Meteorological (weather) refers to the level of dryness of an area or less precipitation than others. It is the most significant cause of drought across the planet.
Ocean currents (Atmospheric and oceanic circulation) can cause droughts because they control much of the climate patterns of an area (e.g. the Gulf Stream causes a warmer temperature to the UK) and a change can have a large impact, such as a desert or a drought area.
Jet streams can cause low pressure areas (rain) to be diverted from their path so an area might get less water than an other and can cause an area to get one rainy season and an other to become drought out a very small precipitation.