FVXX21 KWBC 250900 VOLCANIC ASH ADVISORY ISSUED 0900 UTC 25 AUG 2000 BY THE WASHINGTON VAAC . TUNGURAHUA 00-0994 ECUADOR 0128S 7826W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 INFRARED AND MULTISPECTRAL IMAGERY. WIND FORECAST FROM THE AVIATION MODEL. . ERUPTION DETAILS: GAS AND OCCASIONAL ASH EMISSIONS. . DETAILS OF ASH: SATELLITE IMAGERY THROUGH 25/0815 UTC SHOWS EXTENSIVE LOW AND MID LEVEL CLOUDS IN THE VICINITY OF THE VOLCANO MAKING IT DIFFICULT TO DETECT ANY ASH. THE GEOPHYSICAL INSTITUTE REPORTED ASH OVER THE VOLCANO AT 25/0339 UTC. . TRAJECTORY: ANY ASH AT SUMMIT LEVEL WILL MOVE TOWARDS THE WEST AT 20 KNOTS. . OUTLOOK: SEE SIGMETS. . THE NEXT ADVISORY WILL BE ISSUED BY 25/1500 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