Stratospheric Warming event on the way?

[donsutherland1]

Very interesting subject here. Enjoying all the information! Did a SSW turn the switch on the late starting winter of 1998-1999?

There were two SSW events that winter. The December 15, 1998 SSW event had no appreciable impact on blocking. The February 26, 1999 SSW event led to a period of strong blocking in March.

[usedtobe]

For those who think the warming has made much of a difference. Here's a chart from the japanese showing the 30 mb temps compared to normal. They are way below normal. The slight spike with the warming quickly was beat down. The winds are strongly westerly. I'm no expert but as HM has noted. SSW events aren't that common and with the temps so cold it's a stretch to think one is on the immediate horizon (at least that's my view).

Does that completely say there can be no blocking, no. Most likely for us any blocking would start in AK or siberia.

[The_Global_Warmer]

Where do we get these temps from ? sats? Weather balloons? Real time OBS? Model extrap?

[donsutherland1]

For those who think the warming has made much of a difference. Here's a chart from the japanese showing the 30 mb temps compared to normal. They are way below normal. The slight spike with the warming quickly was beat down. The winds are strongly westerly. I'm no expert but as HM has noted. SSW events aren't that common and with the temps so cold it's a stretch to think one is on the immediate horizon (at least that's my view).

Does that completely say there can be no blocking, no. Most likely for us any blocking would start in AK or siberia.

I agree with you, Wes.

So far, IMO no SSW is imminent. Each modest attempt at warming has been reversed to date. Many winters don't experience such events, so expectations for such an event probably should be restrained unless there is strong evidence that such an event is likely.

[dtk]

Where do we get these temps from ? sats? Weather balloons? Real time OBS? Model extrap?

Most of the products that are shown are from gridded analyses (global model initial conditions, though likely from the late-cutoff runs). So it's a combination of a short term (06-h) forecast and corrections from observations (rawindsonde/balloons and quite a bit of satellite data [MW/IR radiances] including GPS radio occultation data).

[usedtobe]

Most of the products that are shown are from gridded analyses (global model initial conditions, though likely from the late-cutoff runs). So it's a combination of a short term (06-h) forecast and corrections from observations (rawindsonde/balloons and quite a bit of satellite data [MW/IR radiances] including GPS radio occultation data).

Daryl thanks, I was just getting the Japanese explanation when you posted and it pretty much says the same thing. The product I posted was from there gridded analyses.

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/html_e/readme.html

[Weathergun]

For those who think the warming has made much of a difference. Here's a chart from the japanese showing the 30 mb temps compared to normal. They are way below normal. The slight spike with the warming quickly was beat down. The winds are strongly westerly. I'm no expert but as HM has noted. SSW events aren't that common and with the temps so cold it's a stretch to think one is on the immediate horizon (at least that's my view).

Does that completely say there can be no blocking, no. Most likely for us any blocking would start in AK or siberia.

This chart looks out of date, for this week. These charts show more recent spike in temps occurring 10hpa and 30hpa. The 10hpa temps are getting within majority spread:

You go this site, to find these maps, and you will see recent spike occurring on in their higher latitudes right now. The average temp between 60-90N, has shown a recent spike as well:

http://acd-ext.gsfc....t/ann_data.html

However, I don't also believe this is a major SSW yet and I am concerned about the Euro forecast changes with the EP flux, that this warming won't fully propagate into the troposphere. Not in time, for a major change in late Dec or early Jan.

[Rainshadow]

Excellent information and thread!

[cooling climate]

For those who think the warming has made much of a difference. Here's a chart from the japanese showing the 30 mb temps compared to normal. They are way below normal. The slight spike with the warming quickly was beat down. The winds are strongly westerly. I'm no expert but as HM has noted. SSW events aren't that common and with the temps so cold it's a stretch to think one is on the immediate horizon (at least that's my view).

Does that completely say there can be no blocking, no. Most likely for us any blocking would start in AK or siberia.

The warming that has been talked about in this thread is at the 1 and 5 hpa level at t240 so

it will be a while yet before we see any response at the 30 hpa level. At least this is what I

think Chionomaniac has been refering to.

[usedtobe]

The warming that has been talked about in this thread is at the 1 and 5 hpa level at t240 so

it will be a while yet before we see any response at the 30 hpa level. At least this is what I

think Chionomaniac has been refering to.

As Don and I mentioned, even if it makes it to 30 mb and the winds at that level reverse and we're way away from taht now, there is no guarantee even with a ssw event that the AO and nao will go negative. Much depends on the EP flux. SSW events are not that common, minor warming events like the past one are. As to the chart that showed the spike downward in temps stopping, the temps still were way below normal.

[mitchnick]

a "ray" of hope for the demise of the vortex?

http://www.solen.info/solar/index.html

[Geos]

a "ray" of hope for the demise of the vortex?

http://www.solen.info/solar/index.html

With the decrease in solar activity? Incoming solar activity does affect the atmosphere. Last winter there wasn't much sunspot/storm activity to speak of.

[Isotherm]

a "ray" of hope for the demise of the vortex?

http://www.solen.info/solar/index.html

More than a ray in my opinion; it's the primary reason why I think we'll turn around in terms of AO/NAO modality by early to mid January.

