Much of the central, northern and eastern US and Canada is in the grip of a deep freeze, experiencing the coldest temperatures in decades, due to a deep polar upper low. WeatherTheatre SceneOne gives a 3D perspective of the evolution and progression of this winter storm, also called a ‘polar vortex’.
WeatherTheatre SceneOne 3-1-2014-12z, North America, Top Down View. An upper shortwave trough, indicated by the sharp u-shaped curvature in the jetstream along the tropopause surface in the right half of the image, shows the first wave of cold air to affect the central-eastern US. At this time, the cold air was peaking over the northeast US. Red shadings indicate the strongest winds on the tropopause while blue shadings the lightest. The 300K Theta surface partially obscures the tropopause near the top of the image, where its height is greater. The blue shading is indicative of the cold polar air mass in this region.
WeatherTheatre SceneOne 6-1-2014-00z, North America, Top Down View. The large u-shaped valley in the tropopause represents the second wave of cold air to affect the US, longer in wavelength than the initial cold snap, and responsible for the coldest temperatures in decades. The red shadings indicate the strongest winds, associated with the jetstream. The dark blue shadings near the top indicate cold temperatures of the 300K Theta surface, which is overlapping and obscuring the tropopause.
The icy storm complex began shortly after New Year, 2014, with a shortwave upper trough sweeping over central-eastern states. This was then followed by a longer-wave trough associated with the ‘polar vortex’, bringing frigid conditions across much of the US. The only areas to escape were along the west coast and the far south.
WeatherTheatre SceneOne 3-1-2014-12z, North America, Westerly Vertical View of the first cold wave, showing a deep tropopause (upper surface) fold along the wave front, shaded red due to the intense winds associated with the jetstream in this region.
WeatherTheatre SceneOne 3-1-2014-12z, North America, Northeasterly Vertical View, looking along the axis of the shortwave trough responsible for the first frigid weather across central-eastern states. Red shadings correlate with the strongest winds (upper surface) and warmest temperatures (lower surface). Conversely, blue shadings correlate with the weakest winds (upper surface) and coldest temperatures (lower surface).
WeatherTheatre SceneOne 7-1-2014-00z, North America, Top Down View. The second and longer wavelength upper trough responsible for the coldest temperatures in decades is seen in the u-shaped tropopause valley. The red shadings indicate intense jetstream winds. The blue shaded 300K Theta surface obscures the tropopause in the valley region.