Description of variables U_BXS, U_BXE, U_BYS, and U_BYE etc. in wrfbdy

[kwerner]

X/Y means array in the x/y-direction, S/E means starting and ending rows. These are values of U at the valid boundary time. Where there is a letter T in the field name, that means the change of the field in the time period up to the next valid boundary time. See documentation regarding the lateral boundary.