U.S. home sales rebounded strongly in February, boosted by hefty gains in the South and West regions, but a chronic shortage of houses on the market remains an obstacle heading into the spring selling season. The National Association of Realtors said on Wednesday that existing home sales jumped 3.0 percent to a seasonally adjusted annual rate of 5.54 million units last month. That ended two straight months of declines. January’s sales pace was unrevised at 5.38 million units. “All signs point to a spring buying season of high prices and low inventory as any new construction that is added is snapped up quickly by buyers,” said Danielle Hale, chief economist for realtor.com.