(Updated 5/Jan/2015) State of the Polar Vortex. Broken? From 29 Nov 2014 to 5th Jan 2015 (by Diego Fdez-Sevilla)
Last 22 of Nov the Polar Vortex at 10 hPa showed a configuration of two vortices. This configuration didn´t last for long. Few days later the Polar Vortex regained a single vortex configuration. However, when we consider the configuration of the lower part of the polar vortex, at 70 hPa, this has been divided frequently in two vortices since before the 22 of Nov, and it continues divided most of the time.
So the Polar vortex at 10 hPa seems to behave splitting in two and regaining its single configuration after a couple of days. Will this behaviour repeat throughout the whole Winter or will the Polar vortex break lasting for more than a couple of days?. Well, I will try to keep an eye on this and share what I see.
And yet, Would that change anything in the patterns that we have seen already in the weather across the North Hemisphere without the Polar vortex being broken? (more discussion on this issue here).
The following images show the state of the Polar Vortex on 29th Nov 2014. Images from Nullschool,net. On the 29th Nov 2014, the Polar Vortex showed at 10 hPa a two vortices configuration once more (images below).
(UPDATE 30 Nov 2014) Today 30th Nov 2014, The NOAA and Nullschool show the Polar Vortex with a two vortices configuration at 10 hPa.
I am not a meteorologist so I can only observe, learn and try to analyse and share what I see. At this moment there are already weather events which have their origins open for discussion. Normal variability or forcing related? Are they the result of increased concentrations of atmospheric CO2 and water vapour?.
So far, since October, there has been a deep H in the Atlantic (taking from 1000 hPa to 250 hPa and higher) which has played a big impact over the Jet Stream circulation. This situation continues at the present time.
Generally, a H in the Atlantic and another H moving from west to central Pacific, together with the H in California, have been very resilient features since the beginning of October. Also, the polar vortex has been consistently broken in two in its base at 70 hPa, the closest to interfere with Jet Stream circulation. The circulation of the Jet Stream has been diverted across latitudes by so many L and H systems that some days, part of the Jet stream has been diverted so into the South that it has crossed over the equator, into south hemispheric circulation.
We have seen already the Jet Stream wobbling without the Polar vortex being broken at 10 hPa so, will a broken polar vortex make any difference? For more discussion check previous related posts at the bottom of this post.
Coexistent Weather events highlighted in the media:
26 Nov 2014. Met Office. Severe weather around the world
While the UK is currently experiencing relatively benign weather for the time of year, extreme conditions are expected in some other parts of the world.
Morocco and Spain
Last Saturday, Agadir in Morocco saw 90mm of rain fall in just 24 hours, which is around twice the monthly November average for the region of just 50mm. The subsequent flooding resulted in more than 30 fatalities.
Unfortunately, more severe weather is expected through Friday and into the weekend across Morocco, but particularly around the southwest of the country.
A combination of a deep area of low pressure, relatively warm sea temperatures and strong winds will bring heavy rainfall. 100-150mm of rain could fall across SW Morocco on Friday with further heavy rain likely on Saturday, and totals could be enhanced over higher ground. Conditions should improve into Sunday.
Through the weekend, the same area of low pressure is expected to bring very heavy rain across North East Spain. Rainfall totals for both days could reach 150-300mm, locally 400mm over higher ground, with a gradual improvement into start of next week.
Both areas could experience flooding and landslides from the intensity and duration of rainfall, as well as the rain that has already fallen in recent days.
The storm started at 5am this morning and according to sources at the State Meteorological Agency (AEMET) the tornado was produced between 7am and 8am.
A small tornado with winds of between 140 and 180 kilometres per hour (86 and 111 miles per hour) struck the Churriana distict of Malaga and Playamar in nearby Torremolinos on Thursday, causing considerable damage to properties and vehicles.
