Predicting weather

One way of predicting the weather is by looking at the clouds. To do this, you need to know that this is depending on changes in height and apperance on the clouds. There are five different type of clouds; stratus, cumulus, nimbus, cumulonimbius and cirrus.

Stratus clouds belong to the group low- level clouds, and appears from ground level up to 2500 meters. The stratus cloud looks like white/grey layer of sheets, and is composed of water droplets or ice crystals depending the temperature. The stratus cloud can cause fog, gentle rain or snow if it is cold enough.

Cumulus clouds usually appears less than 200 metres, and like the stratus, it is a low level cloud. In appearance they are often described as "puffy" or "cotton like". These clouds consists of mostly water droplets, but also ice crystals if cols enough.

Nimbus clouds can be found at an altitude around 2400 meters. They can look like grey-ish cotton balls, and these are loaded with heavy rain, snow or hail.

Cumulonimbius clouds are clouds associated with thunderstorms, and are capable of producing lightening, gusts, hail an even tornadoes. They are found on an altitude of 2000 to 16000 meters. The cumulonimbius cloud is often very tall and has a mushroom formed shape.

Cirrus clouds are considered high cloyds, and appears on an altitude higher than 5000 meters. The appearance is thin and wispy, and they are containg ice crystals.

Two important factors on weather are cold fronts and warm fronts. A warm front is a boundary between mass of warm air as it rises over a mass of cold air. A cold front is the opposite, a mass of cold air is moving and eventually replacing the mass of warm air. The weather is also depending on air pressure, either high or low. Air pressure is the force the atmosphere has/exerts on the Earth's surface. When cool air sinks, the pressure on the ground increases. When this happen, no clouds are formed or no vapour are condensed, because the air has warmed up as it reaches the ground. This means that there will be no rain, and the sky stays clear. However, when the warm air rises the pressure in the ground rises. This cause moisture condences to form clouds, which means rain will follow. This is beacuse the air cools as it rises.
 * In an area with high pressure, the weather will most likely occur as rain.
 * Even though Norway is in the polar region, it is relatively hot because of the low pressure. This eans that the air has time to warm up as it sinks
 * Compared to the East, the west coast of Norway is more rainy because of low pressure
 * Siberia is very cold, because the high pressure keeps clouds away which makes it easy for the heat to rise.