The FAA has issued a NOTAM warning of widespread GPS outages starting Tuesday throughout the Southwest and especially southern California. China Lake Naval Weapons Center will be testing something that can disrupt GPS signals over a wide area. The NOTAM goes on to say the tests will potentially knock out all GPS-reliant services including WAAS, GBAS, and ADS-B. Dates for the disruption are June 9, 21, 23, 28 and 30. For more information follow this link.