Today’s Weather is brought to you by Westly Whithers

Westly Whithers here to give you the latest about our weather. First, you need to know a little about me and how I make my predictions.

Meteorologist A scientist who studies and measures weather conditions. Some call me a weatherman but I went to school to learn more and became a ……… Meteorologist A scientist who studies and measures weather conditions. Meteorology is the study of weather.

Meteorologist Need to know how to use and read the following instruments:

WIND VANE A wind vane shows the direction the wind is coming from. Wind often brings a change in weather… Letters on the wind vane show which way is north, south, east, and west. An arrow turns to point into the wind. If the arrow points north, the wind is from the north. It is a called a north wind. If the arrow points between two directions, both directions are used to tell the wind direction. For example, the wind could be a northeast wind. Say it’s winter. What do you think a wind blowing from the South might bring?

ANEMOMETER An anemometer measures the speed of the wind. The wind pushes the cups and makes them spin. The spinning part of the anemometer is attached to a dial that shows how fast the wind is blowing.

THERMOMETER A thermometer is a tool that measures temperature. Temperature can be measured using Celsius (C) or Fahrenheit (F) scale. Temperature is measured in degrees. The tube thermometer contains a liquid. Heat causes matter to expand, so the liquid expands and moves up the tube when the air temperature gets warmer. The liquid moves down the tube if the air temperature gets cooler. The circle thermometer has pieces of metal inside that expand as the temperature gets hotter. A pointer hooked to these metal pieces moves and points to the temperature. A change in temperature is a sign that rain might fall soon.

HYGROMETER A hygrometer measures humidity (moisture) in the air. What do you think an increase in humidity might mean for the weather?

BAROMETER A barometer measures changes in the air pressure. A rising barometer reading which shows increasing air pressure often occurs right before colder air arrives. Because cold air has less water in it, a rising barometer also means lower humidity and less chance of rain. What would a falling barometer reading mean?

RAIN GAUGE Instrument that collects and measures the amount of precipitation. Rain gauges only indicate rainfall in a localized area. The rain can be measured in centimeters or inches

Satellite A device sent to space to take pictures of the Earth’s weather and relay them back to Earth.

Can you name the weather instrument? What does it do?

Weather Vane Weather Vane finds the wind’s direction

Can you name this weather instrument? What does it do?

Anemometer measures wind speed

Can you name this weather instrument? What does it do?

Rain Gauge measures the amount of liquid precipitation over a period of time.

Can you name this weather instrument? What does it do?

Thermometer measures air temperature

Can you name this weather instrument? What does it do?

Barometer measures pressure of the atmosphere (air pressure)

Weather Instrument that shows which direction the wind is coming from hygrometer Weather Instrument that shows which direction the wind is coming from Weather instrument that collects records the amount of precipitation Weather Instrument that measures air pressure Weather Instrument that measures wind speed Weather Instrument that is used in space to take pictures of the Earth Weather Instrument that measures the (humidity) moisture in the air satellite Weather Instrument that measures temperature

Weather vs. Climate

Air Masses Air moves in large air masses- an air mass is a large body of air that has the same temperature and humidity throughout. Air masses can be warm or cold, humid or dry An air mass takes on the characteristics of the region that it forms over What would an air mass be like that formed over the equator? Northern Canada? There are four air masses that affect our weather- they usually move from west to east When the weather changes in a location, what do you think happens to the air mass?

Fronts The border where two air masses meet is called a front Most weather changes occur along fronts There are two main types of fronts: cold and warm

Fronts A cold front forms where a cold air mass moves over a warm air mass- the warm air mass is pushed up and cooled- when this happens, the water vapor in the air mass condenses quickly and can cause brief heavy rain, thunderstorms, or snow. A warm front forms where a warm air mass moves over a cold air mass- as the warm air slides over, stratus clouds form ahead of the front and can cause long lasting rain or snow storms.

Weather Maps A weather map gives information about what the weather is like in an area

Weather Map Symbols A sun or rain can show the current weather in the area Fronts are shown by red and blue lines Temperatures can be written on a map or shown using color High and low pressure systems are shown with the letters “H” and “L” A high pressure system is formed where an area of cool dense air is surrounded by lower pressure air A low pressure system forms where an area of warm light air is surrounded by higher pressure air Other things a weather map can show include high and low temps and wind speed and direction

A map’s key will tell you what each symbol means. Weather Map Symbols A map’s key will tell you what each symbol means.

Weather Map #1

Weather Map #2

Weather Map #3

Weather Map #4