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? ? ? ? ? ? ? ? {{B}}Forecasting
Methods{{/B}} ? ?There are several different methods that can be used
to create a forecast. The method a forecaster chooses depends upon the
experience of the forecaster, the amount of information available to the
forecaster, the level of difficulty that the forecast situation presents, and
the degree of accuracy or confidence needed in the forecast. ? ?The
first of these methods is the persistence method; the simplest way of producing
a forecast. The persistence method assumes that the conditions at the time of
the forecast will not change. For example, if it is sunny and 87 degree today,
the persistence method predicts that it will be sunny and 87 degree tomorrow. If
two inches of rain fell today, the persistence method would predict two inches
of rain for tomorrow. However, if weather conditions change significantly from
day to day, the persistence method usually breaks down and is not the best
forecasting method to use. ? ?The trends method involves
determining the speed and direction of movement for fronts, high and low
pressure centers, and areas of clouds and precipitation. Using this information,
the forecaster can predict where he or she expects those features to be at some
future time. For example, if a storm system is 1,000 miles west of your location
and moving to the east at 250 miles per day, using the trends method you would
predict it to arrive in your area in 4 days. The trends method works well when
systems continue to move at the same speed in the same direction for a long
period of time. If they slow down, speed up, change intensity, or change
direction, the trends forecast will probably not work as well. ?
?The climatology method is another simple way of producing a forecast. This
method involves averaging weather statistics accumulated over many years to make
the forecast. For example, if you were using the climatology method to predict
the weather for New York City on July 4th, you would go through all the weather
data that has been recorded for every July 4th and take an average. The
climatology method only works well when the weather pattern is similar to that
expected for the chosen time of year. If the pattern is quite unusual for the
given time of year, the climatology method will often fail. ? ?The
analog method is a slightly more complicated method of producing a forecast. It
involves examining today’s forecast scenario and remembering a day in the past
when the weather scenario looked very similar (an analog). The forecaster would
predict that the weather in this forecast will behave the same as it did in the
past. The analog method is difficult to use because it is virtually impossible
to find a predict analog. Various weather features rarely align themselves in
the same locations they were in the previous time. Even small differences
between the current time and the analog can lead to very different
results.
? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? {{B}}Forecasting
Methods{{/B}} ? ?There are several different methods that can be used
to create a forecast. The method a forecaster chooses depends upon the
experience of the forecaster, the amount of information available to the
forecaster, the level of difficulty that the forecast situation presents, and
the degree of accuracy or confidence needed in the forecast. ? ?The
first of these methods is the persistence method; the simplest way of producing
a forecast. The persistence method assumes that the conditions at the time of
the forecast will not change. For example, if it is sunny and 87 degree today,
the persistence method predicts that it will be sunny and 87 degree tomorrow. If
two inches of rain fell today, the persistence method would predict two inches
of rain for tomorrow. However, if weather conditions change significantly from
day to day, the persistence method usually breaks down and is not the best
forecasting method to use. ? ?The trends method involves
determining the speed and direction of movement for fronts, high and low
pressure centers, and areas of clouds and precipitation. Using this information,
the forecaster can predict where he or she expects those features to be at some
future time. For example, if a storm system is 1,000 miles west of your location
and moving to the east at 250 miles per day, using the trends method you would
predict it to arrive in your area in 4 days. The trends method works well when
systems continue to move at the same speed in the same direction for a long
period of time. If they slow down, speed up, change intensity, or change
direction, the trends forecast will probably not work as well. ?
?The climatology method is another simple way of producing a forecast. This
method involves averaging weather statistics accumulated over many years to make
the forecast. For example, if you were using the climatology method to predict
the weather for New York City on July 4th, you would go through all the weather
data that has been recorded for every July 4th and take an average. The
climatology method only works well when the weather pattern is similar to that
expected for the chosen time of year. If the pattern is quite unusual for the
given time of year, the climatology method will often fail. ? ?The
analog method is a slightly more complicated method of producing a forecast. It
involves examining today’s forecast scenario and remembering a day in the past
when the weather scenario looked very similar (an analog). The forecaster would
predict that the weather in this forecast will behave the same as it did in the
past. The analog method is difficult to use because it is virtually impossible
to find a predict analog. Various weather features rarely align themselves in
the same locations they were in the previous time. Even small differences
between the current time and the analog can lead to very different
results.
Persistence method will work well
A.if weather conditions change greatly from day to day. B.if weather conditions do not change much. C.on sunny days. D.on rainy days.
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