- Total precipitation maps depict annual precipitation totals in inches.
- Departure from normal maps depict the difference between annual precipitation totals and the
historical "normal ", a 1971-2000 average. The units are in inches. (1961-1990 normal period used before 2002).
- 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.
