Deck 14: Weather Forecasting

Question 1

Numerical weather prediction models begin with an __________ and produce a __________.

A)prog;analysis
B)prog;meteogram
C)meteogram;prog
D)analysis;prog

Answer 1

D

Question 2

Suppose there are two cloud layers above you.The lower cloud layer is moving from a westerly direction,while the higher cloud layer is moving from a northwesterly direction.From this observation you conclude that the wind is __________ with height and __________ advection is occurring between the cloud layers.

A)backing,cold
B)backing,warm
C)veering,cold
D)veering,warm

Answer 2

D

Question 3

For a forecast to show skill it must:

A)be better than one based on persistence or climatology.
B)be accurate to within 2 ^oC of the predicted temperature.
C)be accurate for over more than 90% of the forecast area.
D)use the analogue method of forecasting.
E)use a probability.

Answer 3

A

Question 4

If you wanted to make a persistence forecast of minimum and maximum temperatures for a particular city,which type of chart would be most helpful?

A)surface chart
B)meteogram
C)500 mb chart
D)adiabatic chart
E)Doppler radar display

Question 5

Smaller grid spacing in numerical weather prediction models typically leads to:

A)reduced accuracy in predicting the location of large anticyclones.
B)better prediction of small-scale weather phenomena.
C)better prediction of jet streams.
D)both a and c

Question 6

A weather warning indicates that:

A)the atmospheric conditions are favorable for hazardous weather over a particular region.
B)hazardous weather is either imminent or occurring within the forecast area.
C)hazardous weather is likely to occur within the forecast area during the next 24 hours.
D)hazardous weather is frequently observed in a particular region.

Question 7

The least accurate forecast method of predicting the weather two days into the future during changeable weather conditions is usually the:

A)trend method.
B)persistence forecast.
C)analogue method.
D)prediction by weather types.
E)numerical weather prediction.

Question 8

Which of the following is presently a problem with modern-day weather predictions?

A)computer forecast models make assumptions about the atmosphere that are not always correct.
B)there are regions of the world where only space observations are available.
C)computer models do not always adequately interpret the surface's influence on the weather.
D)the distance between grid points on some models is too large to pick up smaller-scale weather features such as thunderstorms.
E)all of the above

Question 9

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,you would have made a:

A)forecast based on the analogue method.
B)persistence forecast.
C)forecast based on weather types.
D)probability forecast.
E)climatological forecast.

Question 10

An analysis is:

A)a forecast chart that shows the atmosphere at some future time.
B)a forecast chart that compares past weather maps with those of the present.
C)a surface or upper-level chart that interprets the present weather patterns.
D)a forecast method used in long range weather prediction.
E)a method used to determine skill in predicting the weather.

Question 11

A persistence forecast could be quite accurate when:

A)a frontal system approaches your location at constant speed.
B)you are positioned in the middle of a large,stationary air mass.
C)the weather has been unusually cold for several days.
D)upper level winds blow straight from west to east.

Question 12

Warm advection is most likely to occur:

A)in the center of a cut-off low.
B)from the surface up to the 500 mb level ahead of an advancing warm front.
C)behind a cold front.
D)where the winds back with height.
E)on the western side of a shortwave trough at the 500 mb level.

Question 13

Suppose it is warm and raining,and a cold front is moving toward your location.Directly behind the cold front it is cold and snowing.Still further behind the front the weather is cold and clearing.If the front is scheduled to pass your area in 6 hours,a persistence forecast for your area for 12 hours from now would be:

A)cold and snowing.
B)cold and clearing.
C)cold and cloudy.
D)warm and raining.
E)not enough information on which to base a forecast.

Question 14

A forecast of an extended period of dry weather would be made for a region beneath:

A)an upper-level trough.
B)the polar jet stream.
C)a cold pool of air aloft.
D)an upper-level ridge.
E)a shortwave trough.

Question 15

A probability forecast that calls for a "40 percent chance of rain" means that:

A)there is a 40 percent chance that it will not rain within the forecast area.
B)there is a 40 percent chance that any random place in the forecast area will receive measurable rain.
C)it will rain on 40 percent of the forecast area.
D)it will rain during 40 percent of the time over the forecast area.

Question 16

When several numerical weather prediction models produce similar progs,

A)a forecaster has little faith in the model predictions.
B)more confidence can be placed in the forecast.
C)the forecast is considered robust.
D)both b and c

Question 17

A forecast method that compares past weather maps and weather patterns to those of the present is:

A)persistence forecasting.
B)the analogue method.
C)the trend method.
D)nowcasting.

Question 18

When making a forecast,a meteorologist typically examines:

A)surface charts.
B)upper-air charts.
C)radar displays.
D)satellite imagery.
E)all of the above

Question 19

By examining a surface map,the movement of a surface low pressure area can be predicted based upon the:

A)orientation of the isobars in the warm sector.
B)region of greatest pressure decrease.
C)movement during the previous 6 hours.
D)all of the above

Question 20

An accurate forecast:

A)always shows skill.
B)may or may not show skill.
C)never shows skill.
D)requires complex computer equipment.

Question 21

Describe four different types of weather forecasting methods and give an example of each.

Question 22

A prog is a chart that interprets the current state of the atmosphere.

Question 23

With all other factors being equal,will a cloudy day have a higher or lower maximum temperature then a clear day? How about the minimum temperature during a cloudy vs.clear night? Explain.

Question 24

Assuming you know last night's minimum temperature,what weather information would you use to predict tonight's minimum temperature?

Question 25

Modern computer forecasting models with very small grid spacing can only resolve large-scale features like jet streams and large highs and lows.

Question 26

What local signs would you look for to predict the approach of a low pressure center or a weather front?

Question 27

Low 1000-500 mb thicknesses correspond to cold air,while high thicknesses correspond to warm air.

Question 28

A "forecast based on weather types" is a forecasting technique that produces several versions of a forecast model,each beginning with slightly different weather information to reflect errors in the measurements.

Question 29

Weather forecast that predicts that the future weather will be the same as the present weather is called a persistence forecast.

Question 30

List some of the factors that affect the accuracy of atmospheric models.

Question 31

Explain how observed teleconnection patterns can help in the preparation of a seasonal weather forecast.

Question 32

The forecasting of weather by a computer is known as numerical weather prediction.

Question 33

Describe the data and tools that a meteorologist assembles prior to making a weather forecast.

Question 34

Very short-range forecasts often utilize the ensemble forecasting method.

Question 35

If there is a chance for tornadoes tomorrow,a weather watch would probably be issued.

Question 36

What type of forecast method do you think would be most appropriate for a short range (6 to 12 hours),a medium range (24 to 48 hours),a long range (5 to 10 days),or a seasonal (3 month)forecast?

Question 37

About how far apart do you think weather observing stations should be in order to accurately depict a middle latitude storm and to be able to forecast the storm's movement?

Question 38

Wintertime CAPE values tend to be much larger than summertime values.

Question 39

List some of the ways that you can predict the future movement of surface middle latitude storms.

Question 40

The greatest improvement in forecasting skill during the past 30 years has been made in forecasting severe storm warnings for hurricanes and tornadoes.

Question 41

Describe the relationship between dew point and minimum temperatures.