Summary

• 3DVar changes

  • Sfc Temps: no negative impact, safe to turn back on
  • LII.5 88D winds: minimal impact on performance statistics

• Precip Assimilation

  • More robust, more accurate & moist soil moisture

• Prediction Model changes

  • Rad & cloud: more partial cloudiness and better absorption
  • LSM changes: soil & veg better defined, reduced 2-m temperature biases, less drying trend with more low level moisture overall

• Impacts to DGEX minor but generally positive

• Thoroughly tested: 3 seasons, real-time and retrosp.

• NCEP Service Centers recommend implementation

• Request NCEP Director concurrence to implement