FVXX21 KWBC 071730 VOLCANIC ASH ADVISORY ISSUED 1730 UTC 07 JUL 2000 BY THE WASHINGTON VAAC . TUNGURAHUA 00-794 ECUADOR 0128S 7826W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 VISIBLE ... INFRARED AND MULTISPECTRAL IMAGERY. SIX HOUR WIND FORECAST FROM THE 07/1200 UTC AVIATION MODEL. SIGMET FROM GUAYAQUIL METEOROLOGICAL WATCH OFFICE. . ERUPTION DETAILS: GAS AND OCCASIONAL ASH EMISSIONS. . DETAILS OF ASH: ASH CANNOT BE DISCERNED IN THE SATELLITE IMAGERY THROUGH 07/1645 UTC DUE TO BROKEN CLOUDS IN THE VICINITY OF THE VOLCANO. HOWEVER A WEAK HOT SPOT WAS SEEN AT 1645 UTC. AT 07/1355 UTC A PILOT REPORTED ASH TO FL270. AT 1620 UTC THE GEOPHYSICAL INSTITUTE REPORTED POSSIBLE ASH OVER THE VOLCANO AT UNKNOWN HEIGHT. . TRAJECTORY: ANY ASH NEAR THE SUMMIT WOULD MOVE TOWARDS THE WEST AT ABOUT 15 KNOTS. FROM THE SUMMIT TO FL270 WINDS BECOME LIGHT AND VARIABLE. . OUTLOOK: SEE SIGMETS. . THE NEXT MESSAGE WILL BE ISSUED BY 07/2330 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. . NNNN