It also works well in places like southern California, where summertime weather conditions vary little from day to day. 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. For example, it is often the case that one hot and dry month will be followed by another hot and dry month. So, making persistence forecasts for monthly and seasonal weather conditions can have some skill. Some of the other forecasting methods, such as numerical weather prediction, lose all their skill for forecasts longer than 10 days.
Important surface features to consider when making a forecast.
There are several key surface features to consider when making a forecast. We will begin this discussion with the anticyclone, which is a high pressure center where the pressure has been measured to be the highest relative to its surroundings. High pressure centers often represent the centers of anticyclones. With air moving away from this region, air must sink from above to replace it. This sinking motion leads to generally fair skies and no precipitation near the high.