8Hackers from China breached the federal weather network recently, forcing cybersecurity teams to seal off data vital to disaster planning, aviation, shipping and scores of other crucial uses, officials said. The intrusion occurred in late September but officials gave no indication that they had a problem until Oct. 20, according to three people familiar with the hack and the subsequent reaction by the National Oceanic and Atmospheric Administration or NOAA, which includes the National Weather Service. Even then, NOAA did not say its systems were compromised. Officials also said that the agency did not notify the proper authorities when it learned of the attack. More