Weather Stations & Weather Map Symbols

Transcription

1 Weather Stations & Weather Map Symbols

2 Weather Maps Almost everyone wants to know what the weather will be for the day, or even the week. There are people who live in a region where the weather changes very little; people who live in the tropics know it s going to be hot all the time and people who live near one of Earth s polar regions know it is going to be cold most of the time. But, even these regions have weather differences, and everyone is affected by the weather. Being able to look at a weather map and know what it may do for the day and also for the week ahead is

3 Weather Maps A weather map is an indispensable tool to a meteorologist. They use it to compile and illustrate weather data that has been collected from observation stations. Weather maps include data for temperature, cloud type and cover, air pressure, precipitation, and wind speed and direction. Weather maps use various symbols to represent the weather. For instance, fronts are drawn as heavy lines and isobars are drawn with thin lines.

4 Understanding Weather Symbols The purpose of a weather map is to give a graphical or pictorial image of weather to a meteorologist. As a forecasting tool, weather maps allow meteorologists to see what is happening in the atmosphere at virtually any location on earth. Complex three-dimensional models of weather systems can be made by collecting weather data at multiple levels in the atmosphere. Computers then compile that information to produce the pictures that weather scientists analyze. In the early days of meteorology, these pictures were hand drawn!

5 Understanding Weather Symbols

6 Understanding Weather Symbols There is not enough room on a weather map to include all of the weather details in full text so meteorologists use symbols to represent current weather conditions.

7 Symbols used in plotting report

8 Frontal Systems Weather fronts are the boundaries between air masses with different characteristics such as temperature, humidity, and air pressure. An air mass is a large parcel of air with roughly the same temperature, humidity, or pressure throughout. Different air masses tend not to mix. The clashing of two or more air masses is what causes severe storms. The front is literally the front end of an air mass. Movement of a front will depend largely on the conditions inside the air mass. Air masses tend to be either moist or dry in humidity content. Temperatures are either cold (polar) or warm (tropical).

9 Can you name each of the fronts pictured here? 3. Stationary front 5. Trough 7. Dry Line 1. Cold front 8. Tropical Wave 2. Warm front 4. Occluded front 6. Squall Note: The symbols point in the direction that the front is moving towards

10 The symbols used for cloud species Aviation is one area where understanding cloud types can help a plane to have a smoother flight. Clouds give pilots an indication of air motion, stability and moisture. These cloud types are reported using universal symbols that all aviators can understand. Often, the cloud symbols are also used on weather maps which were all learned in your cloud book!

11 Cloud Cover in a Weather Station Model Weather Stations often report weather in a station model. The central part of a station model is the cloud cover. The amount of cloudiness reported to you during the evening news is indicated by a series of symbols.

12 The Symbols Used For Cloud Species

13 Precipitation Weather Map Symbols Used by Meteorologists When reporting rain to a local area, meteorologists need a universal way to indicate the conditions they observe. The weather map symbols for rain, snow, sleet, hail, and more can be seen in the diagram. These often do not show up on your evening news, but a meteorologist will use these to communicate the information

14 Radar Intensity Colors on a Weather Map Radar Echo Intensity shows the amount of precipitation in an area by assigned a series of colors to indicate heavy or light precipitation including hail, rain, and snow. Radar intensity is a way to see through rain. A pulse of energy is beamed through a cloud and the amount of echo returned will give the intensity of precipitation. The echo is actually a reflection of the energy and a computer ill generate a color code to indicate the amount of precipitation.

15 Radar Intensity Colors on a Weather Map The DBZ on the image is Decibels When the radar echo reaches the precipitation, the larger the raindrops, or the more raindrops there are, the greater the DBZ value and the heavier the precipitation.

16 Isobars: connect areas with equal air pressure. The distance between the isobars is called the pressure gradient The closer the isobar lines, the greater the change in air pressure, and the greater/faster the winds speeds. High pressure systems bring clear/sunny weather and wind flows out and clockwise (right) Low pressure systems bring overcast/stormy weather and wind flows in and counter- clockwise (left)

17 Wind Barbs Wind barbs show wind directions and speed in knots The wind barb points in the direction it is coming FROM. To get the wind direction, all you have to do it imagine a compass placed right over the top of the wind diagram or station model and it will point to the wind direction.

18 Wind Barbs Wind barbs indicate wind speed and direction on weather station models. Wind barbs are used to show wind intensity with a series of small pennants (flags). A full blacked pennant or triangle is 50 knots of speed A full line of the wind barb is 10 knots of speed A half line is 5 knots of speed ****1 knot = miles per hour

19 Wind Barbs The information for wind speed is always given in knots. All you have to do is add up the numbers on the wind barb and you get the wind speed. To get the wind direction, all you have to do it imagine a compass placed right over the top of the wind diagram or station model and it will point to the wind direction.

20 Weather Station Model Television weather reports represent weather conditions with smiling suns, rainy clouds and flashing bolts of lightning. In studying the weather we need to know where it is raining and where it is sunny, the wind speed and direction, humidity, visibility, pressure and temperature. To understand the weather we need to know how these meteorological variables are changing and how they relate to one another. To understand these relationships it is best to represent weather variables in a simple diagram. Smiling suns do not contain enough information about the weather. On the other hand too many numbers drawn on a single map presents a confusing picture. Weather conditions observed at a city or town are best represented on a map

21 Weather Station Model A station model plot used to represent meteorological conditions near the surface. The station model depicts current weather conditions, cloud cover, wind speed, wind direction, temperature, dew point temperature, atmospheric pressure adjusted to sea level, and the change in pressure over the last three hours.

22 Create Your Station Model