FVXX20 KNES 210041 VOLCANIC ASH ADVISORY ISSUED: 2005APR21/0040Z VAAC: WASHINGTON VOLCANO: ANATAHAN 0804-20 LOCATION: N1621E14540 AREA: MARIANA.ISLANDS SUMMIT ELEVATION: 2585 FT (788 M) ADVISORY NUMBER: 2005/183 INFORMATION SOURCE: GFS MODEL WINDS. GOES-9. ERUPTION DETAILS: CONTINUOUS ASH AND STEAM EMISSIONS. OBS ASH DATE/TIME: 21/0002Z OBS ASH CLOUD: ASH NOT IDENTIFIABLE FROM SATELLITE DATA. WINDS SFC/FL100 MOVING TO W 10-15 KNOTS. FCST ASH CLOUD +6H: 21/0645Z SFC/FL100 15NM WIDE LINE BETWEEN N1619E14519 - N1620E14535. FCST ASH CLOUD +12H: 21/1245Z SFC/FL100 15NM WIDE LINE BETWEEN N1619E14517 - N1620E14536. FCST ASH CLOUD +18H: NOT AVBL REMARKS: LOW LEVEL WEATHER CLOUDS CONTINUE TO DEVELOP TO THE EAST AND WEST OF THE ISLAND AND MOVE TO THE WEST AT 10-15Z. THERE MAY BE SOME MIXING WITH ASH BUT IT IS NOT CERTAIN DUE TO DESCREPANCIES BETWEEN THE VISIBLE AND MULTISPECTRAL IMAGERY WHICH DOES NOT SHOW A HOTSPOT. MULTISPECTRAL IMAGERY SHOWS PLUME LIKE FEATURE TO THE WEST OF THE SUMMIT THAT GETS BRIGHTER AS IT MOVES AWAY AND THUS APPEARS TO BE DEVELOPING CLOUDS. ...BALDWIN NEXT ADVISORY: WILL BE ISSUED BY 2005APR21/0645Z NNNN