De OPI is gemaakt door een aantal Italianen. Er is nog steeds geen artikel verschenen met hun methodiek, het kan dus ook niet gecheckt worden wat ze nu precies doen. De OPI kwam uit op -2.12, de op 1 na laagste score.
Dit jaar is er een duidelijk blok voor stevig negatieve AO; SAI en OPI vs de modellen die met zacht winterweer komen. Spannend!
Basing on the above mentioned correlation, such a low OPI Index value suggests a strongly negative three months mean winter AO, leading to a very unsettled winter Tropospheric Polar Vortex and frequent descent of the Polar Jet over the mid latitudes (negative geopotential anomaly). A colder and perturbed winter over northern hemisphere continents is forecasted, especially for mid latitudes areas. Europe should be affected by a large area of lower than usual geopotential heights. Moreover, performed hindcasts show that very negative AO winters are generally colder especially over United Kingdom, Netherlands, France and Germany.
As mentioned in our introduction, the single OPI factors analysis allows to be more specific. In particular one can note how the mean value of the position of axis of the vortex is quite high (f? 25°), perpendicular to the imaginary line connecting the two main oceans (Pacific and Atlantic, together with a positive GPH anomaly (500 hPa) over the Arctic (Kara-Barents sea). These factors suggest, during periods of maximum wave activity, some winter dynamics with simultaneous main planetary waves activity, tending to split the Tropospheric Polar Vortex, along an axis more or less similar to that observed during October. Periods following such a dynamic would be characterized by a low or negative zonal index, with rotation of the axis and pronounced wave activity over the Atlantic Ocean. This would push cold arctic/continental arctic air masses toward Europe. Specifically over Europe, our OPI evolution and October pattern analysis, suggest that the first cold anti-zonal period should arrive with good probability in early winter, followed by the onset of a stronger Polar Jet over the North Atlantic and a milder but more unsettled period. This period with higher zonality should be interrupted by a new increasing of the wave activity over the North Atlantic, with a renewed colder pattern; differently from the first period, this second colder period could be characterized by a lower anti-zonality, with higher probabilities for arctic air masses to reach lower latitudes.
Meer lezen: http://app.til.it/opi/
& op netweather https://forum.netweather.tv/topic/81494-october-pattern-index-opi-monitoring-winter-season-2014-2015/page-64
Dit jaar is er een duidelijk blok voor stevig negatieve AO; SAI en OPI vs de modellen die met zacht winterweer komen. Spannend!
Basing on the above mentioned correlation, such a low OPI Index value suggests a strongly negative three months mean winter AO, leading to a very unsettled winter Tropospheric Polar Vortex and frequent descent of the Polar Jet over the mid latitudes (negative geopotential anomaly). A colder and perturbed winter over northern hemisphere continents is forecasted, especially for mid latitudes areas. Europe should be affected by a large area of lower than usual geopotential heights. Moreover, performed hindcasts show that very negative AO winters are generally colder especially over United Kingdom, Netherlands, France and Germany.
As mentioned in our introduction, the single OPI factors analysis allows to be more specific. In particular one can note how the mean value of the position of axis of the vortex is quite high (f? 25°), perpendicular to the imaginary line connecting the two main oceans (Pacific and Atlantic, together with a positive GPH anomaly (500 hPa) over the Arctic (Kara-Barents sea). These factors suggest, during periods of maximum wave activity, some winter dynamics with simultaneous main planetary waves activity, tending to split the Tropospheric Polar Vortex, along an axis more or less similar to that observed during October. Periods following such a dynamic would be characterized by a low or negative zonal index, with rotation of the axis and pronounced wave activity over the Atlantic Ocean. This would push cold arctic/continental arctic air masses toward Europe. Specifically over Europe, our OPI evolution and October pattern analysis, suggest that the first cold anti-zonal period should arrive with good probability in early winter, followed by the onset of a stronger Polar Jet over the North Atlantic and a milder but more unsettled period. This period with higher zonality should be interrupted by a new increasing of the wave activity over the North Atlantic, with a renewed colder pattern; differently from the first period, this second colder period could be characterized by a lower anti-zonality, with higher probabilities for arctic air masses to reach lower latitudes.
Meer lezen: http://app.til.it/opi/
& op netweather https://forum.netweather.tv/topic/81494-october-pattern-index-opi-monitoring-winter-season-2014-2015/page-64
„Et nul ne se connait tant qu'il n'a pas souffert, „C'est une dure loi, mais une loi suprème, „Vieille comme le monde et la fatalité, „Qu'l nous faut du malheur regevoir le baptéme, ~Et qu'a ce triste prix tout doit étre acheté. „Les moissons pour murir out besoin de rosée, „Pour vivre et pour sentir l'homme a besoin de pleura, „La joie a pour symbole une plante brisée, „Humide encore de pluie et couverte de fleurs."