Description:
The maps above show the monthly station precipitation anomalies (top), percentiles (middle), and percent of median (bottom) with respect to the 1971-2000 climatology. The percentiles shown in the middle plot indicate a ranking of  precipitation anomalies (for the month shown on plot) with the 0th percentile being the driest on record and the 100th percentile (shown as 1 on the plot) being the wettest.  Stations shaded in green indicate monthly precipitation above the 80th percentile, and stations shaded in brown indicate precipitation below the 20th percentile.

The period used for computing the anomalies, percentiles, and median is 1971-2000.  "CAMS" is an acronym for the "Climate Anomaly Monitoring System" in use at the Climate Prediction Center (CPC) at the US National Centers for Environmental Prediction (NCEP).