Changes to 3D-Var

• Distribute work across processors using the Message Passing Interface (MPI) paradigm

• Fill in between significant levels of RAOBs

• Add non-linear quality control procedures

• Add direct use of satellite radiances keeping GOES 4-layer PW retrievals over land and SSM/I total column water vapor over oceans

• Re-tune background error correlations

• (This is an on-going effort)