What is the best interactive real-time weather map online?

What is a weather map?How do we read a weather map?

• Please i really really need to know this... Please give as much information as you can find. Thankyou!

• Answer:

  How to Read a Weather Map Weather maps provide a simplified depiction of the current or predicted weather conditions of an area. They can be based on satellite and radar images, recordings from instruments at weather stations, and computer analyses. The most common weather map you'll come across is a surface analysis, shown here. As they appear on television, in a newspaper or on a website, a surface analysis may seem like mere tangles of strings and circles cast out over a map to the average person. However, once you learn to interpret the symbols and lines in a weather map, you won't need a meteorologist to tell you what you're looking at. Steps 1.Understand general concepts of the weather. What most people are concerned with is precipitation which, in meteorology (the study of weather), is any form of water that falls to the Earth's surface. Forms of precipitation include rain, hail, snow or dew. Generally, high pressure implies fair weather and low pressure is usually associated with precipitation. 2.Find a weather map. Watch out for one on the TV news, find maps online or look in your local newspaper. Other sources may include magazines and books. Newspapers are a convenient method to find a weather map, as it is cheap, reliable and content is able to be cut out so you can analyze it while you're learning to interpret the symbols. 3.Look at the map. The type may be dependent on what sort of map you chose and from where. If the map is stationed over a smaller area, this may be easier to interpret. Focusing on a larger scale may be difficult for the beginner. On the map, notice the location, lines, arrows, patterns, colors and numbers. Every sign counts, and all are different. 4.Examine the distribution of pressure systems. Air pressure is the 'weight' or pressure the air exerts on the ground, measured in millibars. -Check for isobars (iso = equal, bar = pressure), or plain, curved lines that indicate areas of equal air pressure. Isobars play a major role in determining the speed and direction of wind. When the isobars form concentric closed (but not always round) circles, the smallest circle in the center indicates a pressure center, indicating a high pressure system (depicted by an "H" in English, "A" in Spanish) or a low pressure system (depicted by an "L" in English, "B" in Spanish). Air moves from a high pressure area to a low pressure area, thus creating wind. The closer the isobars, the stronger the winds. -Pressure systems are associated with certain weather patterns. *Cyclone (low pressure system): Increased cloudiness, winds, temperatures, and chance of precipitation. Represented on a weather map by isobars that are very close together, arrows traveling clockwise (Southern Hemisphere) or anticlockwise (Northern Hemisphere), usually with a "T" in the middle isobar, which forms a round circle (the letter can vary, however, depending on the language the weather report is presented in). It can also be shown through radar imagery. Tropical cyclones (South Pacific) are also named hurricanes around America or typhoons in coastal Asia. *Depression (extratropical cyclone): Low pressure system that occurs outside of the tropics. Same characteristics as a cyclone. *Anticyclone (high pressure system): Indicates clear, calm conditions with reduced chance of precipitation. Drier air usually results in a greater range of high and low temperatures. Represented on a weather map as isobars with an "H" in the middle isobar and arrows showing which direction the wind is flowing (clockwise in Northern Hemisphere, anticlockwise in the Southern Hemisphere). Like cyclones, they can also be shown with radar imagery. 5.Observe the type and movement of fronts. These mark the boundary between warmer air on one side and colder air on the other. If you are close to a front and you know the front is moving towards you, you can expect a change in weather (e.g. cloud formation, precipitation, thunderstorms, and wind) when the front boundary passes over you. Their path can be distorted by mountains and large bodies of water. On a weather map, you will notice some lines that have semi-circles or triangles on either side, or both (shown here). Tese indicate the boundaries for various types of fronts: *Cold front: Rainfall can be torrential and wind speeds can be high. Represented on a weather map as a (blue) line with triangles bordering one side. The direction that the triangles point is the direction in which the cold front is moving. *Warm front: Often brings a gradual increase in rainfall as the front approaches, followed by prompt clearing and warming after the front passes. If the warm air mass is unstable, the weather might be characterized by prolonged thunderstorms. Represented on a weather map by (red) lines with semi-circles on one side. The side that the semi-circles are on represent the direction in which the warm front is heading. *Occluded front: Formed when a cold front overtakes a warm front. Associated with a variety of weather events (possibly thunderstorms) depending on whether it is a warm or cold occlusion. The passing of an occluded front usually brings drier air (lowered dew point). Represented on a weather map by a line with semi-circles and triangles both on the same side. Whichever side they're on is the direction the occluded front is going in. *Stationary front: Indicates a non-moving boundary between two different air masses. Long continuous rainy periods that linger for extended periods of time in one area and move in waves. Represented on a weather map by a line with semi-circles bordering one side and triangles along the opposite side, indicating that the front is not moving in any direction. 6. If your weather map has station models, each one will plot the temperature, dewpoint, wind, sea level pressure, pressure tendency, and ongoing weather with a series of symbols. • Generally, temperature is recorded in Celsius degrees and rainfall is measured in millimeters. In the US, temperatures are in Fahrenheit and rainfall is measured in inches. • Cloud cover is indicated by the circle in the middle; the extent to which it's filled indicates the degree to which the sky is overcast. • Wind barbs point in the direction of the wind. Lines or triangles coming off the the main line at an angle indicate wind strength: 50 knots for every triangle, 10 knots for every full line, 5 knots for every half line.