Realtime chi heating fields are computed from 6 hourly operational NCEP analyses. The generalized chi problem is run for each available time and the diabatic heating is calculated as a residual of the thermodynamic equation. Technical details will soon be available.

The realtime chi heating has been used to produce good medium-range forecasts of the low-frequency atmosphere.

Anomalies are defined as a departure from the first 3 harmonics of the heating's seasonal cycle as determined from 1969-1998.

The CDC maproom has similar products for OLR.