Gregory's Server
2. Not just the past days, but the whole summer the temperatures in the Mediterranean were warmer than average. Due to the extra evaporation, this gives a bunch of humid air hanging around above the mediterranean.
You can find the temperature anomalies for the Mediterranean Sea on this website : https://www.ceam.es/ceamet/SST/SST-anomaly.html
3. A low pressure area is circling in front of the coast of Portugal, and that circulation drags all this moist air over the mountains surrounding Valencia. In the satellite images you can see a plume of very cold and wet air rise right above Valencia. This is caused by the wet mass of air above the mediterranean that is dragged over the mountains by the circulation west of Portugal. Quickly rising air cools down, and this causes the intense rains.