Northwest Cold

Calling itself Atlantic Polar Front to the surface of thermal discontinuity that moves away to the circumpolar winds from hottest West and Southwest of originary of the center of action, of directions Northeast and Northwest. This front that if distende, in the South America, since the Chaco until the Gergia island cutting the coast in the River of the Silver. The intense renewal of the cold anticyclone hinders the Atlantic Polar Front in direction to the equator, penetrating in wedge, under hot tropical air. Soon the ascension of this, results in strong clouds, rains and conditions of icing and thunderstorms in the period frontal, following itself in cold and dry time, that many times precedes the intense waves of cold, under High the posterior one of temperature. According to BLACKSMITH, on the system frontal of the winds it alleges. The severe thunderstorms are frequently associates the lines of organized convergences as the cold fronts, hot and oclusas. Its development is common, over all, throughout the cold fronts associates to a extratropical cyclone. The convergence of the surface winds occurs, in general, throughout these fronts.

The winds in the advantage of the cold front blow normally in the South hemisphere of NE and, of the rear, sw. This results in a convergence of air throughout the front, forcing the ascent of hot air. (BLACKSMITH, 2006.p.113) With the increase of the Atlantic Polar Front in the center of action of the Atlantic that is dragged for lower latitudes, that is, it returns and it goes being amortized, for after that being revigorated by the proper polar anticyclone when the Atlantic Polar Front if dissolves in the tropic, under a general heating. No longer period that in them worries summer and autumn, more accurately of January the March, the progressos of the Atlantic Polar Front are to a great extent weak, not reaching to exceed the tropic.