2013 Polar Vortex Collapsing; Complete Disintegration Possible!!! US, North Europe, Midle East Hit!!!

You gotta be joking !
Are you in Portugal ?
Check weather models, ecm gfs, nogaps, ukmo you name it
Temperatures are above average where you say you live .
Don't get mixed or mix things up with with the US and or Canada

A fact is a fact !

much welcome my friend! :)

mas ja viste o ultimo modelo que saiu? o link está atrás.

Os modelos mostram um grande potencial para o frio. Melhor prevenir do que remediar!

(The models do show a great potential for cold. Better safe than sorry!)

What would you rather do...

Be sitting in the cold?

or enjoying some nice hot wet kona?
[link to www.konacoffee.com]

Prep for the worst... hope for the best



Most will not know the humor of the above

I don't speak much Portuguese although I now working in Setubal (south of Lisbon) but the FACT is temperatures have been warm, and YES water temperature has been high
Same has happened and is happening in various parts of Europe.
You're mixing it all up, you post models that do not reflect your local weather that's all.
Again you're not in North America this is almost Africa !
No such weather model forecast any cold snap for Portugal atm, so sleep easy as there ain't no need to grab your pillow

Do you know that Kona in portuguese is pussy?

ha ha ha ha


nothing will keep you warmer than some hot kona lol lol






Last Edited by Dr. Acula on 12/30/2012 05:28 PM

OK kind of understand it..lol...

Shwing!

Posted Today, 11:18

GFS 06z forecasts for the polar high to emerge over Greenland at 30hpa for d15, which is very encouraging-
In all forecasted regions of the strat, the secondary warming (that at 30hpa stems from a polar high 'push' in the arctic ocean area) will take the vortex energy from NE Canada to Alaska- transporting most cold energy and also weakening the vortex substantially (even at 100hpa)- as shown by the d16 forecast
The response would be for a gradual shift towards heights to the north (Iceland-Greenland-Svalbard), with weakening energy moving progressively west in the medium term in Canada. The lingering vortex at 100hpa then transports from Siberia into Scandinavia and western Russia by d14- and so the likely shift to MJO phase 7 (from 6-- watch EC 240 this morning) and the likelyhood of retrogressive motion in our locale (as touted by the GFS) towards Greenland

Tropospheric response is pretty sharp on the ball- I would say the likelyhood of colder conditions setting into much of western and northern Europe increases significantly from around the 12th of January. [link to forum.netweather.tv]

Posted 28 minutes ago

Luisport, on 31 December 2012 - 13:02 , said:


Please can you tell me something about situation for south europe, specialy Portugal and Spain? Thank you so much.


It is too far out to be able to tell, but the outlook might be for a cooler spell. It seems possible that spain and portugal could have atlantic maritime air circulating via the UK or possibly scandinavia (see charts below). I guess temperatures might just dip below freezing over night, but charts are not at the moment suggesting anything exceptional for Portugal and Spain. Now if you were looking at Greece, Italy or North Africa then you might expect an unusually cold spell. See wind directions on the charts below.

These charts are at the limit of model forecasting and will most likely be substantially wrong. At the moment the best we can honestly say is that there is potential for some cooler weather. [link to forum.netweather.tv]

Monday, December 31, 2012Stratosphere Analysis and Forecast - December 31, 2012
By Andrew at 1:39 PM
Model forecasts, specifically the ECMWF, continue to show increasingly-supportive signs for a polar vortex split. The ECMWF model shows two daughter vortices emerging 10 days out, one centered over northern Eurasia, and the other centered in Canada. High pressure separates the two. That is in the lower stratosphere. In the upper stratosphere, complete collapse of the polar vortex is being forecasted, with potential vorticity forecasts coming down to values that indicate the polar vortex is no longer supported in that stratospheric level, as forecasted below:

For those familiar with different levels of the stratosphere, this is the 10 millibar forecasted potential vorticity at Day 10. While there is a formidable area of potential vorticity (PV) values in western Europe, it's not nearly enough to support itself. Another extremely weak vortex is found in east Canada but again, it cannot support itself.

This is the isentropic leve; 475 K forecast for PV values at Day 10. Because the millibar equivalents are not listed, I believe this level is in the mid-lower portion of the stratosphere, meaning a vortex collapse here would be more significant than a collapse in the upper stratosphere. Anyhow, this forecast shows a full split has happened with the polar vortex, and two vortices have emerged. One is in far north Canada, and the other is an elongated vortex stretching across Eurasia. The second vortex is more significant because it is the dominant vortex in this situation. However, looking at the Day 7, 8 and 9 forecasts for this same level tells me the superior vortex appears to be on a weakening trend in this forecast. The perpetrator appears to be that dark blue finger of very low PV values pressing across the North Pole. This appears to be solidifying a split of both vortices, ensuring that the polar vortex is then more prone to collapse instead of being one vortex.

