* - The location of Lubbock's rainfall observations has changed several times since 1911.
** - In some cases, precipitation amounts less than a few hundredths of an inch broke the string of dry days. A criterion of a more significant precipitation total (such as 0.25" for example) might be useful.
*** - The ENSO MEI, or El Nino/Southern Oscillation Multivariate ENSO Index is a convenient way to characterize the ENSO phase. The index takes into account six atmospheric variables observed over the tropical Pacific Ocean. Values typically range from +2.0 to -2.0. A positive value signifies the El Nino, or warm phase and a negative value signifies La Nina or cool phase. ENSO phases are know to have long-term climate effects in the Southern United States. For example, studies have shown that El Nino winters are statistically warmer and wetter than average while La Nina winters are cooler. For more information on ENSO, please visit the website http://www.cdc.noaa.gov/ENSO/