WASHINGTON (MarketWatch)-- An early gauge of U.S. manufacturing jumped to its highest level in almost four years in February from the prior month, Markit reported Thursday. The U.S. flash purchasing managers’ index rose to 56.7 in February, up from January level of 53.7, which was a three-month low. This is the fastest overall improvement in conditions since May 2010. Readings above 50 indicate expansion, with higher readings signaling faster expansions. Chris Williamson, chief economist at Markit, said production has rebounded from a weather-related slowdown seen in January. He noted that there was the largest rise in backlogs of work seen since prior to the financial crisis, as well as a steep fall in inventories. "Both point to ongoing growth of production and hiring in March," Williamson said.