This zonal wind forecast for that Day 10 timeframe shows negative values from 70N - 90N, and positive anomalies across the rest of the board. Now, that huge negative anomaly signifies winds that go against the polar vortex. The presence of blue colors is bad for the polar vortex, so to see a swath of such a large and deep negative wind anomaly tells me the polar vortex is not going to catch a break anytime soon. I want to also point out that small finger of blues between the 30 millibar and 100 millibar areas on the far left hand part of the image. That is another wind-based phenomenon called the negative QBO. Without going too far into detail, the negative QBO creates a naturally-unfavorable situation for the polar vortex, because, once again, winds are going against the polar vortex.

This has significant implications as far as cold potential goes in January and February. The polar vortex will split, and that is the crucial step that then opens us to the potential of an overall collapse. Based on these zonal wind forecasts and PV forecasts, it looks like this split will be sticking around for a while. I am seeing potential for another warming in the next 2 weeks, but that remains to be seen.

And last but certainly not least, we need to wach the 10 millibar layer. Towards the end of the animation, you can see a sudden stratospheric warming blossom in the subcontinent of India. The angle of this warming tells me it may be trying to make a move towards the Arctic, but that certainly remains to be seen as the SSW occurs, surrounded by much below normal temperature anomalies. If this does propagate towards the Pole in the next week, late January-early February will only look colder.

In summary, my confidence is only growing in how the stratosphere will begin to buckle dramatically in the next 2-3 weeks. Model forecasts confirm my beliefs that all levels of the stratosphere will sustain heavy damage, and the upper stratosphere polar vortex looks like it will collapse. Very long range GFS model forecasts have been trending solidly with no polar vortex present in the 1mb, 2mb, 3mb and 5mb levels. The 7mb, 10mb and 20mb levels have their polar vortexes greatly displaced, and the lower stratosphere is experiencing splitting, not extreme displacement. Should this happen, the back end of winter will be cold. Not cold as in time to bring out the heavy jackets, cold as in highs in the negative digits (in places that do not usually experience such temperatures). If the vortex collapses... well, just remember what happened in January 1 [link to theweathercentre.blogspot.de] 985:

Temperature Anomalies from January 20 - January 22, 1985
Andrew

It appears that the recent storm train that has brought heavy snow to many areas of the central and east US will be shutting off for a while. An example of the forecasted situation above is shown by the GFS Ensembles, with high pressure barricading storms from moving into the US from the Pacific. This barricade should hold for the next several days before it breaks and storm chances ramp up again.

This storm train breakdown will lead to warmer temperatures prevailing across much of the nation, including the Plains, Midwest and rest of the North US. It is expected temperatures will get as high as 10 degrees above normal, but a lack of warm fronts from storm systems means warm ups will not be extreme (i.e. 20 degrees above normal).

Again, this is only temporary, but it does bring a wake-up call that a continuous storm train can not and will not run on and on. At some point, the storms have to cease for a while. The worry is how long they will cease for.

Andrew [link to theweathercentre.blogspot.de]

19-11-2012, 19:05
Redsunset

Moderator
I've taken the following info from an Italian website and it helps to explain in particular the Brewer Dobson Circulation. Talks about the QBO and solar influence on Strat. Please pardon some translation errors.

SOLAR ACTIVITY and QBO

With regard to solar activity, the situation is quite poised and therefore difficult to interpret. We know that the activity of our star, despite being "near" the phase of maximum, remains relatively low values, with the solar flux that oscillates almost periodically for months between 100 and 140. In an attempt to better frame the "sunshine state", let us understand some of the mechanisms by which solar activity affects the Earth's atmospheric circulation, referring to the top of world research (Durkenton, Hood, Labitzke, Salby and Callaghan etc. .. ). direction and intensity of equatorial stratospheric winds tropo-play a key role in the modulation of the Polar Vortex winter (VP), and therefore the climate at mid-latitudes.

