Spring Upgrade Package: Prediction Model (Eta)

• Noah LSM upgrades in the NAM prediction model (Eta)

• To address low-level temperature and humidity biases & drift during different seasons

  • Summer: warm/dry bias during day, typically over areas with larger greenness fractions
  • Summer: drying trend in PW and low level moisture with forecast range
  • Winter: cold bias during night, typically under calm/clear conditions especially over snowpack, and during day over shallow/melting snowpack