sebastiaan1973

GEM same story as GFS. A anticyclone in the north west of continental Europe.

It is clear from the Plume of the De Bilt that there is indeed no cold available.

Yes, it does around day 10, later on the anticyclone moves to the west.

Windplume De Bilt this morning and evening. An significant increase memebers with easterly winds (control included). O= East. Controle = Control (blue line)

The direction of the WA is by EC the worse. (216h) EC, GFS and GEM.

Very interesting, I share iot here too, because it is important for understanding the models. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015JD023359 Simon Lee writes in a tweet about this article. If we have a reflective type of SSW (Judah Cohen states the same), this leads to a Pacific blocking and westerlies over the N-A Abstract Sudden stratospheric warming (SSW) events have received increased attention since their impacts on the troposphere became evident recently. Studies of SSW usually focus on polar stratospheric conditions; however, understanding the global impact of these events requires studying them from a wider perspective. Case studies are used to clarify the characteristics of the stratosphere-troposphere dynamical coupling, and the meridional extent of the phenomena associated with SSW. Results show that differences in the recovery phase can be used to classify SSW events into two types. The first is the absorbing type of SSW, which has a longer timescale as well as a larger meridional extent due to the persistent incoming planetary waves from the troposphere. The absorbing type of SSW is related to the annular mode on the surface through poleward and downward migration of the deceleration region of the polar night jet. The other is the reflecting type. This is characterized by a quick termination of the warming episode due to the reflection of planetary waves in the stratosphere, which leads to an amplification of tropospheric planetary waves inducing strong westerlies over the North Atlantic and blocking over the North Pacific sector. Differences in the tropospheric impact of the absorbing and reflecting SSWs are also confirmed with composite analysis of 22 major SSWs. Key Points New classification of sudden stratospheric warming during the recovery phase Absorbing type warming events induce Arctic Oscillation on the surface Reflecting-type warming events produce a Pacific blocking Edit. I place the tropospheric setting after Absorbing & Reflecting. Original post: https://community.netweather.tv/topic/99793-model-output-discussion-cold-spell-ending-what-next/?do=findComment&comment=5017833

There are some beauties in the GFS ENS.

Very interesting, I share it here too, because it is important for understanding the models. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015JD023359 Simon Lee writes in a tweet about this article. If we have a reflective type of SSW (Judah Cohen states the same), this leads to a Pacific blocking and westerlies over the North Atlantic Ocean Abstract Sudden stratospheric warming (SSW) events have received increased attention since their impacts on the troposphere became evident recently. Studies of SSW usually focus on polar stratospheric conditions; however, understanding the global impact of these events requires studying them from a wider perspective. Case studies are used to clarify the characteristics of the stratosphere-troposphere dynamical coupling, and the meridional extent of the phenomena associated with SSW. Results show that differences in the recovery phase can be used to classify SSW events into two types. The first is the absorbing type of SSW, which has a longer timescale as well as a larger meridional extent due to the persistent incoming planetary waves from the troposphere. The absorbing type of SSW is related to the annular mode on the surface through poleward and downward migration of the deceleration region of the polar night jet. The other is the reflecting type. This is characterized by a quick termination of the warming episode due to the reflection of planetary waves in the stratosphere, which leads to an amplification of tropospheric planetary waves inducing strong westerlies over the North Atlantic and blocking over the North Pacific sector. Differences in the tropospheric impact of the absorbing and reflecting SSWs are also confirmed with composite analysis of 22 major SSWs. Key Points New classification of sudden stratospheric warming during the recovery phase Absorbing type warming events induce Arctic Oscillation on the surface Reflecting-type warming events produce a Pacific blocking For the reflecting type (the SSWs in February 1979, December 1998, February 2007, and February 2008.), the deceleration of stratospheric zonal winds is confined mainly to the polar region. Warming is rapidly terminated by reflection of planetary waves, which induces downward propagation of the wave packets. Fluctuations, including intermittent warming periods, precede or follow the major warming. The tropospheric response of this type of SSW appears as an amplification of the tropospheric planetary wave in the recovery phase of the SSW. In particular, a deepening trough over the North Atlantic and an enhancing ridge in the North Pacific sector are evident. The latter enhancement provides a favorable condition for a blocking formation over the North Pacific. Edit. I place the tropospheric setting after Absorbing & Reflecting.

