dana

A word increasingly integrated into meteorological language, expressed interchangeably in lowercase or uppercase letters (DANA), although the latter form -with which the term began to be used- is progressively being replaced by the former, as shown in this entry. It is the acronym for 'isolated depression at high levels'; an expression that meteorologists from the former National Institute of Meteorology (INM) -currently AEMET- began using in the mid-1980s to counteract the abusive use that was already being made of the expression 'cold drop'. In this latter way, the population began to identify, particularly in the Mediterranean area, any episode of heavy rain in the area, regardless of whether or not there was a dana. It is not necessary for a pocket of cold air aloft, cut off from the general flow, to exist for torrential rain to fall, nor does its presence guarantee heavy rain in all cases. The term dana was chosen to honor the memory of meteorologist Francisco García Dana (1924-1984), who served as head of the INM Prediction Center from 1979 until 1984, the year he passed away. A dana is an isolated low pressure system aloft, reflected at the 300 and 500 hPa isobaric levels, but not at the surface. Being cut off from the general westerlies, it evolves independently, with its own lifecycle. Danas tend to be fairly stationary, sometimes displaying retrograde motion, opposite to that of typical low-pressure systems.