General April Weather

NZ Thunderstorm Soc · Wed 05/04/2017 18:41

A bit of rain here today. Light variant winds for much of the day.
Waiting for the storm to arrive

Tornado Tim · Unread post by **Tornado Tim** » Wed 05/04/2017 21:59

Blimey mid late next week the mid to lower South Island could get some insane winds if GFS eventuates, a long shot at this stage but very interesting for sure.

David · Unread post by **David** » Thu 06/04/2017 20:03

Just when you think surely this pattern of regular deluges can't keep going on... modelling is showing the possibility of some more heavy rainfall next week. Will be interesting to see what happens - still a lot of variability between model runs

NZ Thunderstorm Soc · Thu 06/04/2017 21:13

Total of 36.7mm for today.

jamie · Unread post by **jamie** » Thu 06/04/2017 21:33

David wrote:Just when you think surely this pattern of regular deluges can't keep going on... modelling is showing the possibility of some more heavy rainfall next week. Will be interesting to see what happens - still a lot of variability between model runs

Crazy huh? I've been watching it and yea quite variable from run to run but more often than not the gfs runs have been for lots of rain than just a small/normal amount.

This pattern reminds me so much of Feb 2004 pattern. Low after low from the NW delivering lots of rain.

snowykiwi · Unread post by **snowykiwi** » Thu 06/04/2017 22:45

Tornado Tim wrote:Blimey mid late next week the mid to lower South Island could get some insane winds if GFS eventuates, a long shot at this stage but very interesting for sure.

How insane would these wind speeds be? We certainly don't need anymore rain next week. Certainly over the surface flooding we had down this way today.

NZstorm · Unread post by **NZstorm** » Fri 07/04/2017 07:18

European has a TC near New Caledonia next week. Tuesdays chart.
A trough in the Tasman which may become more polar for Easter in extended outlook.

jamie · Unread post by **jamie** » Fri 07/04/2017 09:56

NZstorm wrote:European has a TC near New Caledonia next week. Tuesdays chart.
A trough in the Tasman which may become more polar for Easter in extended outlook.

Check out the models! GFS and the ACCESS model both going for 100+ mm over the NI next week

GFS shows a another tasman low approaching but then getting a massive moisture injection from a TC moving down from Fiji way, colliding over the NI.

harleyb · Unread post by **harleyb** » Fri 07/04/2017 09:59

Just saw that too. This projection is from the MetVUW site. Early days yet but this really would not be good for much of the North Island if it eventuates, especially after what happened this week.

cbm · Unread post by **cbm** » Fri 07/04/2017 13:18

Sea temperature chart. This is absolute sea temperature, not anomalies. Looks like a tongue of unusually warm water has swept down past Tasmania and also a much smaller one past Hawke Bay. May be having an effect on weather systems

sea_temp_7-4-17.jpg

Tornado Tim · Unread post by **Tornado Tim** » Fri 07/04/2017 14:01

cbm wrote:Sea temperature chart. This is absolute sea temperature, not anomalies. Looks like a tongue of unusually warm water has swept down past Tasmania and also a much smaller one past Hawke Bay. May be having an effect on weather systems

Hey cbm, if you got that off SwellMap/WeatherMap, the data is derived from Model data which MetOcean runs.
Its what the model thinks the absolute SST is.

The real SST as observed by Satellite is attached, you'll notice its somewhat different but broader patterns are the same.

cbm · Unread post by **cbm** » Fri 07/04/2017 14:23

Tornado Tim wrote:
cbm wrote:Sea temperature chart. This is absolute sea temperature, not anomalies. Looks like a tongue of unusually warm water has swept down past Tasmania and also a much smaller one past Hawke Bay. May be having an effect on weather systems
Hey cbm, if you got that off SwellMap/WeatherMap, the data is derived from Model data which MetOcean runs.
Its what the model thinks the absolute SST is.

The real SST as observed by Satellite is attached, you'll notice its somewhat different but broader patterns are the same.

Cool, thanks. Yes, was from SwellMap. Best free source of such data I know of. I've since read that the East Australian current does sometimes bring warm water down past the East of Tasmania so not unprecedented. However do find it surprising how warm the water is now, given all the discussions that were had about how cold it was, during “Summer proper”.

TonyT · Unread post by **TonyT** » Fri 07/04/2017 16:21

cbm wrote: However do find it surprising how warm the water is now, given all the discussions that were had about how cold it was, during “Summer proper”.

The storms we are having now and in the next week will cool the surface off again later in the month.

NZstorm · Unread post by **NZstorm** » Sat 08/04/2017 07:42

Jet stream and subtropical moisture affecting NZ next week. The combo always ends up in a deluge somewhere.

Bradley · Unread post by **Bradley** » Sat 08/04/2017 14:53

Does anyone know what model the Metservice uses for its rain forecasts because their current severe weather warning map for heavy rain for the north and South Island next week looks almost identical to GFS and its rainfall forecast map?

Razor · Unread post by **Razor** » Sat 08/04/2017 15:36

For future reference...

Bradley · Unread post by **Bradley** » Sat 08/04/2017 16:20

Latest run of GFS looking grim with winds gusting over 120kmh over a large portion of the north and South Island and minimum pressure of around 987hpa on Thursday/Friday next week, this could be catastrophic with both rainfall and wind gusts...

jamie · Unread post by **jamie** » Sat 08/04/2017 17:46

Bradley wrote:Latest run of GFS looking grim with winds gusting over 120kmh over a large portion of the north and South Island and minimum pressure of around 987hpa on Thursday/Friday next week, this could be catastrophic with both rainfall and wind gusts...

The good thing is as with tropical cyclones, they do their own thing and can be hard to predict.

The models veered away from this scenario yesterday but have jumped back to it this afternoon. That will no doubt keep happening right up to the days before the event.

NZ Thunderstorm Soc · Sun 09/04/2017 18:47

+ Nice fine day here. Able to mow the lawns. Some mushrooms around

why didn't we get this rain in January, when we were trying to sell this property????

Anyway, interesting to see which way Cook will go later on this week?

Orion · Unread post by **Orion** » Sun 09/04/2017 19:00

Beautiful day here.
Went for a walk around 6:20pm, observed silvery moon (around 96% full) above the eastern horizon and bright-pink sunset clouds in the west, very pretty

NZstorm · Unread post by **NZstorm** » Sun 09/04/2017 19:16

Unfortunately a lot of high cloud over Auckland today. Max 21C.

Long range models suggest some colder unstable air over the NI for easter. Something to watch.

David · Unread post by **David** » Tue 11/04/2017 09:12

A large pine has collapsed recently in the local reserve following the series of heavy rain events over the last month or so. Was quite a surprise to see that given it hasn't been windy recently.

Orion · Unread post by **Orion** » Tue 11/04/2017 12:11

Puzzling, David - I wonder if it's been undermined somehow by storm-water runoff? or had its shallow rooting-system cut?
Must've come down with a whoomph!

David · Unread post by **David** » Tue 11/04/2017 13:09

Orion wrote:Puzzling, David - I wonder if it's been undermined somehow by storm-water runoff? or had its shallow rooting-system cut?
Must've come down with a whoomph!

I noticed it's been on a lean for quite a while. It was standing at the top of a steep bank, and I suspect that with each deluge flowing water gradually undermined part of the root system until it just couldn't support it's own weight anymore.

cbm · Unread post by **cbm** » Sat 15/04/2017 11:12

Something went wrong with the Hamilton AWS rain gauge on the 12th, nothing was recorded when there was widespread 50mm+ that day.

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