Intresting. This is the article Simon Lee writes about. If we have a reflective type of SSW (Judah Cohen states the same), this leads to a Pacific blocking and westerlies over the N-A Abstract Sudden stratospheric warming (SSW) events have received increased attention since their impacts on the troposphere became evident recently. Studies of SSW usually focus on polar stratospheric conditions; however, understanding the global impact of these events requires studying them from a wider perspective. Case studies are used to clarify the characteristics of the stratosphere-troposphere dynamical coupling, and the meridional extent of the phenomena associated with SSW. Results show that differences in the recovery phase can be used to classify SSW events into two types. The first is the absorbing type of SSW, which has a longer timescale as well as a larger meridional extent due to the persistent incoming planetary waves from the troposphere. The absorbing type of SSW is related to the annular mode on the surface through poleward and downward migration of the deceleration region of the polar night jet. The other is the reflecting type. This is characterized by a quick termination of the warming episode due to the reflection of planetary waves in the stratosphere, which leads to an amplification of tropospheric planetary waves inducing strong westerlies over the North Atlantic and blocking over the North Pacific sector. Differences in the tropospheric impact of the absorbing and reflecting SSWs are also confirmed with composite analysis of 22 major SSWs. Key Points New classification of sudden stratospheric warming during the recovery phase Absorbing type warming events induce Arctic Oscillation on the surface Reflecting-type warming events produce a Pacific blocking

How reliable is EC46 with MJO? Additional note. Amy Butler suggests the Greenland anticyclone was reinforced by the minor warming. But what makes the stratosphere’s current behavior unexpected and somewhat rare is that the polar vortex seems to be more disrupted at the lower levels, closer to the stratosphere-troposphere boundary. For more than a week, high pressure has been sitting in the troposphere over Greenland . It’s possible that the recent minor stratosphere warming reinforced this Greenland high pressure, which then drove a wedge into the stretched-out polar vortex in the lowest part of the stratosphere, splitting it into two lobes. The polar vortex is acting up | NOAA Climate.gov WWW.CLIMATE.GOV The latest forecast says a major disruption of the polar vortex is on its way, but the stratosphere has been acting up for a while. Our bloggers explain what it might mean...

This cold of 2018 was impressive. Still at the fourth of march I was able to skate. The 28th of February had a record cold tmax. Which is in our warming world quite remarkable.

You mean 2 weeks?

I would say I see some similarities at these three. GFS, EC & 27th of January 1956.

Who's quote is that?

I guess the support of a true Scandi high is quite low. Please see the windchart. NO/O/ZO = NE, E, SE are just a very little portion of the members.

The wind plume at De Bilt, gives the same grim picture. Z= south, NO= noordoost, ZO= zuidoost.

I understand your feeling, living close to Amsterdam.

It is hard to say things in a way everybody understands and makes the right conclusions. Thanks for sharing your thoughts. EC46 shows a return of a block at the northern part of the Atlantic Ocean.

The sea between Sweden and Finland, the northern part of the Gulf of Bothnia. is frozen. This is quite remarkable. Please look at the extent. This can be important if the wind will turn to the northeast later on. In the weatehrmodels we see a persistence of cold (er than average) weather in Scandinavia. Original post: https://community.netweather.tv/topic/99760-model-output-discussion-colder-but-how-cold-and-for-how-long/?do=findComment&comment=5004647

A part of the sea between Sweden and Finland, the northern part of the Gulf of Bothnia. is frozen. This is quite remarkable. Please look at the extent. This can be important if the wind will turn to the northeast later on. In the weatehrmodels we see a persistence of cold (er than average) weather in Scandinavia.

I'm not Lorenzo either, but I think you have to watch the work of Domeisen. In this chart you see the downwelling divided in 4 regimes. Right now we have blocking. This means there will be 2 significant downwellings after this one. This doesn't mean winter at the British Isles or at home in the Netherlands, but increased chance of negative AO. Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=5002381

https://wcd.copernicus.org/preprints/wcd-2019-16/wcd-2019-16.pdf Thank you and the others for sharing their knowledge.

To me it seems, this in line with EC46 of this night.

I'm not Lorenzo either, but I think you have to watch the work of Domeisen. In this chart you see the downwelling divided in 4 regimes. Right now we have blocking. This means there will be 2 significant downwellings after this one. This doesn't mean winter at the British Isles or at home in the Netherlands, but increased chance of negative AO.

Well, we all have our preferences. In my opinion the cold on the eastside of the anticlone will erode it. Probably the area of low pressure at Scandinavia will push southwest, making it harder (longer way) for cold air to reach NW-Europe.