University of California, Merced
This new experimental implementation of the Palmer Drought Severity Index (PDSI) updates every 5 days using the high-resolution gridMET gridded research dataset and USDA STATSGO soils data. The PDSI is a standardized index based on a simplified soil water balance and estimates relative soil moisture conditions. The magnitude of PDSI indicates the severity of the departure from normal conditions. A PDSI value >4 represents very wet conditions, while a PDSI <-4 represents an extreme drought.
This PDSI uses a new methodology for sub-monthly PDSI, outlined in the Documentation section below.