The typical weather map will provide the average person with a simplified version of the current or forecasted weather condition of a specific area. Most users would have at some time or the other been exposed to what is commonly referred to as a surface analysis.
Most weather enthusiasts find themselves greatly concerned with precipitation or simply known as the study of weather conditions relative to meteorology which includes any form of water which falls to the surface of the Earth. Precipitation will occur in several forms such as hail, rain, snow, and even sleet. The existence of high pressure generally signifies the possibility of fair to fine weather as opposed to low pressure which normally implies heavy precipitation.
Most people will find themselves glued to their local television stations or online source to access a current weather map. However these sources are not always reliable and often may not contain an updated version of the desired location you might be interested in. Most weather forecasters have suggested that the local newspaper is an adequate and more reliable source when looking for an updated weather map.
Finding a map with a smaller coverage area is always a great place to start to hone your skills as a future weather forecaster as they are quite easier to interpret. Close attention should be given to the specific locations, lines, patterns, colors, arrows and even number sequences as each sign and symbol carries with it some meaning of significance.
Air pressure is easily described as the current weight or pressure the air will exert on the surface measured in millibars. Pressure within the atmosphere plays a vital role with regards to specific weather patterns. Most maps will display current air pressure in what is known as isobars which can be observed as plain, curved lines indicating existing air pressure of an equal value.
Air speeds and wind direction is determined by these isobars as. Isobars are seen to form concentric closed circles circular or otherwise which will be depicted by the smallest circle in the center to reflect the central pressure point. Such a pressure centre can be either High and will be marked by the letter H or low and in that case marked with a letter L.
Surrounding air within a pressure system does not flow in a downward direction but rather will tend to flow around the system due to what has been known as the Coriolis Effect or the Rotation of the Earth. Isobars seen as in close proximity teach other will imply the existence of strong winds.
Cloud intensity, wind speeds and temperature increase are all signs of a Low Pressure System and a higher chance of precipitation. This system is represented on the current weather map by closely positioned isobars. Arrows noticeably signify a clockwise direction or Southern Hemisphere or Northerly Hemisphere direction seen a anti-clockwise will typically be marked with a T in the center isobar forming the round circle. Specific radars through their imagery capability will identify specific low pressure systems thus warning of potential risks of hurricanes and tropical cyclones.
Calm clear conditions with the unlikely possibility of precipitation is known as a High Pressure System which can be easily identified on the weather map by isobars with an H in the middle circle with arrows pointing in the direction showing wind currents. These systems are also easily identifiable by radar imagery.
Cold fronts are normally identified by blue lines with specific triangles pointing in the direction of motion, with the warm fronts seen as red lines with semi-circles on one side. The positioning of the semi-circles will indicate the direction the warm front is heading.
An Occluded front forms when a cold front overtakes a warm front and will generally indicate the possibility of strong thunderstorms and are seen on the weather map as purple lines with both semi-circles and triangles as seen in both the warm and cold fronts indicating the specific side of each related front.
The stationery front is seen as the motionless boundary between two existing masses of air and is marked by a semi-circle bordering one particular side and triangles on the opposite side as an indication that the front is not moving. Conditions associated with stationary fronts are seen as continuous periods of rainy weather for lengthy periods of time.
Weather maps containing station models indicating observation points will contain specific readings plotting dew-points, temperature, sea levels and pressure conditions with a range of symbols.