FVXX21 KWBC 151730 VOLCANIC ASH ADVISORY ISSUED 1730 UTC 15 SEP 2000 BY THE WASHINGTON VAAC . TUNGURAHUA 00-1081 ECUADOR 0128S 7826W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: VISIBLE AND INFRARED AND MULTISPECTRAL SATELLITE IMAGERY. WINDS FORECAST FROM THE AVIATION MODEL. GEOPHYSICAL INSTITUTE REPORT. . ERUPTION DETAILS: OCCASIONAL STEAM AND ASH EMISSIONS. . DETAILS OF ASH: SATELLITE IMAGERY THROUGH 15/1645 UTC SHOWS LOW AND MID LEVEL CLOUDINESS IN THE VICINITY OF THE VOLCANO MAKING IT DIFFICULT TO DETECT ANY ASH. THE VOLCANO REMAINS UNSTABLE AND MAY ERUPT AT ANY TIME. . TRAJECTORY: ANY ASH IN THE VICINITY OF THE SUMMIT MAY MOVE WESTWARD AT AROUND 20 KNOTS. . OUTLOOK: SEE SIGMETS. . THE NEXT MESSAGE WILL BE ISSUED BY 15/2330 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. . KARST . . NNNN