Sudden Stratospheric Warming Event (SH) 2019

[Razor]

I'm curious about the "2 only recorded ever before" media byline. Just how long have we been recordingor observing such a beast? I'm picking not very long?

[Chris Raine]

I have climat records for 2002 and 2012, I will go and look them up

[Cyclone Tracy]

I'm about the "2 only recorded ever before" media byline. Just how long have we been recordingor observing such a beast? I'm picking not very long?

Correct, not long at all relating to the stratosphere over Antarctica. Since 1979.

[Chris W]

I just hope the media don’t liken it to the NH ones. The “beast from the east” up there comes from a very cold and nearby continent in the event of a Scandinavian high linking to northern Russia, down here we don’t have that.

That said, it’s going to be interesting to see what comes of it, without hyping it too much.

[Bradley]

I just hope the media don’t liken it to the NH ones. The “beast from the east” up there comes from a very cold and nearby continent in the event of a Scandinavian high linking to northern Russia, down here we don’t have that.

That said, it’s going to be interesting to see what comes of it, without hyping it too much.

Nothing much to come of it in the next 2 weeks if both GFS and EC’s forecasts are to be believed

[snowchaser01]

I just hope the media don’t liken it to the NH ones. The “beast from the east” up there comes from a very cold and nearby continent in the event of a Scandinavian high linking to northern Russia, down here we don’t have that.

That said, it’s going to be interesting to see what comes of it, without hyping it too much.

Nothing much to come of it in the next 2 weeks if both GFS and EC’s forecasts are to be believed

We all know models struggle with such events so i wouldn't read too much into them. Will take a few weeks to kick into gear anyway.

[Richard]

Can anyone explain what happens to trigger off these warming events.

[Cyclone Tracy]

Can anyone explain what happens to trigger off these warming events.

Planetary waves (mostly Eddy heat ) propagate from the equatorial region towards poles. They weaken the stratospheric polar vortex over several episodes, over several months. Eventually the polar vortex is weakened to the point where it shifts equatorward or totally splits.

In my humble opinion, the earth is rebalancing the hot and cold through a process known as energy equilibrium. This one is on a grand scale

[Cyclone Tracy]

GFS continues to show a negative SAM (AAO) index going off the scales in the stratosphere within the next 10 days. IMO, short to medium term weather modelling will only become spooked if or when this propagates lower to around the jet stream (200 to 300hPa).

[midgrove]

I just hope the media don’t liken it to the NH ones. The “beast from the east” up there comes from a very cold and nearby continent in the event of a Scandinavian high linking to northern Russia, down here we don’t have that.

That said, it’s going to be interesting to see what comes of it, without hyping it too much.

Nothing much to come of it in the next 2 weeks if both GFS and EC’s forecasts are to be believed

It has already started - I think the media just googled SSW and extrapolated what happened in the Northern Hemisphere to New Zealand. I have seen several headlines referring to "the Beast from the East" or "icy blast from the east". Unfortunately they quote parts of the NIWA press release as if NIWA had coined those click-bait headlines. Also that SSW event caused a weakening then reversal of the stratospheric jet stream, which in turn weakened the 250-300Hpa polar jet-stream. The reverse seems to be happening here with 10Hpa westerlies in excess of 200 knots in the GFS model.

[Cyclone Tracy]

EC 00Z continues to peak the SSW this Friday into Saturday @ 10 hPa with a secondary temperature spike 5 days later on 4 September at which time a twin daughter vortex circulation develops in the lower stratosphere @ 100 hPa over the Antarctic continent.

[Cyclone Tracy]

GFS's 2508 00Z 3D structure view of the current stratospheric polar vortex and the projected 3D structure view 10 Sept. Sustained planetary wave attacks turns this polar beast into an asymmetric twisted shadow of it's former self. GFS has the SAM (AAO) index dropping to negative 6 near 10 hPa between 7 to 10 September.

[SirSlingy]

Damn I love your updates CT... just wish I could understand half of them!! Any laymans words on potential NZ impacts of the SSW event based on its progression so far?

[Cyclone Tracy]

Damn I love your updates CT... just wish I could understand half of them!! Any laymans words on potential NZ impacts of the SSW event based on its progression so far?

