How to decide the sizes of nested domains?

[g_vijayan]

Hi,
I am trying to run WRF with three nested domains of resolutions 18km, 6km and 2km.
I need the extent of the outermost domain to be 80 degrees longitudinally, ie from east to west, and 55 degrees latitudinally.
Are there any constraints to be kept in mind while deciding the extents of the inner domains. For eg, should the extent be some ratio of the extent of the parent domain? For my case, since the domain ratio is 3, should my second domain have a longitudinal extent of at least 27 degrees?
Is there any constrain like that, or can we choose the sizes, ie, extents of our domains as per the location of our area of interest that we plan to study?
Are there any other things/ constraints/ rules we need to keep in mind while deciding the domain configuration?

Kindly help me out with these queries.

Thankyou!

 

[kwerner]

Hi,
I'm in the process of going through and making sure no posts have been overlooked in recent months and I came across this one. I am truly sorry you never received a response. I assume you've found a way to move forward, but in case you haven't, I would suggest looking at this page, which provides best practice suggestions for all of the namelist.wps parameters. You can also look at this presentation, which discusses some of that, as well.