FVXX21 KWBC 201700 VOLCANIC ASH ADVISORY ISSUED 1700 UTC 20 JUL 2000 BY THE WASHINGTON VAAC . TUNGURAHUA 00-847 ECUADOR 0128S 7826W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 VISIBLE..INFRARED AND MULTISPECTRAL IMAGERY. WINDS FORECAST FROM THE AVIATION MODEL. GEOPHYSICAL INSTITUTE REPORT. . ERUPTION DETAILS: GASES WITH OCCASIONAL ASH EMISSIONS. . DETAILS OF ASH: ASH WAS NOT SEEN IN THE SATELLITE IMAGERY THROUGH 20/1615 UTC ALTHOUGH THERE ARE EXTENSIVE CLOUDS IN THE AREA. THE GEOPHYSICAL INSTITUTE REPORTED ASH OVER THE SUMMIT AT 20/1440 UTC TO FL250 MOVING WEST. TRAJECTORY: ASH FROM THE SUMMIT TO FL250 WOULD MOVE TOWARDS THE WEST AT 10-20 KNOTS. . OUTLOOK: SEE SIGMETS. . THE NEXT MESSAGE WILL BE ISSUED BY 20/2300 UTC. . REAL TIME SATELLITE IMAGERY ALONG WITH THIS AND OTHER 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. . WALTER . NNNN