----is often the case,the weather has turned out well as exp

A
as is often the case
情况常常如此；这是常有的事；通常就是这样
as多用于固定搭配中：as is often the
case(这是常有的事)
固定搭配
这句话的翻译是“这是常有的事,天气如所预期的那样变好了.”
这里面turn out是词组,意思有“生产；结果是；关掉；出动；驱逐”这里是结果的意思.由于主语是weather 所以用被动.