Weather Stations and Weather Maps Geography 12 Ms. Kenkel

Terms to know The scientists who study the weather and climate are called meteorologists. The study of weather and climate is meteorology

Fronts A front is a leading edge of an air mass. Review: What is an air mass?????? A warm front is the front of a warm air mass. A cold front is the front of a colder air mass.

Weather Stations A weather station is a facility with instruments and equipment for observing weather conditions to provide weather forecasts and to study the weather and climate of a region. Weather: Daily meteorological occurrences in a region. Climate: Average temperature and precipitation patterns of a region.

Weather Stations Measurements taken include: Temperature Pressure Wind Speed Wind Direction Precipitation totals Humidity These measurements are taken at least one an hour. Weather stations are often found at airports.

Weather Stations Instruments are sheltered from direct sunlight and precipitation in a box called a stevenson screen. Stevenson screens are kept off the ground to give more accurate measurements.

Weather Stations Instruments that are located in a Weather Station include: Thermometer (temperature) Barometer (Pressure) Hygrometer (Humidity) Anemometer (Wind Speed) Wind Vane (Wind Direction) Rain Gauge (Precipitation amounts)

Weather Station Maps The information that a measure station gives us is turned into a map. These maps give us a lot of information about weather conditions in a given location at a given time. By looking at a weather station map we can tell the following things. Cloud Cover Wind Speed Wind Direction Dew Point Temperature Pressure Whether pressure is rising or falling 994 15 6 +10

Weather Maps On Weather maps that show a large area (ie. North America) we will see lines running across the map as well as the weather station models. These lines are called ISOBARS. They connect areas of equal pressure. The closer the isobars the stronger the winds in that area.

Pressure Pressure can be measured in millibars (mbs) or kilopascals (kPa). (We will use only kPa) When pressure is higher than normal we call it a high or anti cyclone) When pressure is lower than normal it is called a low of cyclone. REMEMBER: High pressure=clear skies Low pressure=wet,windy conditions Extreme low pressure=tornado/hurricane

Determining Pressure To determine the correct air pressure at a weather station one must either add a 9 or 10 to the numbers appearing on the station. RULE: If the first number is less than 5 add a 10 If the first number is 5 or more add a 9

Remember it is the number in the top right corner of the station Determining Pressure If the station says 992 Remember it is the number in the top right corner of the station Step 1: Decide whether to add a 9 or 10 to the number. First number is a 9 so we add a 9 = 9992 Step 2: Add a period so that it is to two decimal point = 99.92 Step 3: Add the units =99.92kpa

TRY It! 987 338

987 Step 1: First number is 5 or above so add a 9 =9987 Step 2: Add a period so that there is ONE decimal =99.87 Step 3: Add units =99.87mkpa

338 Step 1: First number (3) is below 5 so add a 10 =10338 Step 2: Add period so that there is one decimal point =103.38 Step 3: Add units =103.38kpa