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A lady where I work showed me this 2 years ago. I think the persimmon seeds she brought were mostly spoons and knives. That winter was cooler than normal here, and there was some non-accumulating snow in early March.
Arctic Oscillation and Polar Vortex Analysis and Forecasts
October 7, 2016
Summary
• The Arctic Oscillation (AO) is currently strongly negative and is predicted to remain negative to strongly negative over the next two weeks. The AO is predicted to bottom out early next week and then slowly rise but still remain negative.
• The current negative AO is reflective of positive pressure/geopotential height anomalies in the Arctic especially on the North Pacific and European sides of the Arctic and negative pressure/geopotential height anomalies across the mid-latitudes of the Northern Hemisphere (NH). And because the anomalies are strongly positive on the North Atlantic side of the Arctic near Iceland, the North Atlantic Oscillation (NAO) is currently also negative and is predicted to remain negative for the next two weeks.
• With pressure/geopotential height anomalies predicted to remain positive across much of the Arctic and pressure/geopotential height anomalies predicted to remain negative across the NH mid-latitudes, the AO/NAO are likely to remain in negative territory into the foreseeable future.
• With the AO/NAO firmly negative for the remainder of the next two weeks, favors below normal temperatures across large portions of northern Eurasia including Europe, East Asia and eastern North America. However because North America will be an exception to the remainder of the NH mid-latitudes, with mostly positive pressure/geopotential height anomalies, temperatures will average above normal much of next week. The following week the low heights in the North Atlantic may retrograde westward into eastern North America and finally cause temperatures to cool.
• Both low sea ice and the negative AO are favorable for the rapid advance of Siberian snow cover. Eurasian snow cover is above normal and this trend should continue through at least mid-month. High Eurasian snow cover and low Arctic sea ice in the Barents-Kara seas favor first, a strengthening Siberian high and then a weakened polar vortex in winter.
• The polar vortex both in the stratosphere and the troposphere are unusually weak so far this fall, if this trend continues severe winter weather is likely for widespread portions of northern Eurasia, including Europe and East Asia, and the eastern United States (US).
Impacts
In previous blogs I noted the unusually negative AO in the stratosphere and that the strong positive polar cap height anomalies look to be descending down into the troposphere. The weak stratospheric polar vortex has now been followed by an unusually weak tropospheric polar vortex and a deeply negative tropospheric AO. This is not the time of year when tropospheric-stratospheric coupling is considered active but the most recent polar cap height anomaly (PCH) plot is certainly suggestive of a downward propagation of warm/positive PCH from the stratosphere to the troposphere. Regardless, the tropospheric AO is strongly negative, which favors widespread cold temperatures across the NH mid-latitudes, especially northern Eurasia and a rapid advance in snow cover especially Siberia and to a lesser extent Canada. October Eurasian snow cover extent is a key predictor in our winter forecast and if our expectations are correct that Eurasian snow cover will be above normal for the month of October, this will bias our model colder for the winter forecast.
As I have discussed in previous blogs, the Arctic sea ice is well below normal and possibly most importantly for longer term weather sea ice is below normal in the Barents-Kara seas. This will also bias the winter forecast colder. Also with the likelihood that the AO will be strongly negative right through the middle of October, October 2016 will probably rival other recent Octobers for the most negative October AO observed, which include October 2002 and 2009. And though there is not a strong relationship between the October AO and the winter AO, the winter AO in 2002/03 and 2009/10 were both negative and cold temperatures were widespread both across northern Eurasia and the Eastern US. However the AO was much more negative in the latter winter and the evolution of the polar vortex was quite different. It is still very early and the outcome of this winter still very much in doubt but in my opinion, the longer that the tropospheric and/or stratospheric polar vortex remain weak and the AO negative, favors a colder winter solution.
In the near term the NH atmospheric circulation looks stable over the next two weeks. With the AO/NAO solidly negative, positive geopotential height anomalies will dominate the Arctic while negative geopotential height anomalies will be widespread across the mid-latitudes including both the North Atlantic and the North Pacific. A negative AO most strongly favors below normal temperatures across northern Eurasia especially Siberia. And because the NAO is also predicted to be strongly negative, below normal temperatures are also favored across Europe. However because the Aleutian low will be anomalously deep especially to the southeast of its climatological position this will force above normal geopotential heights across much of North America and the overall warm temperature pattern will likely continue for much of North America at least through next week. However the longer that the AO/NAO persists negative does eventually favor lowering heights in the Eastern US with a concomitant drop in temperatures, which is predicted for week two.
Yes, models right now are showing either normal or above normal winter. JAMSTEC showing torch. However, weak La Nina/cool neutral ENSO doesn't usually create such conditions
Whether winter ends up above or below normal, please, I repeat....please, don't linger into March and April. I'm so sick of that.
I would normally agree with you, (I do like Spring) but given that this Summer was torture for me, my batteries will need a long time charge which means I need winter to last into May and then a Spring like Summer. lol
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