The files in this directory contains Global Standarized Precipitation Index (SPI) data derived from precipitation data from the Global Precipitation Climatology Centre (GPCC).
GPCC SPI data are available at the following timescales: 
	
	1, 2, 3, 6, 9, 12, 24, 36, 48, 60, and 72-month. 

The process runs monthly, on the 10th of the month, and generates period-of-record (POR) files in netCDF format. POR for these products are from January 1901 to present. 
GPCC products are available at 1-degree latitude by longitude resolution for the world.

Any inquiries, contact drought.portal@noaa.gov, or 828-271-4800.

Steve Ansari
U.S. Drought Portal Manager
Monitoring Section
NOAA's National Centers for Environmental Information (NCEI)