They say it's the rain.Assessment - 19 May 2010 17:55According to radar and pilots’ observations, the plume has been slightly lower today than yesterday, at 5-6 km (18,000-20,000 ft). Southerly winds prevailed this morning over the volcano, turning to the southwest at 15-18 m/s. The plume drifted northwest early this morning, but then turned north-northeast, and its colour is gray or light gray. The number of lightning strikes has decreased.Ash has fallen in the south at Flúðir, FljótshlÃð and Rangárþing ytra. Ash has also fallen with rainfall in the north, in HúsavÃk and Skagafjörðyour, right before noon.Heavy rainfall caused swelling of Eyjafjallajökull rivers today. The rain, together with ash from an area of a few square kilometers, resulted in a mudslide in Svaðbæli river. Hydrologists from IMO, and a scientist from IES, gathered samples from the river and also from Skógar river. The discharge at the old bridge over Markarfljót river has not been greater since 15 April. The discharge at GÃgjökull is still low.The plume is up to 5-6 km and drifts to the north-northeast according to reconnaissance flight from the Icelandic Coast Guard this afternoon.The above is based on a status report issued collectively by the Icelandic Meteorological Office and the Institute of Earth Sciences at 17:00.