After inspection of the hydro-meteorology, it seems that there will be considerable precipitation over the next 72 hours, but not of sufficient magnitude to cause significant flooding.
The midnight Gibraltar sounding shows deep instability but not a huge amount of moisture. So expect to see thunderstorms, mostly embedded in a widespread cloud mass, today. These thunderstorms should be particularly vigorous this afternoon. These storms could drop localized heavy amounts of rain. The area with the highest threat appears to be the high terrain of the Alcornocales (Cadiz/Malaga province border) and the Sierra Norte (north of Huelva/Seville/Cordoba), Algeciras and Gibraltar.
Tomorrow should be drier, but with some showers, especially in the afternoon. Perhaps the biggest dose of rain will come with an organized low pressure system arriving from the southwest early Monday morning. We shall see if this storm brings a significant rise in the rivers and reservoirs.
The good news for Seville Fair attendees is that most of the rain should be gone by the "alumbrao" on Monday. Stay tuned for changes, however, as the Feria is known for its wet weather!