29 Nov 2014 All warnings for Spain.
The general map contains a summary of all the severe weather hazards respectively severe weather warnings as well as useful weather advices for Spain. On the map you can see at which locations respectively in which areas of Spain severe weather events as gale/storm, heavy rain, heavy snow, thunderstorm or freezing rain are imminent. Furthermore, the overview indicates where in Spain extreme temperatures or icy roads / glazed frost have to be reckoned with.
We distinguish between weather watches and weather warnings. Severe weather watches are issued up to 48 hours in advance, if the occurrence of a severe weather event is probable but there are uncertainties about duration, intensity and/or the course of this severe weather event. Severe weather warnings are released if meteorologists are certain about the occurrence of the severe weather event. Thereby, three levels are distinguished: The orange warning level stands for a (upcoming) moderate severe weather event, the red warning level for a strong severe weather event and the violet, top warning level for an extremely strong severe weather event in Spain.
5 Jan 2015. (Met Office) Extreme global weather. Link here
The UK may be experiencing what looks likely to be a milder than average winter but other parts of the globe are struggling against some extreme weather conditions.
Heavy snow is expected to affect large parts of Turkey, Georgia, Armenia and SW Russia early this week. As the cold conditions spread east later in the week, strong to gale force winds and heavy snow are expected across more eastern parts of the Mediterranean. For more follow the link.
North America and Canada
Large areas of the USA and Canada are experiencing very cold conditions, with the threat of heavy snowfall across some parts over the coming days. For more follow the link.
Will the US weather affect the UK?
The cold conditions will have the effect of strengthening the jet stream, which will move close to the UK over the coming days. This will bring unsettled conditions through this week, with spells of wet and windy weather, particularly across northwestern parts of the country. However, it will be mild, particularly towards the end of the working week when daytime temperatures could reach around 14C.
There is the potential for the remnants of this cold air to move eastwards across the Atlantic to affect the UK over the weekend. However, the airmass will become heavily modified by the Gulf Stream, and there is little risk of the extreme temperatures over North America affecting the UK.
Why is relevant to know about the configuration of the Polar Vortex?
“During extreme variability of the Arctic polar vortex termed a “weak vortex event,” anomalies can descend from the upper stratosphere to the surface on time scales of weeks. Subsequently the outbreak of cold-air events have been noted in high northern latitudes, as well as a quadrupole pattern in surface temperature over the Atlantic and western European sectors, but it is currently not understood why certain events descend to the surface while others do not.” “The subdivision of such events into vortex displacements and vortex splits has important implications for tropospheric weather patterns on weekly to monthly time scales.” “Using reanalysis data it is found that vortex splitting events are correlated with surface weather and lead to positive temperature anomalies over eastern North America of more than 1.5 K, and negative anomalies over Eurasia of up to −3 K. The corresponding signals are weaker during displacement events, although ultimately they are shown to be related to cold-air outbreaks over North America.” Mitchell et al. 2012 – Paywalled
(Update 1/Dec 2014)
(Diego Fdez-Sevilla) NOAA and Nullschool data agree showing two Vortex at 10 hPa and 70 hPa. Will that make any difference in the behaviour of the Jet Stream from what we have seen already? My guess is not. The stability of the Polar Vortex configuration and the steadiness of the Jet Stream have shown already to be very weak (see previous posts Why there is no need for the Polar Vortex to break in order to have a wobbling Jet Stream and polar weather? (by Diego Fdez-Sevilla)).
Such scenario makes me think that the strength of the Polar vortex reflect atmospheric conditions being built from the bottom up and not the other way around. With such consideration the factors affecting the behaviour of the Jet Stream, and weather events associated, would come from processes being happening below the Polar vortex, allowing to generate strong L and H systems. Feedback and Thoughts on this are wellcome.
Since October, there has been a deep H in the Atlantic sea (taking from 1000 hPa to 250 hPa and higher) which has played a big impact over the Jet Stream circulation, dividing it in two. This impact over the Jet Stream from the High pressure in the middle of the Atlantic continues now Feb 2015. Another H tilting from west to central North Pacific, together with the blocking H in California, have been very resilient features. But also, systems of Low pressure have been generated frequently taking from 1000 hPa up to 250 hPa over the central North Pacific Ocean, strong enough to interfere with the Jet Stream and resilient enough to create blocking patterns influencing meteorological conditions across North America.
