Keetch-Byram Drought Index Seasonal Initialization
The Climate Prediction Center of the National Weather Service maintains estimates for a number of parameters associated with the Palmer Drought Index. These data can be used to determine a starting value for KBDI.
These data are available at:
We have developed an automated system to provide recommended KBDI initialization values for each of the four regions defined by the CPC.
Click the region below for the summary:
Central Climate Region
Eastern Climate Region
Western Climate Region
Southern Climate Region
KBDI starting values are assumed to be linearly related to percentage changes soil moisture expressed as a proportion of field capacity. The following equation is used to estimate KBDI:
KBDI = 8 * (100 - FC).
Click the CPC link above for a complete description of the climate divisions