Basic Weather Terms Lesson Part 1
Important things to know when it comes to weather are the terms that a meteorologist uses on the television, radio or on a weather website. The first term is Return flow. Sometimes you will hear a meteorologist use this term. The best way to understand this is to look at a weather map. When you see a High pressure center which is the blue H, look to the western side of that high pressure. This is where the warm moist air starts moving from the south back towards the north, which is why it is called return flow.
A second term used in our weather world is Zonal. Sometimes you will hear the television meteorologist talk about the jet stream chart. This chart has animated arrows moving mostly west to east. The flow known as zonal is when the Jet stream is traveling from west to east in almost a straight line. For example, if we see the Jet stream is moving from Seattle Washington in a straight line all the way across to North Dakota, this is known as zonal flow. The air in a zonal flow weather system tends to move faster and is usually less intense.
The third term is known as meridional flow. This is also seen on the jet stream map. This happens when the line is moving from North to the South. This type of weather pattern is very important to a meteorologist because with this type of flow the weather systems move much slower and have the chance to get stronger and create more damage. When we have major tornado outbreaks this type of flow is present in the area of the storms. An example would be the line going from North Dakota all the way south into Oklahoma.