Standardized Precipitation Index (SPI) ProductsEntry ID: WRCC_DRI_PRECIPITATION
Abstract: The standardized precipitation index data set may be accessed via
World Wide Web. Link to: http://www.wrcc.dri.edu/spi/spi.html
Five quantities are computed as part of the Standardized Precipitation
Index procedure. They follow as a consequence of an observation made
by Dr. Tom McKee, State Climatologist for Colorado, that users are
interested in one or several among the following types of ... information:
What is the absolute amount of precipitation?
What is the absolute departure from climatology?
What is the relative departure from climatology?
How frequent are such departures from climatology?
How can this be expressed as a single number comparable across climates?
The Standardized Precipitation Index was designed to explicitly
express the fact that it is possible to simultaneously experience wet
conditions on one or more time scales, and dry conditions at other
time scales, often a difficult concept to convey in simple terms to
decision-makers. Consequently, a separate SPI value is calculated for
a selection of time scales, covering the last 1, 2, 3, 4, 5, 6, 7, 8,
9, 10, 11, 12, 15, 18, 24, 30, 36, 48, 60, and 72 months, and ending
on the last day of the latest month.
A more detailed description of this data set is available on-line.
Link to: http://www.wrcc.dri.edu/spi/explanation.html
More drought information is available from the National Drought
Mitagation Center. http://www.drought.unl.edu/index.htm
(Summary adapted from the WRCC Home Page)
(Click for Interactive Map)
Data Set Citation
Dataset Originator/Creator: Tom Mckee, Nolan Doesken and John Kleist
Dataset Title: Standardized Precipitation Index
Dataset Release Date: 1993
Dataset Release Place: Colorado
Dataset Publisher: Colorado Climate CenterOnline Resource: http://www.wrcc.dri.edu/spi/spi.html
Start Date: 1895-01-01
ATMOSPHERE > ATMOSPHERIC PHENOMENA > DROUGHT
ATMOSPHERE > PRECIPITATION > PRECIPITATION AMOUNT
ATMOSPHERE > PRECIPITATION > PRECIPITATION ANOMALIES
CLIMATE INDICATORS > ATMOSPHERIC/OCEAN INDICATORS > PRECIPITATION INDICES > STANDARDIZED PRECIPITATION INDEX
CLIMATE INDICATORS > ATMOSPHERIC/OCEAN INDICATORS > PRECIPITATION INDICES > STANDARDIZED PRECIPITATION INDEX > SPI
ISO Topic Category
Data Set Progress
Distribution Media: WWW
Distribution Format: GIF
Role: DIF AUTHOR
Email: Scott.A.Ritz at nasa.gov
NASA Goddard Space Flight Center Global Change Master Directory
Province or State: Maryland
Postal Code: 20771
Guttman, N.B., 1998. Comparing the Palmer Drought Index and the
Standardized Precipitation Index. Journal of the American Water
Resources Association, 34(1), 113-121.
Guttman, N.B., 1999. Accepting the Standardized Precipitation
Index: A calculation algorithm. Journal of the American Water
Resources Association, 35(2), 311-322.
McKee, T.B., N.J. Doesken, and J. Kleist, 1993. The relationship of
drought frequency and duration ot time scales. Eighth Conference on
Applied Climatology, American Meteorological Society, Jan 17-23, 1993,
Anaheim CA, pp. 179-186.
McKee, T.B., N.J. Doesken, and J. Kleist, 1995. Drought monitoring
with multiple time scales. Ninth Conference on Applied Climatology,
American Meteorological Society, Jan 15-20, 1995, Dallas TX,
Wilkes, D.S., 1995. Statistical methods in the atmospheric
sciences: An introduction. Academic Press, 467 pp.
Creation and Review Dates
Last DIF Revision Date: 2004-09-23