Direct evidence of this comes from Quasi Biennial Oscillation (QBO), which corresponds precisely to a periodic oscillation of the stratospheric winds in the tropics: the evolution of these winds, as is well known, is one of the leading "regulators" intensity of the VP. Now, without going into too much detail (return to talk about these interesting topics in a more appropriate location), in the last few years has been identified a mechanism by which solar activity can influence the performance and strength of the equatorial stratospheric winds , thus interfering heavily on the strength of the VP. This mechanism is based on the variation of the emission of ultraviolet rays between maximum and minimum solar and its interaction with the production cycle of stratospheric ozone. In this regard it is necessary to clarify beforehand two fundamental concepts:

1) in relation to solar radiation, the only village that varies "heavily" between maximum and minimum solar ultraviolet light (also 7.6 percentage points), while all other fractions tend to vary significantly lower quantities of (the TSI in the cycles of the twentieth century to more than 0.1%).

This figure shows the emission intensity of ultraviolet (UV) during cycle 22 and 23. As can be seen, between maximum and minimum solar, there are significant variations (of the order of 6%).This fact led major research centers worldwide to focus on ultraviolet radiation to explain the very short-term climate change that occur in the northern hemisphere over the years characterized by low solar activity (as happened in recent years);

2) most of the ozone production occurs in tropical stratosphere, where it is stronger and is always present solar radiation. Ozone is created in this region as it is here that the sun, this all day and throughout the year, it is more intense flows solar (UV) break oxygen molecules (O2) into oxygen atoms (O), which react rapidly with other O2 molecules to form ozone (O3). All these reactions are highly exothermic, leading to radiative heating of the high tropical stratosphere, where there is the main area of training ' ozone. The main consequence of the radiative heating the thermal gradient is positive with increasing height (in contrast to what occurs in the troposphere), and therefore an increase in the stability of the stratosphere same. Ultimately, the reduction of the amount of ultraviolet radiation that occurs in the years of low solar activity, is due to a reduction in radiative heating: this makes the stratosphere colder and unstable (it reduces the thermal gradient positive with increasing height).

This fact, by binding with the thermal wind, produces a weakening of the zonal wind (U) in the mesosphere-stratosphere high tropical going to interact with the westerly regime of the SAO (semi-annual wind oscillation), which precisely in the months in which form the stratospheric polar vortex reaches its maximum value (October-November). The abnormal weakening of the SAO is very important for the following reasons: • it was noted that the weakening of the zonal stratospheric winds in 'high tropical stratosphere is associated with a weakening of the zonal wind within the Stratospheric Polar Vortex (VPS), particularly during the period in which they recorded their maximum (solstice ' winter) . In other words it has been observed that statistically, when the zonal wind in the mesosphere / high tropical stratosphere are less intense, the VPS tends to be weaker in the first part of the winter;• there is a relationship between the regime of the SAO and the QBO. Specifically, in the years of QBO negative, the weakening of the SAO produces, over the entire column stratospheric, twenty easterly of greater intensity (absolute value of the QBO higher) with a consequent increase in the duration of the phase.

It is no coincidence that all the episodes of QBO strongly negative (values below -23/-24) were recorded only in the years of low solar activity. these circumstances (increased intensity and duration) are essential given the importance that covers the QBO negative action of disturbance to the detriment of future Stratospheric Polar Vortex. In this regard it should be noted that when the wind regime is stratospheric tropical eastern tropical easterlies tend to restrict the width of the planetary wave-guide in the extratropical lower stratosphere, favoring a larger amplitude wave and a lower phase velocity.The result is an increase in wave propagation in the stratosphere, thus heating and slowing down the VPS.discovery of these dynamics, although constitutes a major step forward in the understanding of the phenomena of "transmission" of the solar signal, does not yet allow to explain fully the real mechanism of coupling between the high stratosphere tropical lower stratosphere-troposphere tropical and polar stratosphere.

It is no coincidence that the simulation models ("GCM simulations"), while showing consistent results with theoretical predictions, are still substantial differences with the experimental measurements. This suggests that there are additional retroactive phenomena can strongly amplify the response of the atmosphere with respect to the primary signal "photochemical" Variable-induced solar, thus playing an important role in coupling: one of these is definitely the Brewer-Dobson circolation (BDC).

