Arctic High Appears Early, Could Bring Extreme Weather Around the World Soon

<p style=";text-align:left;direction:ltr">Arab Weather - We, the weather forecast team at &quot;Arab Weather&quot;, are still following the latest developments in the polar vortex, which the latest weather data still indicate is weak in the upper layers of the atmosphere, which has begun to be completely reflected in the lower layers of the atmosphere, represented by the formation of an area of high atmospheric pressure over important areas in the North Pole.</p><p style=";text-align:left;direction:ltr"><br /><br /></p><p style=";text-align:left;direction:ltr"> Weather forecasters at Arab Weather said that a strong polar vortex means a strong polar circulation, which usually traps cold air in the polar regions, leading to milder weather conditions in most parts of the United States and Europe. In contrast, a weak polar vortex causes the polar jet stream to break free and become difficult to contain, meaning it rushes from the polar regions to the United States and Europe, and perhaps to lower latitudes in some cases.</p><p style=";text-align:left;direction:ltr"></p><p style=";text-align:left;direction:ltr"></p><h3 style=";text-align:left;direction:ltr"> <strong>What does a temporary warming of the polar vortex mean?</strong></h3><p style=";text-align:left;direction:ltr"></p><p style=";text-align:left;direction:ltr"> Normally, if we want to see strong stratospheric warming, the temperature and pressure in the stratosphere must rise significantly, causing the polar circulation above to collapse. Continuing this process leads to the transfer of energy from the upper atmosphere to the lower layers, which may create high surface air pressure around the Arctic Circle, as current weather maps indicate, and thus the very cold air masses move away from the Arctic Circle and descend below the high pressure.</p><p style=";text-align:left;direction:ltr"><br /> See also:</p><p style=";text-align:left;direction:ltr"> <a href="https://www.arabiaweather.com/ar/content/%D8%AF%D8%B1%D8%A7%D8%B3%D8%A9-... study: The development of the La Niña phenomenon and its association with the collapse of the stratospheric polar vortex during the winter</strong></a></p><p style=";text-align:left;direction:ltr"></p><p style=";text-align:left;direction:ltr"> Studies indicate that the weakness of the polar vortex may often lead to the expansion of the polar jet stream to large parts of the European continent, especially its center and west, which leads to significant cold weather, waves of snow, and extreme weather conditions at times. The following map from the European Center shows the rise in temperatures in the upper stratosphere, the weakness of the polar jet stream, and its decline to the middle latitudes in the coming period: </p><p style=";text-align:left;direction:ltr"><img alt="" src="/sites/default/files/uploads-2020/ecmwf-deterministic-nhemi-t50_anom-7892000.png" style="width: 984px; height: 808px;" /></p><p style=";text-align:left;direction:ltr"><img alt="" src="/sites/default/files/uploads-2020/ecmwf-deterministic-nhemi-z200_speed-8032400.png" style="width: 984px; height: 808px;" /><br /><br /></p><p style=";text-align:left;direction:ltr"> Weather forecasters at Arab Weather said that in response to this process, significant changes will occur in the coming period and during the first third of October in the weather conditions in several regions around the world, represented by the rush of very cold polar basins towards eastern America and western Europe, in addition to very cold weather in the regions of northern Europe and Russia, which increases the possibility of heavy rains, extreme cases and snowfall in those regions. It is expected that the central Mediterranean regions will benefit from these weather systems by increasing rainfall in several regions of North Africa amid early cold weather. The following map shows the distribution of cold air masses in the 500 hectopascal layer in the coming period, as we notice the decline of polar air masses below the high air pressure that will form over the North Pole: </p><p style=";text-align:left;direction:ltr"><img alt="" src="/sites/default/files/uploads-2020/ecmwf-deterministic-nhemi-z500_anom-8302400.png" style="width: 984px; height: 808px;" /></p><p style=";text-align:left;direction:ltr"></p>