FVXX20 KWBC 161220 VOLCANIC ASH ADVISORY ISSUED 1220 UTC 16 SEP 2000 BY THE WASHINGTON VAAC . SOUFRIERE HILLS 00-238 WEST INDIES 1643N 6211W . BACKGROUND: SOUFRIERE HILLS MONTSERRAT (1600-05) SUMMIT HEIGHT 3000 FT (915M) . SOURCES OF INFORMATION: GOES-8 VISIBLE...INFRARED..AND MULTISPECTRAL IMAGERY. 16/1200 UTC FORECAST UPPER WINDS FROM THE 16/0600 UTC AVIATION MODEL. . ERUPTION DETAILS: CONTINUED ROCKFALLS AND SMALL PYROCLASTIC FLOWS. . DETAILS OF ASH CLOUD: GOES-8 IMAGERY THROUGH 1145 UTC DOES NOT INDICATE THE PRESENCE OF ASH DUE TO BROKEN MID AND HIGH LEVEL CLOUDS PARTIALLY OBSCURING THE VIEW NEAR AND AROUND THE VOLCANO. LOW LEVEL ASH BELOW FL100 WOULD BE DIFFICULT TO DETECT AT THIS TIME. WE WILL KEEP THE ADVISORY ALIVE UNTIL THERE IS DEFINITIVE EVIDENCE TO WARRANT AND END ADVISORY. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST ANY ASH AT OR BELOW FL100 TO MOVE SOUTHWEST AT 5 TO 10 KNOTS. . OUTLOOK: SEE SIGMETS. . THE NEXT ADVISORY WILL BE ISSUED BY 16/1830 UTC. . REAL TIME SATELLITE IMAGERY AND VOLCANIC ASH ADVISORIES 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/) . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . HUGHES . NNNN