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MET 121 Final Exam (Chs. 9-11) Questions and
Correct Answers/ Latest Update / Already Graded
What is the function of the National Center for Environmental Prediction?
Ans: The National Center for Environmental Prediction (NCEP) receives global
weather data from several world meteorological centers many times each day.
The data are analyzed and plotted, and forecasts are prepared and transmitted to
National Center for Environmental Prediction (NCEP).
How does a weather watch differ from a weather warning?
Ans: Weather watch- Indicates that atmospheric conditions favor hazardous
weather occurring over a particular region during a specified time period. These
hazards may or may not actually develop, and their timing and location are
uncertain, so a watch simply means be on "watch" for that threat and to be
prepared to act if necessary
Weather Warning- Indicates that the hazard now occurring or imminent is
considered to be a threat to life and/or property (tornadoes, thunderstorms, etc)
List at least four tools a weather forecaster might use when making a short-range
forecast
Ans: Doppler radar, surface weather, maps & upper air winds
How does a prog differ from an analysis?
Ans: Analysis is what is going on right now and a prog is a forecast
In what ways have high-speed computers assisted the meteorologist in making
weather forecasts?
© 2025/ 2026 | ® All rights reserved
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Ans: Computer-generated weather forecasts can analyze large quantities of data
extremely fast. Each day the many thousands of observations transmitted to
NCEP are fed into a high-speed computer, which plots and draws lines on surface
and upper-air charts. Meteorologists interpret the weather patterns and then
correct any errors that may be present. The routine daily forecasting of weather
by the computer has come to be known as numerical weather prediction. To help
forecasters handle all the available charts and maps, high-speed data modeling
systems using computers are employed.
How are computer-generated forecasts prepared?
Ans: The models are programmed into the computer, and surface and upper-air
observations of temperature, pressure, moisture, winds, and air density are fed
into the equations. To determine how each of these variables will change, each
equation is solved for a small increment of future time, say, 5 minutes, for a large
number of locations called grid points; each situated a given distance apart. In
addition, each equation is solved for as many as 50 levels in the atmosphere. The
results of these computations are then fed back into the original equations. The
computer again solves the equations with the new "data," thus predicting weather
over the following 5 minutes. The computer then analyzes the data and draws the
projected positions of pressure systems with their isobars or contour lines.
What are some of the problems associated with computer-model forecasts?
Ans: Observations over uninhabited regions
Weather systems crossing boundaries of models
Forecasting small scale evens with larger grids
Suppose that where you live, the middle of January is typically several degrees
warmer than the rest of the month. If you forecast this "January thaw" for the
middle of next January, what type of weather forecast will you have made?
Ans: Climatological
© 2025/ 2026 | ® All rights reserved
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Describe four methods of forecasting the weather and give an example for each
one
Ans: Persistence Forecasts- A prediction that future weather will be the same
as present weather
Steady-state- Surface weather systems tend to move in same direction and at
approximately the same speed as they have been moving, providing no evidence
exists to indicate otherwise
Analogue- Relies on the fact that existing features on a weather chart may
strongly resemble features that produced certain weather conditions sometime in
the past
Statistical- Known as Model Output Statistics (MOS), these predictions, in effect,
are statistically weighted analogue forecast corrections incorporated into the
computer model output
How does pattern recognition aid a forecaster in making a prediction?
Ans: Patterns recognition aid a forecaster in determining patterns of divergence
and convergence aloft, computer progs, comma clouds observed from satellite
observations, and Doppler radar observations of precipitation.
How can ensemble forecasts improve medium-range forecasts?
Ans: Ensemble forecasting is a technique based on running several forecast
models (or different versions of a single model), each beginning with slightly
different weather information to reflect errors in the measurements. If the
different versions agree fairly well, a forecaster can place a high degree of
confidence in the forecast. A low degree of confidence means that the models do
not agree.
Explain how teleconnections are used in making a long-range seasonal outlook.
© 2025/ 2026 | ® All rights reserved
MET 121 Final Exam (Chs. 9-11) Questions and
Correct Answers/ Latest Update / Already Graded
What is the function of the National Center for Environmental Prediction?
Ans: The National Center for Environmental Prediction (NCEP) receives global
weather data from several world meteorological centers many times each day.
The data are analyzed and plotted, and forecasts are prepared and transmitted to
National Center for Environmental Prediction (NCEP).
How does a weather watch differ from a weather warning?
Ans: Weather watch- Indicates that atmospheric conditions favor hazardous
weather occurring over a particular region during a specified time period. These
hazards may or may not actually develop, and their timing and location are
uncertain, so a watch simply means be on "watch" for that threat and to be
prepared to act if necessary
Weather Warning- Indicates that the hazard now occurring or imminent is
considered to be a threat to life and/or property (tornadoes, thunderstorms, etc)
List at least four tools a weather forecaster might use when making a short-range
forecast
Ans: Doppler radar, surface weather, maps & upper air winds
How does a prog differ from an analysis?
Ans: Analysis is what is going on right now and a prog is a forecast
In what ways have high-speed computers assisted the meteorologist in making
weather forecasts?
© 2025/ 2026 | ® All rights reserved
, 2 | Page
Ans: Computer-generated weather forecasts can analyze large quantities of data
extremely fast. Each day the many thousands of observations transmitted to
NCEP are fed into a high-speed computer, which plots and draws lines on surface
and upper-air charts. Meteorologists interpret the weather patterns and then
correct any errors that may be present. The routine daily forecasting of weather
by the computer has come to be known as numerical weather prediction. To help
forecasters handle all the available charts and maps, high-speed data modeling
systems using computers are employed.
How are computer-generated forecasts prepared?
Ans: The models are programmed into the computer, and surface and upper-air
observations of temperature, pressure, moisture, winds, and air density are fed
into the equations. To determine how each of these variables will change, each
equation is solved for a small increment of future time, say, 5 minutes, for a large
number of locations called grid points; each situated a given distance apart. In
addition, each equation is solved for as many as 50 levels in the atmosphere. The
results of these computations are then fed back into the original equations. The
computer again solves the equations with the new "data," thus predicting weather
over the following 5 minutes. The computer then analyzes the data and draws the
projected positions of pressure systems with their isobars or contour lines.
What are some of the problems associated with computer-model forecasts?
Ans: Observations over uninhabited regions
Weather systems crossing boundaries of models
Forecasting small scale evens with larger grids
Suppose that where you live, the middle of January is typically several degrees
warmer than the rest of the month. If you forecast this "January thaw" for the
middle of next January, what type of weather forecast will you have made?
Ans: Climatological
© 2025/ 2026 | ® All rights reserved
, 3 | Page
Describe four methods of forecasting the weather and give an example for each
one
Ans: Persistence Forecasts- A prediction that future weather will be the same
as present weather
Steady-state- Surface weather systems tend to move in same direction and at
approximately the same speed as they have been moving, providing no evidence
exists to indicate otherwise
Analogue- Relies on the fact that existing features on a weather chart may
strongly resemble features that produced certain weather conditions sometime in
the past
Statistical- Known as Model Output Statistics (MOS), these predictions, in effect,
are statistically weighted analogue forecast corrections incorporated into the
computer model output
How does pattern recognition aid a forecaster in making a prediction?
Ans: Patterns recognition aid a forecaster in determining patterns of divergence
and convergence aloft, computer progs, comma clouds observed from satellite
observations, and Doppler radar observations of precipitation.
How can ensemble forecasts improve medium-range forecasts?
Ans: Ensemble forecasting is a technique based on running several forecast
models (or different versions of a single model), each beginning with slightly
different weather information to reflect errors in the measurements. If the
different versions agree fairly well, a forecaster can place a high degree of
confidence in the forecast. A low degree of confidence means that the models do
not agree.
Explain how teleconnections are used in making a long-range seasonal outlook.
© 2025/ 2026 | ® All rights reserved