In the past we have already had occasion to speak of this "fascinating" meridian circulation. Briefly recall that the BDC, so named for its discoverers Brewer and Dobson, is a slow circulation in the stratosphere and hemispheric agent arranged along the meridians. This circulation is responsible for the movement of air particles from equatorial regions up to the polar regions and is most active in the northern hemisphere. In particular, this movement is characterized by ascending motions in the equatorial regions and descending motions in extratropical areas (especially in the northern hemisphere polar). The action of the BDC produces some basic effects: • thanks to the vertical transport of chemical species and southern, mainly including ozone, BDC greatly influences the chemistry of the polar bear.transport of ozone to the north pole ricompre, including other things, a great importance for the fate of the second half of winter (mid-January onwards), since, with the arrival on the pole of the first solar radiation, ozone absorbs most of the solar ultraviolet radiation and the returns in the form of heat, favoring the development of phenomena of stratwarming and making the VPS weaker; • the vertical motions associated with the BDC have important consequences for the distribution of temperatures in the stratosphere.

Indeed, due to the action of the BDC, the tropical tropopause is the coldest region in the troposphere and stratosphere. This is because the air in the tropics lifts cools to adiabatic expansion, bringing the temperatures of the tropical lower stratosphere well below the equilibrium temperature radiative local. In this regard, since the BDC is stronger during the northern winter, the strength of the air lift (upwelling) in the tropics, and then the low temperature of the tropopause trope-equatorial, presents an annual cycle, with values records during the 'northern winter.

On the contrary, in the polar region, the descending air is heated by adiabatic compression, bringing the temperatures in the stratosphere polar to several tens of degrees above the local radiative equilibrium. The latter circumstance favors the heating and greater "instability" of the stratosphere polar also in the early stages of winter

Figure constitutes a schematization of the BDC. diagram of operation of the BDC is quite complex.

In the first analysis we might expect a mechanism type Hadley cell, in which the circulation originates from the tropics solar heating and cooling in the polar region and is characterized by a large transport of warm air ascending (tropical) towards the colder regions (where the air goes down).

Actually BDC been closely related to the action of planetary waves (Rossby waves) in the extratropical stratosphere. Indeed, when stationary planetary wave reaches the stratosphere, deposits its time Esterly, decelerating the jet stream which is westerly stratospheric winter. On these occasions the polar vortex slows down and can also be moved. The deposition of momentum in the east polar stratosphere and the resulting slowdown in the winter polar jet is known as "breaking wave". This condition produces friction the stratospheric sudden warming phenomenon. The result is a situation that is thermodynamically unbalanced.

At this point, to restore the balance radiative, starting from high stratosphere quickly starts a process of cooling. The cooling air is accompanied by movements within, as the cooler air is denser and sinks. And it is precisely this movement that determines the movement of air along the meridian from the equator to the pole hemisphere winter . In fact the air descending in the polar region must be balanced by a flow of air towards the moving toward the poles. Requirements for earth continuity, this air must come from the tropics. The BDC is therefore that cell movement in which the tropical air moves towards the poles to replace air descending to the poles.

Now that we have more clearly one of the key mechanisms of solar activity, along with the QBO modulates the intensity of the polar jet, we are certainly capable of better managing the current situation. Indeed, we understand that, to be able to decipher ' current "solar puzzle", the parameter that should be monitored with particular attention to the intensity of ultraviolet radiation arriving on earth. To do this we consider the flows at wavelengths equal to 205 nm, as are those which can penetrate up to an altitude of 30 km, or up to the border area between the mesosphere and the high stratosphere tropical (this is the altitude where there is maximum production of ozone).

Below is a graph then from which you can infer the performance of UV rays on the last year: To be able to "quantify" the intensity of the current flow, we use as comparing the performance of UV rays recorded during the solar minimum in between cycles 22 and 23 (1995-1996): As you can see we are practically at the same level, so we can say with reasonable confidence that the current situation may be considered more from minimum to solar maximum.Responding to this trend of UV rays, the QBO is clocking negative values of respect. Specifically, in reference to the proportion of 30 hPa, for two consecutive months (July and August) was marked by an almost record (-28), while in the next phase (September-October), despite the passing of the peak, the QBO remained still at very low levels (around -25). E 'likely that the current cycle of the QBO negative is particularly long. In fact, in reference to the amount of 30 hPa, if the change of sign you will have in February (as one might expect), the current cycle will be composed of no less than 18 consecutive months of easterly regime (QBO-). As regards instead the QBO to share 50hPa, what is practically certain that the change of sign will occur to winter completed. So we can conclude that, even as regards the QBO, the situation in view of the winter is decidedly positive.

