FAA Advisory Circular 00-45H on page 120 says that’s light right and showery precipitation over more than half the area.

This is a must have circular:

https://www.faa.gov/documentlibrary/media/advisory_circular/ac_00-45h_chg_1.pdf

This is also another good one to have:

https://www.faa.gov/documentlibrary/media/advisory_circular/ac_00-6b.pdf