Floating point exception in phys/module_mp_radar.F with debugging option -D

[jackbartlett20]

Describe the bug
Line 225 in phys/module_mp_radar.F (xoamh = 1./xam_h) triggers a floating point exception when debugging with -D and using any microphysics scheme which calls radar_init except the UDM scheme.

It seems this is because xam_h is only given a value in the UDM scheme, so any other scheme which calls radar_init will naturally lead to a floating point exception.

It's not a major issue because the variable xam_h is only used by the UDM scheme in which it is initialised, but it means you cannot debug with option -D when using some microphysics schemes.

To Reproduce

1. Do ./configure -D, then compile
2. Try to run with a microphysics scheme except UDM that calls radar_init, e.g. Thompson

This is my first time raising an issue, so I hope I'm doing it right!

[dudhia]

Sounds valid since UDM was just added. Can you do a github pull request? Or do you have a fixed code?