Finally, Always with reference to the QBO, we wanted to make you note that the current situation is very similar to the one it had in the period 1984-1985. Even at that moment the QBO in 30hpa did mark a significant peak (still -28) at the end of the summer (in that case in September).Obviously we can not use this information as an indication of the progress of the coming winter, but surely it is a "coincidence" to watch, especially considering that in that period the solar activity appeared weak.
[link to www.boards.ie]

Strong jet steam spawned superstorms in December

Posted on January 1, 2013by The Extinction Protocol


January 1, 2013 – CLIMATE – The weather outside was truly frightful across much of the US and UK this holiday season. In the US, a powerful winter storm whipped up heavy snow, icy winds and a record number of tornadoes in late December, causing at least 15 deaths. Such storms are not unusual at this time of year, but an especially strong jet stream made the storm more intense, says meteorologist Greg Carbin of the US National Weather Service. “One of the more remarkable places was Little Rock, Arkansas,” says Carbin. “It shattered the prior record for snowfall on Christmas Day.” Little Rock, which hadn’t seen a white Christmas since 1926, was hit with more than 25 centimeters of snow. At the same time, warmer air mixing with the southern border of the system created thunderstorms along the Gulf Coast that spawned 34 tornadoes across four states. The storm then churned north-east, dumping 30 cm of snow or slushy mix on parts of the Midwest and New England. Thankfully the storm was fairly fast moving. “It was pretty much a one-day event in any region of the country,” says Carbin. In the UK, heavy rain saw many rivers burst their banks and roads and railway lines washed away. It is the inevitable end to what looks like being the soggiest year since records began. -New Scientist [link to theextinctionprotocol.wordpress.com]

current warming in progress [link to forum.netweather.tv]

I don't know if this helps, but these are posted on my local Indianapolis, IN weather blog this morning for US:

"The next week is looking fairly quiet with no major storms. The long range models are hinting at a nice warm-up by the beginning of next week. We could see highs in the 40s by the middle of next week.

December turned out to be warm and snowy. In fact, it turned out to be the 7th snowiest on record. Check out the new January outlook that was issued yesterday."

[link to blogs.wishtv.com] monthly temps image

[link to blogs.wishtv.com] monthly precip image

[link to blogs.wishtv.com] main blog

we have to wait untill we know for shure what this PV collapse will give to the end of this month and February...

Tuesday, January 1, 2013Could The Polar Vortex Collapse Like January 1985?
By Andrew at 11:55 AM
I have been calling for a polar vortex breakdown and possible collapse for a while now, and I now think it is time to introduce the possibility that January-February 2012 could resemble the infamous January 1985.

We'll start with a flashback to December 1984, image courtesy of weatheradvance.com. In December 1984, we saw strong high pressure to the north of Greenland, along with low pressure stretching across the Atlantic and low pressure in the Southwest. High pressure also prevailed across the Gulf of Alaska, and low pressure was present in the Bering Sea. I want you to keep an eye on that low pressure in the Southwest and high pressure in the GOA for our next image.

This is what the GFS Ensembles showed as of this morning's 12z run at initialization, also known as Hour 0 in the forecast. We see high pressure trying to squeeze into the Gulf of Alaska, low pressure in the Southwest and slight high pressure in the Pacific Northwest. Looking back at the first reanalysis image of December 1984 we find a similar small signal of a high pressure in the Pacific Northwest. Worth noting is the presence of strong high pressure across north Asia, in a very similar position to the one seen in the reanalysis image. Low pressure does not extend across the entire Atlantic, but let's not worry about that specific piece right now. We have now established a few good links to December 1984.

This reanalysis image, once again from weatheradvance.com, shows what the month of January 1985 was like as a whole. We saw high pressure dominating the northeast Pacific, low pressure in Asia, and a strong high pressure regime in the Arctic, which appears to have been a base for the exile of the polar vortex. Low pressure was found in the Plains and general North US as the polar vortex was displaced south.

Here's the strikingly scary part- the long range forecast from the GFS Ensembles closely resembles this reanalysis image. We see high pressure in both the northeast Pacific and north Atlantic. Low pressure is present in the Bering Sea and Eurasia. A triangle of high pressure systems from the Pacific, Atlantic and Arctic shows that we are once again looking at a potential exile of the polar vortex. Look closely at the US. Slight low pressure is forecasted in the North US in an eerily similar move to January 1985. The center of the polar vortex, placed west of Greenland and shown as several ovals, is in almost the exact same spot as the polar vortex in December 1985, once again shown as several ovals.
This is a perfect situation for the polar vortex to slip south- the atmosphere is practically rolling out the red carpet for the polar vortex to dip into the United States. With the triangle of high pressure barricading off Europe and the Pacific as possible exit points for the polar vortex, a lack of high pressure in North America is essentially a welcome mat. Low pressure does not go towards high pressure.

