East Coast Low. An intense low pressure systems that often develop very rapidly (sometimes explosively) in the Tasman Sea close to (within 5° usually) the east coast of Australia. It often brings gale-force or storm-force winds, phenomenal seas and localised heavy rainfall, and may persist for a few days. ECL's are responsible for many of the extreme rainfall maxima along the NSW coastline. ECL's are generally "cut off" from the usual westerly airflow.