Weather Study Guide Notes
What does a Meteorologist do?
Meteorologists gather information each day about the weather using their weather instruments.
They have been gathering this information for decades. With all this data they gathered they look
for patterns. When they notice a certain pattern for any given day, they can predict the weather.
Many years ago before there were satellites, Doppler Radar and specialized weather instruments
they would use a barometer, thermometer, weather vane, anemometer, hygrometer, and rain
gauge to predict the weather. When they saw the barometer at a certain pressure, the temperature
at a certain level, and the wind blowing at a certain speed and a certain direction they could
generally predict what the weather was going to be like the next day. Now with the all their
special weather instruments added to these other tools they can predict the weather more
accurately.
What does weather consist of?
Weather consists of a number of elements, including:
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Temperature-the degree of heat in the air
Precipitation-crystals or drops that fall from clouds to the ground in forms such as rain
and snow
Wind-air that moves across or horizontally
Clouds-particles of water or ice suspended in air
Humidity-the amount of water vapor in the air
Air Pressure-the amount of force of air over an area
Meteorologists make weather forecasts by examining information that comes from weather
satellites. Twice a day these satellites measure temperature, wind, air pressure, and wind speed
and direction. Then fronts are marked on a map. Precipitation is also indicated on the map.
Different symbols are used. There are thousands of symbols, so looking at the map key is
important. There are some standard symbols such as the symbols for 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 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 represents the direction in
which the warm front is heading.
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 alternating spikes and semi-circles.
Stationary Fronts
 has little/no movement
 denoted by alternating cold/warm frontal symbols
 Associated weather: clear, partly cloudy, cloudy, light precipitation
 usually nothing severe
 If the stationary front starts moving north in the example to the right it will become a
warm front.
 If the stationary front starts moving south in the example to the right it will become a
cold front.
How does a Meteorologist forecast weather?
To forecast the weather a meteorologist looks at the clouds, the wind and weather fronts. Each
type of cloud tells about the weather that is coming.
Cirrus
Thin wispy clouds that are high in the sky point in the direction that the wind blows. There will
be no precipitation falling from these clouds, fair weather lies ahead.
Cumulus clouds
These clouds look like big cotton balls in the sky. They have very large spaces of clear sky in
between them. Normally they don't carry any rain, but during the spring and summer they can
change into cumulonimbus clouds.
Stratus clouds:
Low dark clouds covering the sky, they bring light to moderate precipitation.
Wind in the forecast
Southern winds bring warmer weather.
Northern winds bring cooler and drier weather.
Winds from the east or the west are unpredictable. Meteorologists need to look at the weather
fronts.
Weather Fronts:
Warm Fronts are when a warm air mass meets a cold air mass. The warm air is forced to rise
above the cold air. This collision causes slow rising clouds. At the back edge of the front, rain
clouds develop. These fronts usually move in a northeasterly direction across the U.S.
Cold Fronts happen when a dense mass of cold air pushes into a mass of warm air. The warm air
is lighter and is pushed up and away. Storm clouds (cumulonimbus) form on the front, or
leading edge of the front. This front will move in a southeasterly direction across the U.S.
How does cloud cover help when predicting weather?
One element in predicting weather is to examine the cloud cover. The amount of cloud cover
and the type of clouds help the meteorologists make a forecast,
The following symbols are used to describe the cloud cover
Scattered Clouds
Partly Cloudy
Mostly Cloudy
Overcast
Clear
¼ coverage
½ coverage
mostly covered
completely covered
no clouds
What types of fronts can be found on a weather map?
COLD FRONT
When a cold front passes over an area, the temperature and humidity decrease and the pressure
rises. Precipitation will occur at and/or behind the front. This may fall as rain or snow showers.
The cold front is blue with triangles that point which way it is moving.
WARM FRONT
A warm front means that the temperature and humidity will increase and the air pressure will
rise. Rainfall may increase as the front approaches an area. Then the weather will clear and the
temperature will increase. Sometimes weather conditions may produced fog in the warm air.
The warm front is colored red with semi-circles on one side to show which way it is moving.
STATIONARY FRONT
When a warm or cold front stops moving it becomes a stationary front. During a stationary front,
the sky will be clear, partly cloudy, or cloudy with light precipitation. A stationary front is
shown on a weather map as a combination of a warm and cold front symbol.
What are the symbols for the different kinds of fronts on a weather map?
Cold Front
Warm Front
Stationary Front
How do you identify temperature on a weather map?
Weather maps can include current temperatures, actual low temperatures, or actual high
temperatures. These maps include large numbers located near major cities to indicate the
temperature and a contour of colors. The colors on the map represent different temperature
ranges. The red and orange colors represent warmer temperatures, and the blue colors represent
cooler temperatures.
How can precipitation be identified on a weather map?
Precipitation can be identified on a weather map with bands of color. The color of the
precipitation matches the rate at which it is falling. Green colors mean that there is lighter
precipitation whereas yellow, orange, and red colors mean there is heavier precipitation. Sleet
and freezing rain have a range from pink to red depending on how fast it is falling (red would be
the most intense). Snow has a range of gray colors, with light gray being the most severe.
How can you use the information about fronts, temperature, and precipitation on a
weather map to forecast upcoming weather conditions?
In order to make predictions about the weather, you need to know information about fronts along
with the temperature and precipitation they bring. For example, if you know that a cold front has
recently passed over your area, then you know that the temperatures in your area will decrease
and precipitation is likely to occur.
How do we know if a weather forecast is accurate?
Meteorologists gather a great deal of information when forecasting the weather. Because of this,
weather forecasts are less accurate the further away they are. Forecasts made for 1-2 days in
advance regarding temperature and precipitation are the most accurate. Forecasts for 3-7 days in
the future are less accurate and more likely to change.
How do we use records of weather conditions to predict weather patterns throughout the
year?
Daily records are kept on the weather and are available at many online websites. Recording the
data allows us to find the daily averages and to also see specific patterns that may occur in
certain regions. By studying the weather patterns that have happened in the past, we are better
able to predict what will happen in the future. Weather patterns often follow a specific
predictable cycle.