[tacoman25]

More than a ray in my opinion; it's the primary reason why I think we'll turn around in terms of AO/NAO modality by early to mid January.

But I thought you believed the AP geomagnetic index was the primary solar driver for blocking? That has been very low for quite awhile.

[BethesdaWX]

But I thought you believed the AP geomagnetic index was the primary solar driver for blocking? That has been very low for quite awhile.

The AP index is more CME related I assume, the background solarcharged winds had been higher at near 375km per sec.

[Isotherm]

But I thought you believed the AP geomagnetic index was the primary solar driver for blocking? That has been very low for quite awhile.

Ap values were surging over 10 (up to 60 one day) quite a few times before November, which in conjunction with high solar flux likely aided in the +AO/NAO. Since late Nov, the Ap has been consistently back below 5 and the solar flux down from 180 to 120 now.

[mitchnick]

Ap values were surging over 10 (up to 60 one day) quite a few times before November, which in conjunction with high solar flux likely aided in the +AO/NAO. Since late Nov, the Ap has been consistently back below 5 and the solar flux down from 180 to 120 now.

have you looked at the 12/16 5mb and 10mb maps for days 8-10 at the Berlin site?

quite a warming predicted that begins day 8 and is going full blast by day 10

hopefully, it will work its way down

http://www.geo.fu-be...tics/index.html

[Amped]

Satellite data is very good in the stratosphere. This is because parameters changes much more slowly with elevation.

[okie333]

12Z GFS:

[chionomaniac]

I think that it is a patient waiting game stratospheric wise presently. We are seeing an extremely cold stratosphere slowly giving way to remote tropsospheric wave breaking, a slow increase in ozone levels and a reduction in the residual westerly QBO at lower tropical stratospheric levels.

All this will slowly turn around unfavourable stratospheric conditions to something more favourable with or without a SSW by the second half of winter. No quick switch around is likely unless we see a split SSW.

Of interest is that the last few long range GFS runs have suggested a warming over the North Pole at T+384 at 1hPa with the cold air totally displaced. If this was to occur then the vortex at this level would be seriously compromised.

[The_Global_Warmer]

Is there any evidence of the sun triggering these events ?

[BethesdaWX]

Is there any evidence of the sun triggering these events ?

There is inconclusive evidence that diminished activity states may lead to a more favorable profile for sudden warmings.

[am19psu]

There is inconclusive evidence that diminished activity states may lead to a more favorable profile for sudden warmings.

...during easterly QBOs

[BethesdaWX]

...during easterly QBOs

You're referencing the 11 year sunspot cycle, right? I was attempting to reference the background solarcharged wind speed and density specifically, which did not drop to extremely low values until sometime in 2009 and remained very weak until spring 2011 I believe, correct me if I have the wrong date.

I figure thats why there was no extreme blocking until it crashed in 2009, despite the overall minimum in 2008, as well as the -NAO in 2010/11 occuring during the period of weaker charged winds.

[am19psu]

You're referencing the 11 year sunspot cycle, right? I was attempting to reference the background solarcharged wind speed and density specifically, which did not drop to extremely low values until sometime in 2009 and remained very weak until spring 2011 I believe, correct me if I have the wrong date.

I figure thats why there was no extreme blocking until it crashed in 2009, despite the overall minimum in 2008, as well as the -NAO in 2010/11 occuring during the period of weaker charged winds.

I was actually referencing the papers in academic journals that show SSWs are more favorable with a weak sun during easterly QBOs and with an active sun during westerly QBOs.

[usedtobe]

I was actually referencing the papers in academic journals that show SSWs are more favorable with a weak sun during easterly QBOs and with an active sun during westerly QBOs.

Here's one of the articles that you are referring to. I think I've posted this before for Bwx but maybe my memory is tricking me.

http://journals.ametsoc.org/doi/pdf/10.1175/JAS-3297.1

[BethesdaWX]

I was actually referencing the papers in academic journals that show SSWs are more favorable with a weak sun during easterly QBOs and with an active sun during westerly QBOs.

But what aspect of the Sun are you alluding to? The 11 year TSI cycle I presume? Bunching TSI together with the solarcharged winds might scew the effect the they had in 2010/11 despite the +QBO. Even though there was no big difference in TSI from previous minimums the charged particle winds fell to all time lows in 2009 into early 2011 which is when we saw all of our extreme blocking.

[okie333]

38.0

41.0?!?!

Fantasy range, but 7.2 at 10mb

[Big O]

38.0

41.0?!?!

Fantasy range, but 7.2 at 10mb

What does this mean for the CONUS (i.e., please translate)?

[okie333]

In the long-range, one is seeing a shrinking of the area of warm anomalies and deepening cold ones. That could be an indication of a lack of blocking in the long-range. If the long-range forecast plays out, the polar vortex would strengthen anew and a strong AO+ regime would reassert itself. That would increase prospects for warmth in the East, especially if a PNA- setup is in place.

That last map was from 10mb not 1mb. Big difference. I only posted it to show that the warming actually downwells as opposed to staying up at 1mb.