What does "Should" mean when it starts a sentence?

[Tryna learn English]

for example:

Should you need to know more about the rain or snow than a Google Now card can deliver, the Weather Channel revamp is ready at the source.

source: an engadget article about the updated the weather channel app for android

[SoothingDave]

"Should you" means "if you should."

[magdalena]

It means that the author is not sure you will want/ need to know. Should you need my help (if you need my help, although I don't think you will).

[Tryna learn English]

Thanks