Cycle 37r2


Implementation date               

18 May 2011 See Newsletter No.128
IFS Documentation CY37R2    
Detailed description of changes    
Key characteristics of our current forecasting system  

Horizontal (unchanged)

  • Atmospheric
    • HRES: TL1279
    • ENS: Leg A T639, Leg B T319, Leg C T255
  • Wave
    • HRES: 0.25 degrees
    • ENS: 0.5 degrees


  • Atmospheric
    • HRES: L91
    • ENS: L62

Data set affected

Score card Comparison of scores of model cycle
Meteorological changes


  • Background error variances from the ensemble of data assimilations (EDA) used by the deterministic 4D-Var assimilation
  • Improvements to cloud scheme formulation
  • Changes to all-sky assimilation of microwave data
  • Reduction of AMSU-A observation errors and adjustments to MODIS AMVs
  • Accounting for tangent point drift in GPS radio occultation


Meteorological impacts
  • Tropical wind scores improved
  • Impact on humidity scores in the extra-tropics in the early forecast range
Technical changes
  • WMO FM-92 GRIB edition 2 (GRIB-2)
  • GRIB-1 model-level data will no longer be produced and disseminated
Model ID 37r2
New disseminated model output


Discontinued disseminated model output None
e-suite experiment number 0053