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North Atlantic SST’s Dropping Sharply

December 29, 2015

By Paul Homewood 

 

The succession of storms passing our way in the last few weeks has had a noticeable effect on sea surface temperatures. Below is the current position, showing a huge pool of very cold water throughout much of the North Atlantic.

 

sst_anom

http://weather.unisys.com/surface/sfc_daily.php?plot=ssa&inv=0&t=cur

 

If we contrast with the maps at the end of October & November, we can see just how much this cold pool has grown.

 

sst_anom-151025

 

sst_anom-151129

 

 

It is this expanding pool of cold water which has been responsible for the jet stream moving much further south.

Below is the jet stream forecast for tomorrow, as Storm Frank passes through. Notice how far south the jet stream is forced, before turning sharply north.

 

hgt300

http://www.netweather.tv/index.cgi?action=jetstream

 

The Netweather forecast suggests that the jet stream will become much more zonal after Frank moves off. Below is the forecast for 8th January, which is reasonably typical for the next couple of weeks, and indicates that cold air will push south across the UK as high pressure builds.

(If you click on the link, it runs the animation).

 

  

hgt300

http://www.netweather.tv/index.cgi?action=jetstream

 

 

By looking at the SST’s and jet stream, it is clear why we have had a run of wet weather in recent weeks. And the culprit is that cold pool of water, not global warming. 

14 Comments leave one →
  1. December 29, 2015 2:44 pm

    Prettier pic at a clone of Cameron Beccarios’s earth.nullschool weather app.

  2. December 29, 2015 2:52 pm

    Unconnected maybe – but the cold water is roughly aligned with snowfall on one of windyty.com’s charts here

  3. December 29, 2015 3:16 pm

    Reblogged this on WeatherAction News and commented:
    That is one heck of a contrast with the Autumnal SSTs.

  4. Green Sand permalink
    December 29, 2015 3:20 pm

    Somebody else thinks change is on its way:-

    ‘Arctic Oscillation Analysis and Forecasts’
    December 28, 2015
    Summary

    “• The AO is currently weakly positive and is predicted to trend negative into negative territory starting next week.

    • The negative AO trend is reflective of the model forecast of initial low pressure/geopotential heights over the North Atlantic side of the Arctic transitioning to more high pressure/geopotential heights over the entire Arctic basin. The models are predicting two regions of strong geopotential height rises one across northwestern Siberia and the Barents Kara Seas and the other across Alaska and northwest Canada. This has significant implications for the strength of the polar vortex in January.

    • With high pressure strengthening in the Barents Kara seas, temperatures should turn cold first across Western Siberia and become more expansive with time. The models predict that first the cold air will expand westward toward Eastern Europe and then eastward across all of Siberia and eventually East Asia as well. How much of the cold air will reach Western Europe will likely depend on how much of the positive geopotential height anomalies will bridge across towards Greenland.

    • Similarly, rising pressure/geopotential heights across western North America will result in deepening troughing across eastern North America and a cooling trend in temperatures for the Eastern United States.

    • One strong pulse of energy transfer from the troposphere to the stratosphere that just ended over the weekend has perturbed the polar vortex and has helped to initiate the cooling across the mid-latitudes. The models are predicting a second pulse during the first week of January and we continue to anticipate even further energy transfer. This will continue to perturb or disturb the polar vortex further, which will likely peak sometime in January.

    • High snow cover and low sea ice this past fall favored a weakening of the polar vortex preferentially in January. Perturbing of the polar vortex is underway and in our opinion, the predicted hemispheric circulation pattern favors further weakening of the polar vortex. Following a weakened polar vortex, the negative phase of the AO, cold temperatures and potentially an increase in snowstorms is favored across the Northern Hemisphere mid-latitudes including the Eastern United States, Europe and East Asia………”

    https://www.aer.com/science-research/climate-weather/arctic-oscillation

  5. Don B permalink
    December 29, 2015 5:01 pm

    What struck me about the top figure is the huge pool of cold water in the northern Pacific. That has been the location of an unusual warm pool of water recently. The cool phase of PDO may be reemerging, with a vengeance.

  6. Howard Stein permalink
    December 29, 2015 5:24 pm

    “The succession of storms passing our way in the last few weeks has had a noticeable effect on sea surface temperatures.” & “By looking at the SST’s and jet stream, it is clear why we have had a run of wet weather in recent weeks”

    There appears to be a circular arguments here, I don’t understand the logic, what caused what ?

    • December 29, 2015 6:27 pm

      Storms absorb heat from the sea, via evaporation – thus reducing SST’s

    • David Richardson permalink
      December 29, 2015 8:31 pm

      The problem is Howard, that chicken and egg occurs a lot in the Atmosphere/Ocean interaction and in truth they modify each other in complex ways. The main reason we have been stuck with the current weather drift is the dominance of the Anti-Cyclones to our East which “block” the whole pattern from moving on.

      It is all hard enough and then the almighty decreed the Earth had to spin as well.

  7. Paul2 permalink
    December 29, 2015 10:36 pm

    The more things change and all that…….

    http://www.phenomena.org.uk/page29/page39/page39.html

  8. December 29, 2015 10:48 pm

    If it is down to the Sun, then this cold pool could be ready to grow and grow.

    http://www.nature.com/ncomms/2015/150915/ncomms9268/full/ncomms9268.html

  9. John F. Hultquist permalink
    December 30, 2015 5:51 am

    The jets are major “rivers of air” of global extent. These and other circulations are frequently described under the phrase “teleconnection pattern” — a recurring and persistent, large-scale pattern of pressure and circulation anomalies that spans vast geographical areas.
    http://www.cpc.ncep.noaa.gov/data/teledoc/teleintro.shtml

    The point is that changes over the UK/Europe ought to be reflected upstream, out over the north Atlantic and North America. So when you write:
    The Netweather forecast suggests that the jet stream will become much more zonal …” – it is reasonable to ask “What else is happening?”

    Here is a quote from a weather blog by a Seattle meteorologist after a vey wet and/or snowy December:
    But as the year ends, so does the rainy pattern. 2015 will end bone dry, and long range models suggest there will be little-to-no rain in the first two weeks of 2016. [Scott Sistek, KOMO News, 29 DEC 2015]
    Scott’s title is “Snoqualmie Pass has snowiest December on record; Seattle pretty rainy too” Link here.

  10. Vernon E permalink
    December 30, 2015 11:10 am

    Paul’s work and that of the commenters show just how much computation and science goes into large area weather analysis and forecasting. With all the tweaks the Met Office’s super computers have had to ensure that global warming is ever-present, have they been ruined for the sort of work that you guys are dealing with? Can they contribute to this science or has our money been thrown away?

  11. Rowland Pantling permalink
    December 30, 2015 3:24 pm

    Glad to see more emphasis on the jet stream which seems to dominate our weather. Next thing is can any credence be given to alleged geo-engineering as illustrated on geoengineeringwatch.org? i.e. is the spraying of chemicals, metals etc over various parts of the USA in particular as appears to be witnessed by ordinary folk artificially manipulating the position of the jet stream? I may be no scientist but our skies are often also almost obliterated by persistent “vapour” trails as well and I find it quite frightening. They look anything but natural to me.

    • nebakhet permalink
      December 30, 2015 4:30 pm

      Elevated co2 is having an increasing impact on temperatures and particle sources in the NH

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