General May Weather

[Cyclone Tracy]

Stratospheric warming from mid May is on the move. SAM indicator is dropping like a rock. Antarctic surface temps are on the rise. A strong incoming Long wave trough for next week. A change of weather pattern is arriving soon

[Bradley]

Stratospheric warming from mid May is on the move. SAM indicator is dropping like a rock. Antarctic surface temps are on the rise. A strong incoming Long wave trough for next week. A change of weather pattern is arriving soon

Oh boy I hope so, May running 3C above average for maximums in Christchurch, waiting for these SW changes that have been talked about recently, even the minimums in Christchurch have been warmer then the longterm average which goes against late May cold/frosty predictions back in April, something must have changed in the atmosphere for this to be the case?

[Cyclone Tracy]

Stratospheric warming from mid May is on the move. SAM indicator is dropping like a rock. Antarctic surface temps are on the rise. A strong incoming Long wave trough for next week. A change of weather pattern is arriving soon

Oh boy I hope so, May running 3C above average for maximums in Christchurch, waiting for these SW changes that have been talked about recently, even the minimums in Christchurch have been warmer then the longterm average which goes against late May cold/frosty predictions back in April, something must have changed in the atmosphere for this to be the case?

In my opinion, its due to the Hadley cell being further south than normal since November. This has meant long sustained periods of high pressure which has spiked the sea surface temperatures and shielded NZ from tropical moisture . A recipe for warmer and drier than normal for most areas. Why it has happened maybe for another topic

[Richard]

Where the NW wind has reached out to, Culverden clearly hasn't received the wind change yet. 18 deg here

bcc2fb64-449c-4e33-9d68-89691fb0dcda.png

[TonyT]

... waiting for these SW changes that have been talked about recently, even the minimums in Christchurch have been warmer then the longterm average which goes against late May cold/frosty predictions back in April, something must have changed in the atmosphere for this to be the case?

Or simply that the interpretation of a period of southwest airflow (which has arrived) as bringing SW changes and cold nights (which they often do) hasn't played out in this case. An example of predicting the pattern correctly but the resulting weather has not been the expected result. Honestly, if forecasting was easy then everyone would be doing it!

[Chris W]

... waiting for these SW changes that have been talked about recently, even the minimums in Christchurch have been warmer then the longterm average which goes against late May cold/frosty predictions back in April, something must have changed in the atmosphere for this to be the case?

Or simply that the interpretation of a period of southwest airflow (which has arrived) as bringing SW changes and cold nights (which they often do) hasn't played out in this case. An example of predicting the pattern correctly but the resulting weather has not been the expected result. Honestly, if forecasting was easy then everyone would be doing it!

We've certainly had cold nights in town including after SW changes, but also northerlies and the daytimes have been very warm. 7 days out from a potentially significant pattern change going by several days off GFS runs and a look at EC yesterday.

[NZ Thunderstorm Soc]

Where the NW wind has reached out to, Culverden clearly hasn't received the wind change yet. 18 deg here
bcc2fb64-449c-4e33-9d68-89691fb0dcda.png

You can get that in Geraldine. might be warm at Levels and Ashburton but still in the single figures here.
Cold day here today with NW sky and calm.
Here's an example of looking towards the 4 Peaks range in cold NW conditions

[tornado]

misty in auckland now

[snowchaser01]

Looks like a significant change in weather pattern in about 7-10 days time...
EC and GFS in agreement of a cold change (potentially significant) on or around the 31st.

[Richard]

Where the NW wind has reached out to, Culverden clearly hasn't received the wind change yet. 18 deg here
bcc2fb64-449c-4e33-9d68-89691fb0dcda.png

You can get that in Geraldine. might be warm at Levels and Ashburton but still in the single figures here.
Cold day here today with NW sky and calm.
Here's an example of looking towards the 4 Peaks range in cold NW conditions

Hope you picked up that piece of plastic John

[Cyclone Tracy]

NASA's GEOS displaying a well defined stratospheric polar vortex that has coupled into the troposphere with a weakened jagged edge of the lower level polar jet pulsing into NZ region for the start of June.

[Thunder081]

This time last year there was like 4 days of lightning in the lower western north island. Some years are good but this year is still so boring.

[NZ Thunderstorm Soc]

NASA's GEOS displaying a well defined stratospheric polar vortex that has coupled into the troposphere with a weakened jagged edge of the lower level polar jet pulsing into NZ region for the start of June.

Looks like a pint glass of beer.
What sort of brew would occur in a 'glass' of this size?

[TonyT]

Looks like a pint glass of beer.
What sort of brew would occur in a 'glass' of this size?

Whatever it is, its got a lot of ice in it, and its leaking out of the bottom of the glass.

[NZ Thunderstorm Soc]

Hope you picked up that piece of plastic John

YES. ....and there was lots of other rubbish around in the area probably thrown out by people who don't care about the envoirement.

[Chris W]

Extremely dense fog on State Highway 1 driving home from Amberley tonight, around Saltwater Creek visibility was very low indeed as you might expect. Started at Amberley and lifted at Pegasus as usual, just much thicker than normal with an air temperature of 9C.

[tornado]

potential thunderstorms for auckland next week as a large low moves in

[spwill]

potential thunderstorms for auckland next week as a large low moves in

Will keep an eye on Tuesday at this stage, a significant looking trough.

[tornado]

yeah might have a potiental to produce a small tornado or two.

[cbm]

My station climbed from 4.4 at 6am to 7.8C by 7am with the arrival of a slight SE. Which made for a nice fine mild morning for this time of year.

Sent from my SM-N950F using Tapatalk

[Cyclone Tracy]

Currently I'm on 175mm YTD. This time last year I was 655mm. My local average by the end of May is 458mm.

My records began in 2001 and I've never recorded under 200mm by the end of May.

[David]

Currently I'm on 175mm YTD. This time last year I was 655mm. My local average by the end of May is 458mm.

My records began in 2001 and I've never recorded under 200mm by the end of May.

Wow, that is really low for almost 5 months worth! My station is up to 265mm YTD. Not quite the driest year - 2010 and 2014 were at 242mm and 246mm at the same point in the year.

[TonyT]

Currently I'm on 175mm YTD. This time last year I was 655mm. My local average by the end of May is 458mm.

My records began in 2001 and I've never recorded under 200mm by the end of May.

You might just get the 25mm you need.

[Cyclone Tracy]

Currently I'm on 175mm YTD. This time last year I was 655mm. My local average by the end of May is 458mm.

My records began in 2001 and I've never recorded under 200mm by the end of May.

Wow, that is really low for almost 5 months worth! My station is up to 265mm YTD. Not quite the driest year - 2010 and 2014 were at 242mm and 246mm at the same point in the year.

No synoptic scale north easterly system arrived during the warmer months, which has traditionally given my gauge a good working over. My lowest to the end of May is 211mm in 2014. Time is running out

[Chris W]

After the foggy conditions across NZ we are looking good for several days of norwesters from tomorrow - Metservice this morning issued a warning for Fiordland and a watch for at least 500mm in 5 days for the coast - then a strong southerly change around the 30th, then GFS is keen on things getting even colder particularly around Queen's Birthday weekend. Some way to go and no doubt many model output changes to come yet, but possibly an active start to winter.