FVXX27 KNES 211357 VA ADVISORY DTG: 20170321/1357Z VAAC: WASHINGTON VOLCANO: USER MESSAGE PSN: XX AREA: XX RMK: THE 557TH WEATHER WING IS ISSUING THIS MESSAGE ON BEHALF OF THE WASHINGTON VAAC. 557 WW AND THE WASHINGTON VAAC ARE CONDUCTING A COORDINATED OPERATIONAL BACKUP TEST FROM 21/1400Z - 21/1430Z. PLEASE BE AWARE THAT 557 WW WILL ISSUE ANY NECESSARY VOLCANIC ASH ADVISORIES ON BEHALF OF THE WASHINGTON VAAC DURING THIS TIME FRAME.