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sebastiaan1973

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About sebastiaan1973

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  1. @Gael, seems to me as a delay. http://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/ -> Weak La nina. GLOSEA5 shows a positive NAO-phase, similiar of the declining phase of solar activity. I need that hat!
  2. Winter 2017. LIkely a weak La Nina, Solar activity in the declining phase. Which resembles a positive NAO phase and QBO in it's easterly phase (right now it is still westerly -> http://www.esrl.noaa.gov/psd/data/correlation/qbo.data)
  3. In my opinion we are in the declining phase. Which resembles a positive NAO phase.
  4. Well we are still in the declining phase. http://cc.oulu.fi/~kmursula/publications/Maliniemi_etal_JGR_2014.pdf -> temperatures. However, the clearest pattern of the temperature anomalies is not found during sunspot maximum or minimum, but during the declining phase, when the temperature pattern closely resembles the pattern found during positive NAO. Moreover, we find the same pattern during the low sunspot activity cycles of 100 years ago, suggesting that the pattern is largely independent of the overall level of solar activity. So i.m.o. nothing interesting in terms of solar activity coming winter.
  5. Hi Nouska, what's opinion. Is the winter of 2017 still in the 'declining phase'?
  6. Well I think his comment is in line with Finnish research. However, the clearest pattern of the temperature anomalies is not found during sunspot maximum or minimum, but during the declining phase, when the temperature pattern closely resembles the pattern found during positive NAO. Moreover, we find the same pattern during the low sunspot activity cycles of 100 years ago, suggesting that the pattern is largely independent of the overall level of solar activity. http://onlinelibrary.wiley.com/doi/10.1002/2013JD021343/abstract
  7. Sorry to say, but I think the early SSW won't be accomplished. Perhaps later on?
  8. http://iopscience.iop.org/article/10.1088/1748-9326/10/10/104007/pdf Some research. There has been a great deal of recent interest in producing weather forecasts on the 2–6 week sub-seasonal timescale, which bridges the gap between medium-range (0–10 day) and seasonal (3–6 month) forecasts. While much of this interest is focused on the potential applications of skilful forecasts on the sub-seasonal range, understanding the potential sources of sub-seasonal forecast skill is a challenging and interesting problem, particularly because of the likely state-dependence of this skill (Hudson et al 2011). One such potential source of state-dependent skill for the Northern Hemisphere in winter is the occurrence of stratospheric sudden warming (SSW) events (Sigmond et al 2013). Here we show, by analysing a set of sub-seasonal hindcasts, that there is enhanced predictability of surface circulation not only when the stratospheric vortex is anomalously weak following SSWs but also when the vortex is extremely strong. Sub-seasonal forecasts initialized during strong vortex events are able to successfully capture the associated surface temperature and circulation anomalies. This results in an enhancement of Northern annular mode forecast skill compared to forecasts initialized during the cases when the stratospheric state is close to climatology. We demonstrate that the enhancement of skill for forecasts initialized during periods of strong vortex conditions is comparable to that achieved for forecasts initialized during weak events. This result indicates that additional confidence can be placed in sub-seasonal forecasts when the stratospheric polar vortex is significantly disturbed from its normal state.
  9. I spoke today to someone of MeteoGroep (group) Netherlands. They expect a warm januar and possibilities in februar for cold weather. In their opinion the chance for a minor SSW is high.
  10. The AO is currently positive and is predicted to trend negative but still remain near neutral. 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. Though the models are not predicting necessarily cold weather it should result in damping of the large positive temperature anomalies for Europe, western Asia and the Eastern United States. However the models predict low pressure/geopotential heights to continue on the North Pacific side of the Arctic. This will likely result in any cold weather being focused in Western North America for much of the remainder of December. Models are predicting an increase in energy transfer from the troposphere to the stratosphere starting the third week of December. This will likely lead to perturbation of the polar vortex during the latter half of December. The more the vortex is perturbed, the higher our confidence in a cold second half of winter. Longer-term high latitude boundary conditions favor a negative bias to the AO including extensive Eurasian snow cover and low sea ice extent in the Barents-Kara seas. The key will be how strong the energy transfer from the troposphere to the stratosphere is in late December and how much the polar vortex is perturbed. If the energy transfer does not significantly weaken the polar vortex, the AO will likely remain mostly positive and mild temperatures will dominate the mid-latitudes. The duration and amplitude of the atmospheric energy transfer or WAFz is likely to be critical for the weather during the middle and later parts of winter. We continue to anticipate the active transfer of energy from the troposphere to the stratosphere and a weakening of the polar vortex starting in December and continuing into January. Following the weakened polar vortex we would further expect a negative AO and cold temperatures across the Northern Hemisphere continents. However if the active WAFz does not persist and/or strengthen in amplitude then the polar vortex will recover and remain strong, and it becomes increasingly likely that the stratosphere and troposphere will couple in a way that favors a positive AO with mild to even very mild temperatures across the Northern Hemisphere mid-latitude continents. http://www.aer.com/science-research/climate-weather/arctic-oscillation
  11. Recretos aka Mr Angerfist Didn't know this kind of music was popular in eastern Europe. Something else.. http://onlinelibrary.wiley.com/doi/10.1002/2014JD022022/full Abstract It has been suggested that the Sun may evolve into a period of lower activity over the 21st century. This study examines the potential climate impacts of the onset of an extreme “Maunder Minimum-like” grand solar minimum using a comprehensive global climate model. Over the second half of the 21st century, the scenario assumes a decrease in total solar irradiance of 0.12% compared to a reference Representative Concentration Pathway 8.5 experiment. The decrease in solar irradiance cools the stratopause (∼1 hPa) in the annual and global mean by 1.2 K. The impact on global mean near-surface temperature is small (∼−0.1 K), but larger changes in regional climate occur during the stratospheric dynamically active seasons. In Northern Hemisphere wintertime, there is a weakening of the stratospheric westerly jet by up to ∼3–4 m s−1, with the largest changes occurring in January–February. This is accompanied by a deepening of the Aleutian Low at the surface and an increase in blocking over Northern Europe and the North Pacific. There is also an equatorward shift in the Southern Hemisphere midlatitude eddy-driven jet in austral spring. The occurrence of an amplified regional response during winter and spring suggests a contribution from a top-down pathway for solar-climate coupling; this is tested using an experiment in which ultraviolet (200–320 nm) radiation is decreased in isolation of other changes. The results show that a large decline in solar activity over the 21st century could have important impacts on the stratosphere and regional surface climate.
  12. Thanks a lot for this piece of work. I placed a link at weerwoord.be, so the Dutch & Belgium weatherlovers can enjoy your forecast as well.
  13. Of course we see some wave activity, but temperature wise we are still & in the forecast under the normal temperature.
  14. HI Chio, did you read this forecast? http://www.americanwx.com/bb/index.php/topic/47251-my-winter-outlook-2015-16/
  15. SIberian high http://www.americanwx.com/bb/index.php/topic/47140-griteaters-winter-outlook-15-16/?p=3737459 yet another winter forecast.