, the low should move away to the east of the South Island, followed by a ridge of high pressure on Thursday.

http://www.metservice.com/warnings/seve ... er-outlook

David · Unread post by **David** » Mon 31/08/2015 06:45

a bit misty this morning, can hear fog horns in the distance... Must be ferries at Half Moon Bay

Richard · Unread post by **Richard** » Mon 31/08/2015 07:08

Surely this system can finally bring some rain to the drought areas of North Canterbury, fingers crossed.

NZstorm · Unread post by **NZstorm** » Mon 31/08/2015 07:22

Warm front moving onto Auckland now with a decent spell of rain this morning. Precip should ease after midday and return later. The cold front comes through early tomorrow morning with potentially some very heavy rain and non zero thunder risk. Also whenever you have moist air moving south you have the risk of a localised tornado.

Nev · Unread post by **Nev** » Mon 31/08/2015 07:25

David wrote:a bit misty this morning, can hear fog horns in the distance... Must be ferries at Half Moon Bay

Still pockets of low fog around here this morn. Most of last night looked like a combination of fog and light drizzle, which looked a bit weird under the full moonlight. Exactly 10mm here since late Saturday.

spwill · Unread post by **spwill** » Mon 31/08/2015 07:49

The Auckland dewpoint yesterday was around 15C so not much cooling required for fog, min temp overnight around 13C.

Manukau heads obs · Mon 31/08/2015 07:54

'non zero thunder risk'
love it, LOL

David · Unread post by **David** » Mon 31/08/2015 18:02

Only 13mm so far, doesn't seem to be as bad as forecast yet.

jamie · Unread post by **jamie** » Mon 31/08/2015 18:11

David wrote:Only 13mm so far, doesn't seem to be as bad as forecast yet.

Its supposed to be tonight.

Bang on forecast here so far.

NZstorm · Unread post by **NZstorm** » Mon 31/08/2015 18:45

Manukau heads obs wrote:'non zero thunder risk'
love it, LOL

A round about way of saying low risk.

Latest midday modelling suggests NO thunder. The forecasting rule of thumb for thunder is convection tops must reach -20C and the cloud depth be atleast 3km. That requirement likely wont be met tomorrow morning but could happen Wednesday!

Chris Raine · Unread post by **Chris Raine** » Mon 31/08/2015 22:18

Winds have been steadily increasing on the West Coast this afternoon and this evening .The severe easterly gales are due to begin midnight . Emergency, services and Civil Defence on standby. getting generators into key areas if required

Manukau heads obs · Mon 31/08/2015 22:21

25mm today here...eased alot for now...more on the way I see

spwill · Unread post by **spwill** » Tue 01/09/2015 08:05

Some heavy showers to come through next hr or two before our weather brightens, a warm low of 14C overnight, 16mm at Greylynn since midnight

SnwAddct · Unread post by **SnwAddct** » Tue 01/09/2015 08:11

Torrential rain here in west Auckland..

Richard · Unread post by **Richard** » Tue 01/09/2015 08:25

Had a few spots so far, not looking like we will get much...again.

NZstorm · Unread post by **NZstorm** » Tue 01/09/2015 08:40

Tropical downpour in Grey Lynn.

Orion · Unread post by **Orion** » Tue 01/09/2015 09:18

In Auckland: "Emergency Services have now CLOSED Tamaki Drive from Ngapipi Road due to surface flooding and high tides..."
from
http://cdem.co/viewer.jsp?token=6sL9N6sc

NZstorm · Unread post by **NZstorm** » Tue 01/09/2015 09:50

I see Ricky had 47mm last 24hrs. I got 53mm.

jamie · Unread post by **jamie** » Tue 01/09/2015 10:01

I'm up to 37mm from this event with another downpour yet to come by the looks.

David · Unread post by **David** » Tue 01/09/2015 10:17

Only 34mm for the event here, nothing particularly heavy in Howick this morning.

David · Unread post by **David** » Tue 01/09/2015 10:21

Orion wrote:In Auckland: "Emergency Services have now CLOSED Tamaki Drive from Ngapipi Road due to surface flooding and high tides..."
from
http://cdem.co/viewer.jsp?token=6sL9N6sc

Yeah, the traffic was the worst I have ever seen this morning. Left 7.40am, turned around at 9.10am and came back home to work from home. I'm glad I did because my commute does include Tamaki Drive!

spwill · Unread post by **spwill** » Tue 01/09/2015 10:32

Got the downpour here before 9am

Manukau heads obs · Tue 01/09/2015 11:07

47mm here as well in total
There is now a lake at the bottom end of the valley here

Chris Raine · Unread post by **Chris Raine** » Tue 01/09/2015 13:05

Gusty easterly in Buller and Greymouth .The rain bearing front has now slipped into Central and south Westland

Tornado Tim · Unread post by **Tornado Tim** » Tue 01/09/2015 13:27

Quite a bit of heavy rain in Raglan,
SH23 as a result is closed due to flooding across the divy. Not good. Hopefully it will open later on today.....

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