VWAP Bands Converging. What does it mean? Can it be Alerted?

[thefollower]

Using the stock VWAP study. On a chart one sees the upper and lower bands coming together and touching the VWAP line. Many times this convergence indicates a change in an upward direction. So...

1) What does this intersection actually mean? Given the upper/lower bands represent standard deviation, why would they come together to indicate 0% deviation. I am lost in the math on this one.

2) How can I create and study/scan to alert when these there lines converge?

Much appreciated
Stephen

 

[BenTen]

Would need to see some examples of what you're talking about.