Sorry SirSlingy but I truly don't know what will happen and what the impact will be on NZ This has differences to the 2002 event, so I'm hunting the synoptic beast day by day, looking for signals on the models. That latest GFS 10th September structure image hints that the polar jetstream will be unleashed towards mid latitudes maybe around the equinox, in one of the most chaotic weather pattern switches ever witnessed in the southern hemisphere for the modern recorded era.....but this is all in world of computing non reality.

From this Friday, we will start to know if models have got the first phase right. The daily observations will start painting the picture of reality. Back to the popcorn

[SirSlingy]

Thanks CT... will go grab a bag or two myself, sit back and enjoy the show!

[TonyT]

.....but this is all in world of computing non reality.

Very important words in my opinion - we are using models to give us projections of this event, yet the models
a) haven't dealt with an event like this before; and
b) might not be designed (i.e. capable of) dealing with an event like this; and
c) might not have the physics needed to process what is happening; and
d) are likely to get tripped up by their own error limiting code if the internal physics generate data which the model itself is programmed not to believe.

Really important to go back to basics on this and not get too hung up on computer generated ideas. First rule of thermodynamics, conservation of energy, i.e. energy is not created or destroyed. Therefore, mess with the energy balance of the system high up over the Antarctic, then there has to be a consequence on the energy balance elsewhere. Every action has an equal and opposite re-action (in weather, we should "more or less" to that last statement!).

[Bradley]

Damn I love your updates CT... just wish I could understand half of them!! Any laymans words on potential NZ impacts of the SSW event based on its progression so far?

Sorry SirSlingy but I truly don't know what will happen and what the impact will be on NZ This has differences to the 2002 event, so I'm hunting the synoptic beast day by day, looking for signals on the models. That latest GFS 10th September structure image hints that the polar jetstream will be unleashed towards mid latitudes maybe around the equinox, in one of the most chaotic weather pattern switches ever witnessed in the southern hemisphere for the modern recorded era.....but this is all in world of computing non reality.

From this Friday, we will start to know if models have got the first phase right. The daily observations will start painting the picture of reality. Back to the popcorn

I’d just be happy with another 19th September 2005 event for Christchurch! Hell I’m not greedy, even 5cm of the white stuff on the ground would do!

[TonyT]

Sorry SirSlingy but I truly don't know what will happen and what the impact will be on NZ This has differences to the 2002 event, so I'm hunting the synoptic beast day by day, looking for signals on the models. That latest GFS 10th September structure image hints that the polar jetstream will be unleashed towards mid latitudes maybe around the equinox, in one of the most chaotic weather pattern switches ever witnessed in the southern hemisphere for the modern recorded era.....but this is all in world of computing non reality.

From this Friday, we will start to know if models have got the first phase right. The daily observations will start painting the picture of reality. Back to the popcorn

I’d just be happy with another 19th September 2005 event for Christchurch! Hell I’m not greedy, even 5cm of the white stuff on the ground would do!

Dont assume it will bring snow. Remember in October 2002 following the last big SSW we had record cold and record sunshine.

[Cyclone Tracy]

24 hours left on the countdown clock

Current notable observations.

A decimating onslaught of ozone harming molecules has mixed from the mid latitudes to the polar region around the stratosphere. This has broken a daily August ozone minimum records 4 days ago. This air chemistry change is a signal that polar vortex is under stress to allow the mixing to occur from below and above. This is a known precursor to a SSW event.

Scientists TAGUCHI HARTMANN in 2005 (TH05) linked the Pacific (El Nino) to the northern hemisphere’s Sudden stratospheric warming events using a hybrid NCAR climate model. As of today, there is intriguing correlation developing between the Pacific and the Stratosphere relating to energy transfer. Initial observations suggests that the pacific might be attempting to adjust the global climate knob to ‘cool mode’. There will be many climate science journals written about this event in the coming years I’m sure and a trending La Nina might be part of the discussion this time

[TonyT]

24 hours left on the countdown clock

Current notable observations.

