San Fernando Valley home prices surged 39 percent in May, driven by lack of homes for sale in the area. The median hit $520,000, the highest since February 2008. Just 1,142 homes were on the market last month, which amounts to a 1.3-month supply, according to the Southland Regional Association of Realtors, a Van Nuys trade group. “The market is working in the sense that pent-up demand for housing and a severely limited inventory combined to push prices higher,” said Sharon Barron, president of the association, in a statement. Home prices in the Santa Clarita Valley rose 17 percent from the previous month. Prices rose to $420,500, up 16.8 percent from the same month a year earlier. Realtors in the area say it may be quite awhile before supply and demand comes back to normal levels. “The long-term outlook is excellent, although it will take a couple years for the inventory to come back to what we’re used to,” said Bob Khalsa, president of the trade association’s Santa Clarita Valley division, in a statement. “In the short term, the market is getting healthier. We just have to ride out the very low supply of homes listed for sale.”