Let me set the record straight- I am not calling for another January 1985. What I AM saying is that signs are pointing to a SIMILAR set-up as January 1985. That in NO WAY means the polar vortex will once again slip south- it means the potential is there, but NOT CERTAIN.

Andrew [link to theweathercentre.blogspot.de]

Complete Polar Vortex Breakdown Likely
By Andrew at 3:47 PM
I have been saying that the polar vortex is looking unstable, that it will sustain heavy damage, but I am now putting out the call that the polar vortex will suffer a breakdown in coming weeks.

A 50mb animation of temperature anomalies shows we are seeing that sudden stratospheric warming (SSW) ongoing across Canada and the Arctic at this time. This comes after a previous SSW in the opening days of December. But I want to point something out. Watch the last few frames of this animation. See how that warming starts to propagate towards Japan? This could be a second warming that may strike as the current warming is ongoing. Based on how the Japanese warming cell's contour lines are expanding northeast towards the ongoing SSW, I see reason to believe this Japanese cell of warming may also move towards the Arctic and strengthen the ongoing SSW.

Here's what I want to watch as far as model forecasts go. I am staying with the ECMWF model today out of confidence over the GFS, and because it displays information better than the GFS. Let's start with the far upper stratosphere.

This is the 1 millibar forecast for the stratosphere over the Northern Hemisphere. The US is on the left side of the image; you can make out the shape of Alaska in dark blue. I want to point out the main attraction, the big red blot over Europe. This is the warm air from the SSW. It is doing significant damage to the polar vortex, as I went back a few forecast timeframes and found significant weakening with every 24 hour image. This confirms my theory that the polar vortex will most likely collapse in the upper stratosphere first, if there is a stratosphere collapse to be had.

I'll show these next two images together due to their similarities.

The top image is the pressure and temperature forecast at 20 millibars, and the bottom image has the 50 millibar forecast. We want to pay close attention to the pressure lines here. Both images show two areas where there are multiple enclosed circles and/or ovals. These are daughter polar vortices. They signify that the main polar vortex has split and made multiple daughter cells. In both images, one vortex is over Canada and the other covers Eurasia. The reason these two images are significant is because the vortices are so far apart, and the split is so massive that I find it hard to believe the polar vortex can fully recover from this. The vortex is on its knees at this point- one more good SSW and collapse of multiple stratospheric levels of the polar vortex appears probable.

The last two images to show involve potential vorticity, or PV. In areas of raised PV, low pressure systems are commonly found, in this case the polar vortex (vortices). The top image shows presumably the PV values for the middle of the stratosphere, while the second image shows PV values for the upper stratosphere. Let's analyze the upper stratospheric image first (bottom image). We see two areas of slightly raised PV, indicating two daughter polar vortices. But they are so weak that they don't even constitue themselves to be fully-functioning polar vortices. This is what I call a good collapse of the polar vortex.
As for the top image in the mid-stratosphere, we see one compact vortex and one elongated vortex. The compact vortex is placed in Canada, meaning very cold conditions can be expected in that nation come late January-early February. The elongated polar vortex is the superior one here, but is gradually weakening per review of multiple forecast hours at this same stratospheric level. I believe weakening should continue with both polar vortices, seeing as even lower PV values are trying to funnel in the space between the two vortices. If that happens, the chances of reconciliation between the two vortices becomes lower, the chances of a collapse are raised.

The last image to show is a zonal wind forecast for Day 10, the same forecast time as the other forecast images. Here, we see three items of interest: 1) the oranges and reds in the middle of the image, 2) the blues in the right corner of the image, and 3) a finger of blues between the numbers 30 and 100 on the far left side of the image.
(1): The oranges and reds suggest winds in the stratosphere that are favorable for polar vortex formation and sustainment. The winds in the stratosphere are working to hold the vortex together in the areas where there are oranges and reds. The warmer the color, the more favorable the winds are to polar vortex sustainment. This spread of oranges used to cover the entire image, but has now eroded in the face of our next item of interest.

(2): There is a large body of blues in the upper right hand corner of the image. This signifies winds that are working against formation of the polar vortex. These unfavorable winds form when a sudden stratospheric warming occurs, as the entire purpose of the SSW is to disrupt favorable polar vortex winds and insert unfavorable winds in its place. These blues have been eroding as time goes on from Day 7 to Day 10 forecast time period, but the polar vortex favorable winds have also been eroding, meaning the potential breakdown's chances are on the rise.