Altogether it makes me wonder, Where are those systems taking the energy from so they can compete with the Jet Stream for space in the atmosphere?
Two forms of energy have being constantly increasing in the atmosphere, without oscillations, CO2 as a Greenhouse gas absorbing heat and Water Vapour adding latent heat and mass. Those forms of energy are linked with adiabatic processes inducing transformations from one form of energy to another. From absorbed heat by CO2 and Water vapour into Kinetic Energy and from water mass into Potential Energy, rain fall, hail and snow. All this energy being introduced in the atmosphere might not change the Climate but pretty well might change weather systems, and therefore, weather patterns.
If in the last year’s winter 2013/14 we discussed how the Polar vortex configuration could induce changes in the lower Jet Stream and weather events, at this moment, based on observation (see related posts) I am considering worthy of discussion the possibility of facing a bottom up chain of events. That is, the Jet stream steadiness gets wobbly due to the interaction of atmospheric systems resultant of adiabatic processes strong enough to divert and even split the Jet stream path. That would induce instability in the base of the Polar vortex which in turn it would break into more than a single vortex. Using the imagination, it would be a pattern of vortexes following the configuration of a root from the bottom up. More splits at the base would increase the number of junctions found high in the atmosphere.
How is it originated the Polar Vortex.
Planetary Vorticity is “generated by the rotating earth”, it “is zero at equator”, is at it’s “maximum at pole (one revolution per day)” and “is always positive (cyclonic [counter-clockwise in the northern hemisphere])”, Lyndon State College Atmospheric Sciencesi.e.:
Polar Vortices are “caused when an area of low pressure sits at the rotation pole of a planet. This causes air to spiral down from higher in the atmosphere, like water going down a drain.” Universe Today
“The polar vortex extends from the tropopause (the dividing line between the stratosphere and troposphere) through the stratosphere and into the mesosphere (above 50 km). Low values of ozone and cold temperatures are associated with the air inside the vortex.” NASA
Below is Northern Hemisphere Area Where Temperature is Below 195K or -78C, and it shows very cold air within the Polar Vortex descended from 10 hPa/mb – 31 km – 102K feet down to 250 hPa/mb – 10 km – 34K feet, twice during January, 2014.
(I believe that any hypothesis that I present here can help to understand present and possible future scenarios in atmospheric circulation. However, these are assessments based on observation which need to be validated throughout open discussion and data gathering.
I would like to not only be the one proposing theories but also be involved in these lines of research. Since I am in a transition period looking for a position in research, I don´t have the time and access to gather and analyse the data needed to settle some of my points of view. So I publicly ask for feedback as well as institutional and economic support to find the means to contribute evaluating the accuracy of these assessments. So please feel free to incorporate your thoughts and comments in a constructive manner.
Please, if you feel like sharing this post and generate discussion about it, I would appreciate to have a reference about the place or platform, by private or public message, in order for me to have the opportunity to join the debate and be aware of the repercussion which might generate d.fdezsevilla(at)gmail.com)
- The Polar Vortex breaks again in the North Hemisphere 22 Nov 2014. (by Diego Fdez-Sevilla)November 22, 2014
- Why there is no need for the Polar Vortex to break in order to have a wobbling Jet Stream and polar weather? (by Diego Fdez-Sevilla)November 14, 2014
- (Updated 19_Nov) New theory proposal to assess possible changes in Atmospheric Circulation (by Diego Fdez-Sevilla)October 21, 2014
- What type of Polar vortex configuration can we expect for this winter? (by Diego Fdez-Sevilla) October 7, 2014
- Met Office. The Recent Storms and Floods in the UK (Feb 2014) (by Diego Fdez-Sevilla) February 17, 2014
- The breakdown of the Polar Vortex. It happened before so, What would follow? (by Diego Fdez-Sevilla) March 14, 2014