General May Weather

[Orion]

I’m just a lurker who loves a bit of weather, but I’d also love to know more about the sudden stratospheric warming!

Welcome, Iloveweather

[Thunder081]

Yeah Mr Tracy does post some useful stuff especially when he was posting the models projected positions for ex tc gita

[talbotmj15]

Hopefully CT hasnt been put off posting after 1 stupid comment. There does seem alot of negativity lately on this thread. I would ask the moderators to deal with some of the targeted attacks. I hope CT does do more posts as his knowledge is next level and well above most in this forum and he puts it into form we all can understand.

[NZstorm]

Still hanging onto the mild weather here with a 6am temp 17C.

[treetop]

High pressure looks stationary over the Aust Bight for a while now so the end of the warm weather up north. Brace for frequent showers and gales ["squallageddon"]

[Richard]

And for us in Canterbury we can look forward to 'galeageddon' oh joy

[melja]

NW gale tho so reasonable mild.

Sent from my Lenovo K50a40 using Tapatalk

[Cyclone Tracy]

Thanks to all for your feedback.

Dew point still high and with multiple troughs around the upper NI today, might get a rumble.

I see there is some interest with the SSW, so here is my 2 bobs worth as I see it at the moment. I tell you that it has now normalised in the stratosphere and the full impacts of the SSW have now reached the surface of Antarctica. The polar continent is still around +4c above normal and certain areas have reached a 20c + anomaly. One spot is 28c degrees above normal.

The zonal wind changes from the stratosphere into the troposphere can cause fractures and displacements of the sub tropical and polar jet streams. The high pressure ridge that is becoming stationery over the Australian bight is directly related to the SSW. It no longer has the steering of the Jets, it’s becoming surrounded and is becoming stationary. This can allow polar cold waves to launch east of the ridge into the mid latitudes….and NZ could be in the firing line.

As I mentioned in mid April, I have never seen a set up like this before as the sea surface temperatures are well above what would exist in July. Hobart just found out what this means with a 170 year May rainfall record smashed last Thursday evening due to extreme moisture advection off a warm Tasman which was triggered from a polar upper low which spawned the surface low and rain bomb. EC and GFS predicted around 20mm to 50mm for greater Hobart on the 00z run as the rain commenced. 125mm + fell. The big models had no historic precedence to refer to and got moisture levels so wrong.

I’m still not 100% certain of what the impact is on NZ but I was sure that the models would become randomly extreme in the 2nd half of May with the synoptics to follow. Attached is the yesterday’s synoptics of the conveyor belt of polar lows and the temps of Antarctica, no projections, just real data

[Achten]

Thanks CT, really enjoy your posts.

[Razor]

Hopefully CT hasnt been put off posting after 1 stupid comment. There does seem alot of negativity lately on this thread. I would ask the moderators to deal with some of the targeted attacks. I hope CT does do more posts as his knowledge is next level and well above most in this forum and he puts it into form we all can understand.

Agree in part- I wouldn't say I've seen l lot of it, but when it does pop up lets not fight negativity with more negativity please (a general comment not an accusation).

On notice everyone please, go play on other forms of social if you want to have personal comments of such nature

[melja]

Raining and foggy in Chch ATM.

Sent from my Lenovo K50a40 using Tapatalk

[spwill]

A few Cbs coming into the Auckland area now, has been up to 22C in places this morning, dp 16C.

[David]

Will be interesting to see what unfolds next week. Just seen the latest GFS has a very deep low passing just south of Invercargill. Not often you see them that deep that close to NZ.

[Cyclone Tracy]

Will be interesting to see what unfolds next week. Just seen the latest GFS has a very deep low passing just south of Invercargill. Not often you see them that deep that close to NZ.

The models are starting to get quite volatile. Even EC lost it's cool 2 days ago before calming down . CMC this morning on the 12Z run has produced the NI storm of the century mid to late next week. https://weather.us/model-charts/can/new ... 1200z.html

Obviously nothing can be taken too seriously yet but it shows how volatile levels around 500 hPa are becoming when a major polar injection gets into the mix.

[talbotmj15]

One can only imagine how much work is going on behind the scenes at the Met-service and Niwa offices. All the major models are really struggling to make sense of whats happening. There appears to be some massively deep Lows on each model run. This has been triggered for multiple days and nearly every run on every model appears different. Its a forecasters Nightmare.

I can see how Hobart got hammered when the moisture outputs were low on the models. The models just cant deal with it at all. With all the changes in the Atmospheric, Stratospheric layers and then throw in the SSTs abnormality. So much data is outside there normal benchmark parameters. I guess this is where the Qualified Professional Meteorologists earn there pay packets.

On a side note its airily quiet and quite cool today. Single figures for mid Canterbury and has been for a few days. Getting progressively colder each day. Very Dull with Misty rain for about the 5 day in a row. Thanks again CT for your great intel.

[TonyT]

Models are by design limited to what the programmers of them think they know. They are not artificially intelligent. Most of the time they work well because the atmosphere is working within well known (I was tempted to write "understood" but I will stick with "known") parameters and processes. When the atmosphere gets to the fringes of what the physics thinks ought to happen, weirdness is the result. There are a number of factors which are only going to make this worse in the next few years in my opinion (geomagnetic changes, changing upper atmospheric dynamics, deep solar minimum to name a few).

[BeaconHill]

Time-lapse from electrical storm over Taranaki last night (via Primo Wireless). Rather vigorous!
(Warning - has loud music!)



They also have a cool selection of webcams around the Taranaki region, including a number along the coast.
https://primowireless.co.nz/info/primo-webcams

[NZ Thunderstorm Soc]

And for us in Canterbury we can look forward to 'galeageddon' oh joy

.....also 'claggageddon' which we have had here in Geraldine for much of this week.

[Razor]

...geomagnetic changes...

I'm curious on this one...

[TonyT]

...geomagnetic changes...

I'm curious on this one...

Our north and south magnetic poles are moving at an accelerating rate, and our magnetic field strength is varying more than previously, and generally weakening. This may well be related to observed changes in the magnetosphere (which in turn affects the upper atmospheric dynamics). Its also probably to do with solar changes (weaker solar wind, more GCRs impacting the planet and potentially altering the underlying magnetic structure). LOD and other orbital parameters may be increasingly affected, and if so there could be linkages back to weather patterns (primarily via jet stream movements). Global AAM (atmospheric angular momentum, or approximately global wind) has weakened in the last 25 years. Its all rather speculative and very poorly understood at present, but I'm a suspicious old chap, and our period of observing the atmosphere is so short in comparison to the timescale of these broader planetary and cosmic influences, that I'm wary of suggesting we have all the drivers of weather patterns well understood at this point in time. The more you learn, the more you realise you dont know!

[NZstorm]

BeaconHill, the clip isn't working.

Heard some thunder around 12.30pm out on Auckland's west coast (Bethells) where I was working today.

[treetop]

cannot view your video beakonhill , anyone else have probs ?

[Richard]

cannot view your video beakonhill , anyone else have probs ?

yes

[Nev]

cannot view your video beakonhill , anyone else have probs ?

Fixed now.

[NZ Thunderstorm Soc]

Finally coming onto rain, reducing the 'Claggness' of the weather here.