(3): That finger of blues between the 30 millibar area and 100 millibar area shows yet another wind-based phenomenon in the stratosphere called the Quasi-Biennial Oscillation, or QBO. In a negative QBO, one encounters winds that are unfavorable to sustainment of the polar vortex, while the positive QBO brings about favorable polar vortex winds. Considering that finger of blues exists in the regions mentioned, I find a negative QBO to be in existence, another piece of the puzzle detrimental to the polar vortex.

In summary, the polar vortex is definitely taking multiple hits and will experience collapse in the upper stratosphere if these forecasts verify. If the split in the polar vortex continues and even strengthens, we could see a collapse in the middle and lower stratosphere later on in January, which would then make for a cold February. I will discuss that at a later date.

Andrew [link to theweathercentre.blogspot.de]

Recretos
Posted A minute ago

First just a little info about ECMWF:
After all the recent upgrades, the operational run has horizontal resolution 0.125°/16km, till 240h. Control run has horizontal resolution of 0.25°/30km all the way till 384h. Ensembles have resolution of 0.25°/30km till 240h, and 0.5°/60km from 240h to 384h.
Vertical resolution of the operational and the control run is 91 levels, with the top at 0.01hpa, while ensembles have 62 levels, with the top at 5hpa.

And just a side info, some recent model anomaly correlation skill comparison.

Ok, down the the real business.

Looking at the ECM forecast, it is obvious that the split will be evident in the mid and lower stratosphere, slightly before in the mid/mid-upper strat.

Looking at wave 2, it is evident lower in the strat, so it is kinda understandable. And it picks up toward the end of the period.

Now looking at the end of the period, the split is well evident in the lower stratosphere, all the way into upper troposphere, and I think even in the mid troposphere.

ECM operational, and the ensembles, are picking up the tropospheric response to the split with ease, with two ridge axis, one from Atlantic and one from Pacific, and well defined Polar Vortex split vortices. And GEFS isn't far behind either.

CFSv2 weeklies are now starting to pick up on these signals too, with week 3 possibly having a better SSW response.

Had to get it off my chest.

Best regards. [link to forum.netweather.tv]

:bumps:

:bumps:

Wednesday, January 2, 2013Multiple Stratospheric Warmings Confirm Polar Vortex Collapse Probable
By Andrew at 12:00 PM
I believe there is now solid evidence that a polar vortex collapse is probable in at least a few stratospheric levels in the next few weeks (for those wanting my definition of a collapse, see the last paragraph or two).

Part I: The First Warming
The first warming is ongoing, and has been ongoing for several days now. This sudden stratospheric warming is located in the mid-stratosphere at the 50 millibar level, as shown in the below animation:

The most intense warming is centered over northern Canada and the Arctic Circle, as shown by the highest maroon colored anomalies in the animation. This warming suggests even more warm air is being forced into the stratosphere, and the polar vortex should sustain damage from this. For those unfamiliar with the polar vortex, it is the low pressure system (vortex) that sits in the North Pole (polar) and holds cold air up. When the vortex is weakened, cold air tends to flow south. This is also known as the negative Arctic Oscillation.

We also use something called the EP Flux to measure what direction the 'wave' of this sudden stratospheric warming (SSW) is moving. Longer arrows with warmer colors tend to signal a stronger wave of this warm air. We can see how the SSW has evolved from the lower stratosphere to the upper stratosphere by December 31, the bottom right image. It is typical for the EP Flux to spike like this when an SSW occurs.

Part II: The Second Warming
After this first warming, it appears that we will be seeing a second warming in the next 10 days. Let's look at the zonal wind forecast from the ECMWF for Day 7:

In areas of negative zonal anomalies, you can find winds that favor the destruction of the polar vortex, while warm color winds tend to favor the formation and sustainment of the polar vortex. This is what the sudden stratospheric warming is- a change in winds. SSW's are indeed accompanied by these bursts of deep negative zonal wind anomalies which damages the polar vortex and can lead to cold outbreaks if the SSW is strong enough (which this one should be).

