The regional government called an emergency meeting and authorities said rescue workers and military units were heading to the area to help.
A British couple were among ten people killed as flash flooding turned streets in Mallorca into torrents and left hundreds homeless.
"It all happened in less than 10 minutes", an unidentified witness with wet clothes told the public broadcaster TVE. The flooding also affected phone communications and forced the closure of at least seven major roads.
Some parts of the island received up to 23 centimeters (nine inches) of rainfall in around four hours on Tuesday evening, national weather authorities reported.
The thunderstorms are still circulating in the region and further torrential rain is expected on Wednesday and Thursday, with southern France and northwest Italy being most at risk of flooding.
Spain's meteorological office said the neighbouring islands of Ibiza and Formentera were now on high alert as the rain and storms moved there.
Stevie Nicks, Def Leppard early favorites for Rock Hall of Fame
Rounding out the nominees are Def Leppard , Devo , MC5, John Prine , The Cure , Roxy Music , The Zombies , and Todd Rundgren . Artists must have released their first commercial recording at least 25 years prior to the year of nomination to be eligible.
Hubble Space Telescope in 'safe mode' after technical snag
Hubble entered safe mode after one of the three gyroscopes (gyros) actively being used to point and steady the telescope failed. Hubble's successor, James Webb, the large space American telescope after successive delays, will not be launched before 2021.
Young people and mental health in a changing world
"We gave an overview of what mental health actually is, looking at the stigma around mental health and challenging that". The tips below are universal principles created to support a diverse range of people across a range of workplaces.