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Precipitation

Precipitation
Anomaly
Monthly OLR
Pentad OLR
Percentiles
Persistence
Seasonal
Seasonal OLR
SPI
Station Data CPC
Station Obs
WASP Indices

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Global Precipitation

This series of charts includes global analyses of surface and near-surface air temperature as well as links to data for specific stations.    Select desired field from menu at left.

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Data for these analyses was obtained from the US National Centers for Environmental Prediction, Climate Prediction Center.

Aids to interpreting plots:

Definitions
Climatology The long-term average of a given variable, often the 30-year period 1961-1990.
Anomaly The difference between the observed value of a variable and its climatological value.
OLR An abbreviastion for "Outgoing Longwave Radiation".  Anomalies in OLR can be related to cloud cover and precipitation.  Negative OLR anomalies generally indicate increased cloudiness and likelihood of precipitation while positive anomalies imply decreased cloudiness.   The relationship between OLR anomalies and precipitation holds most strongly in tropical regions.
Pentad A 5-day average of a variable, starting from 1-5 Jan, 6-10 Jan, ..., 27-31 Dec.  On plots using pentad data, the date for the "middle" of the pentad is displayed: 3 Jan, 8 Jan, ... , 29 Dec.
Percentiles Percentiles represent a ranking of the data over a given base period.  Data in the zeroth percentile have the lowest value in the base period while those at the hundreth percentile have the highest value during the base period.  On some plots the percentiles are displayed from 0 to 1 (the percentiles are divided by 100).