FVXX21 KWBC 181854 VOLCANIC ASH ADVISORY ISSUED: 2004JUL18/1854Z VAAC: WASHINGTON VOLCANO: ANATAHAN 0804-20 LOCATION: N1621E14540 AREA: MARIANA.ISLANDS SUMMIT ELEVATION: 2585 FT (788 M) ADVISORY NUMBER: 2004/ INFORMATION SOURCE: GFS MODEL WINDS FORECAST. GOES-9 IMAGERY. ERUPTION DETAILS: OCCASIONAL VENTING OF GASES AND ASH OBS ASH DATE/TIME: 18/1802Z OBS ASH CLOUD: ASH NOT IDENTIFIABLE FROM SATELLITE DATA. WINDS SFC/FL050 MOVING TO W 15 KNOTS. FCST ASH CLOUD +6H: NOT AVBL FCST ASH CLOUD +12H: NOT AVBL FCST ASH CLOUD +18H: NOT AVBL REMARKS: IT IS DIFFICULT TO DETECT LOW LEVEL ASH IN INFRARED IMAGERY. ...KARST NEXT ADVISORY: WILL BE ISSUED BY 2004JUL19/0100Z NNNN