The two images above express 'waves' of geopotential heights. Wave 1 is on the top, and Wave 2 is on the bottom. In areas of warmer colors in either image, higher heights are observed, meaning high pressure has a tendency to form. In a similar situation, darker colors tend to indicate lower heights and thus low pressure areas form. Both images are forecast for Day 10. Let's start with Wave 1. Wave 1 will be going nuts over the SSW as it introduces high pressure anomalies to the upper stratosphere in response to the SSW. Again, going against the polar vortex (which is a low pressure system). By Day 10, because the First Warming is done, it will begin to die off. However, Wave 2 will begin to strengthen during that Day 10 timeframe, and this strengthening will occur through the upper and middle stratospheric levels, meaning that this second warming would theoretically have more of an impact across the whole stratosphere. In comparison, the Wave 1 had significant high pressure anomalies focused on the upper stratosphere.

This second warming should derail the polar vortex further to the point of a split, which we will discuss more on below.


Part III: The Split
By the time the second warming begins, the polar vortex has sustained enough damage that it must split into multiple pieces in order to sustain itself. This is shown in these ECMWF forecasts for different stratospheric levels:

5 millibar forecast for Day 10.
The 100mb level is closest to the troposphere (where we live), the 50mb layer defines the middle of the stratosphere, and the 5 millibar level is as far up the stratosphere I can get without putting up an image that resembles chaos, not a forecast.

I want to start with the 50 millibar layer. Think back to high-school biology for a moment. Recall that when cells divide, they originate from one parent cell and split into two daughter cells in order to make the object stronger (whether it be a cell wall (plant) or a cell membrane (animal)). Well, the polar vortex works similar, but not entirely the same. When the polar vortex is damaged, it will split into two vortices, called daughter vortices, in order to still maintain some control over cold air in the Arctic. When this split happens, it is not to strengthen itself like biology taught us, it is to keep itself alive, rather than experience a collapse in the single parent cell, resulting in chaos across the board. This 50mb layer clearly shows the split in progress by Day 7.

Now let's dart over to the other layers. The 5 millibar layer has a lot of things going on at once. In this case, there are actually three daughter vortices. One is located in Canada, another in western Europe, and the third vortice in Asia. They are all shown as several ovals tightened close to each other with decreasing numbers as you go toward the center of these ovals. The lowest pressure is identified with an 'L', in this case found over Canada. Also happening is a warming event, shown as the warmer colors in this image and happening over Europe and the Northeast US into the Canadian Maritimes. This will further weaken the vortices. High pressure has also built in over the Arctic in the absence of a single parent vortice, with the high pressure defined as an 'H'. The 100 millibar level does not show as severe a split or as severe a warming episode, mostly because the warming has been confined to the middle and upper stratosphere. However, if the geopotential Wave 2 forecast works out, that could change.

A few potential vorticity forecasts also show the split of the polar vortex:

Part IV: The Cold
There is roughly a 1-3 week lag time between a sudden stratospheric warming (SSW) and cold reaching the surface. Based on some research done, I feel that this timeframe should be more in the 2-4 week range this time around, which makes my expected arrival for the cold between January 22- January 27. This cold will persist for several days, especially if this second warming sticks around for a while. The weekly CFSv2 forecasts are showing such a sustained cold outbreak, as shown below in Week 3 (top) and Week 4 (bottom) temperature anomalies. ANOMALIES ARE IN KELVIN!

Look at all that blue- that's literally off the chart cold. The forecast is unable to produce any cooler anomalies, because the legend does not go any colder than that. The Week 4 forecast predicts temperature anomalies of 3.5 degrees Kelvin (roughly 6 degrees Fahrenheit) below normal across much of the nation. Significant warming in Canada suggests a continued weakening of the polar vortex may occur, along with blocking that may provoke a negative NAO, but that remains to be seen.

Part V: The Third Warming?
The GFS model is then pinpointing a third stratospheric warming in the long range, shown below:

10mb temperature at Hour 384.
Hour 384 is notorious for never verifying, but this warming forecast has been appearing on several GFS model forecasts, meaning the model appears more certain that this will actually happen, rather than not happen. The warming looks to originate over central Canada, right in the heart of a daughter vortice at that same 10 millibar level. That would only bring further weakening to the polar vortex/vortices and continues to confirm my suspicions of a collapse.

My definition of a collapse is as follows: "High pressure dominates the Arctic Circle, and any remaining polar vortices are weak and displaced to lower latitudes. A collapse is also believed to have happened if potential vorticity values are anomalously low." The definition of others' accounts of a collapse is different, but this is just what constitutes my posting of a probable collapse.

Things are looking up for a big cold outbreak in late January, an outbreak that could be sustained in the second and third warmings materialize and stick around for a while.

Andrew [link to theweathercentre.blogspot.de]

Brrr!!!

Thanks for the warnings, Luisport.

Have got all the wool gloves and hat on the ready.

Thank's!