With a need for a database with little or no missing data to calculate the scPDSI, even the stringent criteria we used in separating out the stations for the Drought Risk Atlas led to issues in calculating the scPDSI. Of the 3059 stations in the Drought Risk Atlas, not all of them had the necessary data to calculate the scPDSI. Temperature and precipitation data are needed, and many stations used in the SPI and Deciles were stations that historically had recorded just precipitation. Stations recording both precipitation and temperature were identified and the gaps in the data were noted. It was noted that even small gaps would cause problems in the calculations, and a serially complete dataset using data estimations would be ideal.
The High Plains Regional Climate Center (HPRCC) has developed several methodologies to provide data estimates as part of their data quality control and assurance programs. Using these techniques, the HPRCC provided estimates for the missing Drought Risk Atlas data, making the data serially complete. For the scPDSI, the following stations were obtained:
- 2173 stations where 90% or more of the temperature data were available, leaving 10% or less estimated.
- 2296 stations where 80% or more of the temperature data were available, leaving 123 stations where up to 20% of the data were estimated.
See more information about the Palmer Drought Severity Index