Why does our weather come from the west

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Player of the Week. Submit Nomination for Player of the Week. Latest Newscasts. Investigate TV. Election Results. Gray DC Bureau. The reason that they most often move from west to east is due to the jet stream.

The jet stream is a narrow band of fast, flowing air currents located near the altitude of the tropopause that flow from west to east. The jet stream flows around the entire earth. They usually have a meandering, snake-like shape. Jet streams carry weather systems. Warmer tropical air blows toward the colder northern air.

These winds shift west to east due to the rotation of the earth. Every once in awhile, we get a backdoor cold front in the Mid-south. This is because an area of low pressure can pull down a cold front from the northeast to the southwest. The structure of low pressure systems, which move cold fronts, favors a front moving either north to south or northwest to southeast. The systems that move east to west are tropical systems due to the easterly trade winds. Thunder may occur at a cold front. This is the boundary between cold air and warm air and is when warm air replaces cold air at a point on the Earth's surface.

The presence of a warm front means warm air is moving in and rising up over cold air. This is because the warm air is 'lighter' or less dense, than the colder air.

So warm air is replacing cold air at the surface. The semi-circles on the front point to which direction the front is moving. As a warm front approaches, temperature and dew-point within the cold air gradually rise and pressure falls more quickly.

Precipitation usually occurs in a wide belt about km just ahead of the front. When the front has passed, the will be a steadying of the barometer pressure will stop falling , a jump in temperature and dew point, a change of wind direction, and precipitation will stop, or mostly stop. These are more complex than cold or warm fronts.

An occlusion is formed when a cold front catches up with a warm front. When a cold front catches up with a warm front, the warm air in the warm sector is forced up from the surface. Not all occlusions follow the same rules, as some will be more similar to warm fronts and some will be more like cold fronts, so some will cause it to feel warmer once it has passed, others cooler, some will lower the dew point, others will cause it to increase.

All occlusions will cause a rise in pressure, a change in wind direction and precipitation will slowly clear when they have passed. Weather can change on a daily basis especially at middle to high latitudes parts of the earth that are quite far north or south of the Equator where it is controlled by weather systems, depressions and anticyclones.

On a weather chart, lines joining places with equal sea-level pressures are called isobars. Charts showing isobars are useful because they identify features such as anticyclones areas of high pressure , depressions areas of low pressure , troughs and ridges which are associated with particular kinds of weather. Temperature affects other weather elements including air pressure, wind, cloud formation, humidity and precipitation. The movement of air around the earth from high pressure to low pressure is what brings about winds.

The direction given for the wind refers to the direction from which it comes. However, this is not true for all weather systems. Weather systems can really move in any direction. Often times tropical cyclones tropical depressions, tropical storms, and hurricanes travel from east to west. This is because tropical cyclones develop over warm sea waters and follow trade winds that blow westward. This is why hurricanes hit the east coast of the United States. Eventually, tropical systems can recurve and travel back eastward.

Note that weather movement from west to east occurs only in certain regions of the globe. It depends on where you are. Prevailing weather patterns refer to the movement of entire air masses, not just the winds they produce in their rotations. One air mass can blow in warm dry air today and cold wet air in hours, or tomorrow. Prevailing weather is the result of expansive convection currents formed by the temperature differences on the surface of the earth as latitude increases.

The Coriolis effect adds the twist.