FVXX23 KWBC 090420 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 0420 UTC 09 NOV 1999 BY THE WASHINGTON VAAC . SOUFRIERE HILLS 99-255 WEST INDIES 16.7N 62.2W . BACKGROUND: SOUFRIERE HILLS MONTSERRAT (1600-05) SUMMIT HEIGHT 3000 FT (915 M) . SOURCES OF INFORMATION: MONTSERRAT VOLCANO OBSERVATORY...GOES-8 INFRARED AND MULTISPECTRAL SATELLITE IMAGERY...12 UTC AVIATION MODEL WIND DATA...00 UTC GUADELOUPE RADIOSONDE . ERUPTION DETAILS: ERUPTION OCCURRED AT 08/2030 UTC. . DETAILS OF ASH CLOUD: NO ASH IS SEEN IN SATELLITE IMAGERY THROUGH 09/0345 UTC. THE ASH CLOUD PREVIOUSLY OBSERVED NORTH AND EAST AND WEST OF MONTSERRAT HAS BECOME TOO DIFFUSE TO DISCERN IN IMAGERY. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ANY ASH BETWEEN FL050 AND FL100 WILL MOVE TO THE NORTH NORTHWEST AT LESS THAN 10 KNOTS. ANY ASH BETWEEN FL150 AND FL250 WILL MOVE TOWARD THE EAST AT 10 TO 15 KNOTS. . REAL TIME SATELLITE IMAGERY ALONG WITH THIS AND OTHER VOLCANIC ASH ADVISORY STATEMENTS OFTEN ACCOMPANIED BY A MAP DEPICTING ASH LOCATION ARE AVAILABLE AT INTERNET URL ADDRESS http://www.ssd.noaa.gov/VAAC/washington.html (all lower case except /VAAC/) . OUTLOOK: SEE SIGMETS AND VAFTAD. . THE NEXT MESSAGE WILL BE ISSUED BY 09/1030 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN