阅读理解-第四十三篇 天气预报的方法

+第四十三篇Forecast ing〔预报〕Method s〔方法〕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〔精确〕or confidence〔信任〕needed in the forecast.The first of these methods is the persistence〔持续〕method; the simplest way of producing a forecast.The persistence method assume s〔假定〕that the conditions at the time of the forecast will not change. For example ,if it. is sunny and 87 degrees today ,the persistence method predict s〔预测〕that it will be sunny and 87 degrees tomorrow. If two inches of rain fell today ,the persistence method would predict two inches of rain for tomorrow. However , if weather conditions change significant ly（重要的）from day to day ,the persistence method usually breaks down and is not the best forecasting method to use.The trend s（趋势）method involves determining the speed and direction of movement for fronts , high and low pressure（压力）centers , and areas of clouds and precipitation. Using this information ,the forecaster can predict where he or she expects those features（特征）to be at some future time. For example , if a storm system is l ,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（强度）, or change direction ,the trends forecast will probably not work as well.The climatology（气候学）method is another simple way of producing a forecast. This method involves averaging weather statistics（统计）accumulate d 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 theweather 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(模拟) method is a slightly more complicate d（复杂）method of producing a forecast. It involves examining today's forecast scenario（方案）and remembering a day in the past when the weather scenarlo looked very similar〔an analog〕.The forecaster would predict that the weather in this forecast will behave the same as it did in the predict. 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 as they were in the previous time. Even small differences between the current time and the analog can lead to very different results.练习：1. What factor is NOT mention ed in choosing a forecast ing method?A Imagination(想象力)of the forecaster.B Necessary amount of information.C Practical knowledge of the forecaster.D Degree of difficulty involved in forecasting..第一题：在选择天气预报模式时没有提到什么因素？A、预报员的想象力B、需要大量的信息C、预报员的实践知识D、包含在预报中的困难程度选择A31. What of the following factors is NOT mentioned in choosing a forecasting method?A. Necessary amount of information.B. Degree of difficulty involved in forecasting.C. Practical knowledge of the forecaster.D. Creativity of the forecaster.2013年考试第一题：在选择一个预报模式中下列因素什么没有提到？A、需要大量的信息B、包含在预报中的困难程度C、预报员的实践知识D、预报员的创造力2. Persistence method will work wellA 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.第二题：持续模式非常好A、如果气候条件一天天变化巨大B、如果气候条件没有变化很大C、在晴天D、在雨天选择：B32. The persistence method fails to work well whenA. it is rainy.B. it is sunny.C. weather conditions stay stable.D. weather conditions change greatly.2013年考试第二题：什么时候持续模式不好？A、在雨天B、在晴天C、天气状况稳定D、天气状况变化巨大3. The limitation of the trends method is the same as the persistence method in thatA it makes predictions about weather.B it makes predictions about precipitation.C the weather features need to be well defined.第三题：趋势模式在哪方面与持续模式有同样的限制？A、预报天气B、预报降雨量C、天气特征需要规定是好的D the weather features need to be constannt for a long period of time.33. The trends method works well whenA. weather features are constant for a long period of time.B. weather features are defined well.C. predictions on precipitation are accurate.D. the speed and direction of movement are predicable.2013年考试第三题：什么时候趋势模式好？A、天气特征持续很长一段时间B、天气特征需要规定是好的C、预测降雨量是精确的D、运动的速度和方向是可预测的4. Which method may involve historical weather data?A Tbe trends method.B The analog method.C Both climatology method and analog method.D The trends method and the persistence method.34. The analog method should not be used in making a weather forecast whenA. the analog looks complicated.B. the current weather scenario is different from the analog.C. the analog is more than 10 years old.D. the current weather scenario is exactly the same as the analog.5. It will be impossible to make weather forecast using the analog methodA when the current weather scenario differ s（与…不同）from the analog.B when the current weather scenario is the same as the analog.C when the analog is over ten years old.D when the analog is a simple repetition of the current weather scenario.35. Historical weather data are necessary inA. the persistence method and the trends method.B. the trends method and the climatology method.C. the climatology method and the analog method.D. The persistence method and the analog method.第四十三篇天气预报的方法天气预报可用几种不同的方式来制作。