Precipitation

(data through 1/16/13)
Data Source(s): High Plains Regional Climate Center

Drier-than-average conditions have characterized the 2013 water year, which began on October 1, 2012 (Figures 2a–b). Precipitation in most of the Southwest was below 50 percent of average between October 1 and January 16. Only the far western border of Arizona and a sliver in northeastern New Mexico received above-average precipitation. In early December, however, several storms helped boost snowpack levels to near-average conditions in both states.

In the past 30 days, however, precipitation has essentially shut down in the Southwest. Most of Arizona and New Mexico have experienced less than 50 percent of average rain and snow between mid-December and mid-January (Figures 2c–d). Most winter storms with potential to affect the region have either been dry or have tracked to the north. The lone wet storm hit eastern and southeastern New Mexico on January 10 as the system dipped south into Mexico, skirting around most of Arizona, before migrating northeast into southeastern New Mexico and Texas.

Notes:

The water year begins on October 1 and ends on September 30 of the following year. As of October 1, 2012, we are in the 2013 water year. The water year is a more hydrologically sound measure of climate and hydrological activity than is the standard calendar year.

Average refers to the arithmetic mean of annual data from 1971–2000. Percent of average precipitation is calculated by taking the ratio of current to average precipitation and multiplying by 100.

The continuous color maps (Figures 2a, 2c) are derived by taking measurements at individual meteorological stations and mathematically interpolating (estimating) values between known data points. Interpolation procedures can cause aberrant values in data-sparse regions.

The dots in Figures 2b and 2d show data values for individual meteorological stations.