Upgrades to MSAS in AWIPS Build 5.0 fall into three main categories:

1) updates to the background (or "first guess") grid to utilize Eta, 
   instead of NGM forecasts;
2) widening of the observation-time window to allow for the ingest 
   of more Mexican and mesonet observations; and
3) added logic to assign elevations to maritime data in the Great 
   Lakes with "missing flags" in their elevation field

Build 5.0 will also include:

- MSAS QC (QCMS) messages encoded into SHEF;
- displays of all three MSAS sea-level pressure analyses (NWS SLP, 
  MSAS SLP, and Altimeter);
- two new derived fields (potential temperature advection and 
  equivalent potential temperature advection); 
- displays of the observations used in each analyzed field (along 
  with QC results);
- substantial performance enhancements, particularly for those programs
  writing netCDF files across the AWIPS network (e.g. qcstg1_2); and
- improved failover scripts which allow MSAS to continue running after
  DS failovers.

More information on the changes made to the MSAS software, scripts, and 
documentation is available on request.