Weather Stations and Weather Maps Geography 12 Ms

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 ● ● ● ● 15 6 994 +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 (k. Pa). (We will use only k. Pa) ● 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

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. 92 kpa

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. 87 mkpa

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. 38 kpa