A decimating onslaught of ozone harming molecules has mixed from the mid latitudes to the polar region around the stratosphere. This has broken a daily August ozone minimum records 4 days ago. This air chemistry change is a signal that polar vortex is under stress to allow the mixing to occur from below and above. This is a known precursor to a SSW event.

Scientists TAGUCHI HARTMANN in 2005 (TH05) linked the Pacific (El Nino) to the northern hemisphere’s Sudden stratospheric warming events using a hybrid NCAR climate model. As of today, there is intriguing correlation developing between the Pacific and the Stratosphere relating to energy transfer. Initial observations suggests that the pacific might be attempting to adjust the global climate knob to ‘cool mode’. There will be many climate science journals written about this event in the coming years I’m sure and a trending La Nina might be part of the discussion this time

There has been a fair bit written lately about how the SH oceans are for most part cooler than the long term normal while the NH is the reverse (i.e. warmer). This global "imbalance" has been seen before but currently its heading towards a more extreme version than we have seen at other times. Its all inter-related, if only we knew how!

[Bradley]

24 hours left on the countdown clock

Current notable observations.

A decimating onslaught of ozone harming molecules has mixed from the mid latitudes to the polar region around the stratosphere. This has broken a daily August ozone minimum records 4 days ago. This air chemistry change is a signal that polar vortex is under stress to allow the mixing to occur from below and above. This is a known precursor to a SSW event.

Scientists TAGUCHI HARTMANN in 2005 (TH05) linked the Pacific (El Nino) to the northern hemisphere’s Sudden stratospheric warming events using a hybrid NCAR climate model. As of today, there is intriguing correlation developing between the Pacific and the Stratosphere relating to energy transfer. Initial observations suggests that the pacific might be attempting to adjust the global climate knob to ‘cool mode’. There will be many climate science journals written about this event in the coming years I’m sure and a trending La Nina might be part of the discussion this time

There has been a fair bit written lately about how the SH oceans are for most part cooler than the long term normal while the NH is the reverse (i.e. warmer). This global "imbalance" has been seen before but currently its heading towards a more extreme version than we have seen at other times. Its all inter-related, if only we knew how!

Fascinating observations on the coming SSW event as always gents, I know everyone in the forums appreciates your valuable and expert input As a side note NIWA has just released it's September forecast pressure anamoly - no words are needed really looking at the below forecast map, seems to be in line exactly as everyone has been forecasting

file-19.jpeg

[Richard]

........ a trending La Nina might be part of the discussion this time

One wonders if such a significant SSW as this will lead to an equally significant La Nino period afterwards.

[Cyclone Tracy]

There has been a fair bit written lately about how the SH oceans are for most part cooler than the long term normal while the NH is the reverse (i.e. warmer). This global "imbalance" has been seen before but currently its heading towards a more extreme version than we have seen at other times. Its all inter-related, if only we knew how!

Yes, it's the great unknown. On the July outputs, 2 out of 27 global climate models picked the Nino. 3.4 negative trend in August. Within the last 60 days 24 out of 27 models are out by 0.5 to 1.5c within the current trend. Now the incoming SSW.... I might have to check out what is going on in the mesosphere, there might be a skeleton in that closet as well

[Cyclone Tracy]

........ a trending La Nina might be part of the discussion this time

One wonders if such a significant SSW as this will lead to an equally significant La Nino period afterwards.

Good question, I certainly don't have an answer. Only time will tell.

The moderate 2010 SSW southern hemisphere event occurred with a moderate to strong incoming La Nina.

[TonyT]

........ a trending La Nina might be part of the discussion this time

One wonders if such a significant SSW as this will lead to an equally significant La Nino period afterwards.

I'm pretty sure there is no known reason to believe that one would "cause" the other. However, I did speculate in my seasonal advice to clients 2 weeks ago whether the SSW event will cause colder than usual SSTs to develop in the Southern Ocean (not due to cold air arriving from the pole specifically, more due to increased storminess and hence greater wind induced mixing of surface and deeper layers). If so, then the natural counter-consequence of that could be a warmer than usual Tasman Sea developing. If this happens then we have the classic La Nina SST signature set up around New Zealand, regardless of whether an atmospheric/ocean coupled La Nina event does develop in the Pacific.