How was this map produced?

[SeanDonovan1]

[LEFT][/LEFT]Please see attachment.  I saw this map at the UC last year, and am wondering how it is produced.  Is there a step-by-step somewhere?  Thanks.
sean.donovan@fema.dhs.gov

[CoryMacNeil1]

Hi Sean,

Check out this blog on radial flow maps.

I hope this helps.
Cory

[SeanDonovan1]

Thank you Cory, this is what I needed.