Annual Precipitation Maps
|Year||Total Precipitation||Departure from Normal||Historical Ranking|
ESRI ArcView Ascii (*.asc) and Golden Software Surfer Grid (*.grd) files containing the data used in the images above are contained in a zip file. The *.zip file includes annual precipitation raster data from 1979 to 2011, and ranking and departure data from 2000 to 2011.
- Total precipitation maps present annual precipitation totals in inches.
- Departure from normal maps depict the difference between annual precipitation totals and the historical "normal". 2011 annual precipitation is compared with the 1981-2010 normal. 2003 through 2010 annual precipitation is compared with the 1971-2000 normal. Years prior to 2003 were compared with the 1961-1990 normal period.
- Historical ranking maps depict annual precipitation totals as they rank when compared to annual totals over the modern record. The values presented are percentiles. A ranking near zero indicates the year was drier than any found during the period of record. A ranking near 100 designates that the year was wetter than any found on record. A ranking of 50 is equivalent to the "median", a measure of central tendency.