Monitoring water vapour with GNSS during a heavy rainfall event in the Spanish Mediterranean area

[EN] The Spanish Mediterranean area is periodically affected by torrential rainfall events during autumn. In September 2012, one of these episodes took place with up to 50 mm of rain in a 1-hour period and with more he results show a mean increase in IWV of around 30 kg/m2 occurring prior to heavy recipitation. They further revealed an increase of up to a 100% in IWV values in several GNSS stations available in the study area. Fluctuations in IWV fields correlate well with approaching frontal rainfall and a combined rise in IWV and a drop in atmospheric pressure may well be used as a pre-cursor to heavy precipitation.