By Catarina Demony and Miguel Pereira LISBON (Reuters) -Soaring temperatures in Portugal forced authorities to place more than half the country on red alert on Tuesday and deploy hundreds of firefighters to combat blazes erupting in the central region in a heatwave that also swept across Spain. With temperatures above 40 degrees Celsius (104 Fahrenheit) in many parts, a major wildfire that started last week in the Santarem area north of Lisbon was reignited on Tuesday due to strong winds. Another blaze nearby caused the closure of the two main highways connecting Lisbon to the northern city of…