FVXX21 KWBC 252300 VOLCANIC ASH ADVISORY STATEMENT ISSUED 2300 UTC 25 FEB 2000 BY THE WASHINGTON VAAC . TUNGURAHUA 00-239 ECUADOR 0128S 7826W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 INFRARED MULTISPECTRAL AND VISIBLE IMAGERY...GEOPHYSICAL INSTITUTE...1200 UTC AVIATION MODEL UPPER AIR SOUNDING DATA. . ERUPTION DETAILS: EXPLOSIVE ERUPTION AT 25/1630 UTC . DETAILS OF ASH: THE GEOPHYSICAL INSTITUTE REPORTED AN EXPLOSIVE ERUPTION AT 1630 UTC BASED ON SEISMIC ACTIVITY. AT 2100 UTC RIOBAMBA/CHIMBORAZO REPORTED ASH MOVING WEST-SOUTHWEST AT FL170. NO ASH COULD BE DISCERNED IN GOES-8 SATELLITE IMAGERY AT 2045 UTC BECAUSE OF EXTENSIVE CLOUDINESS IN THE VICINITY. . TRAJECTORY: ANY ASH FROM THE SUMMIT TO FL280 IS FORECASTED TO MOVE WESTWARD AT 10 TO 15 KNOTS. . OUTLOOK: SEE SIGMETS. . THE NEXT STATEMENT WILL BE ISSUED BY 26/0500 UTC. REAL TIME SATELLITE IMAGERY ALONG WITH THIS AND OTHER VOLCANIC ASH ADVISORY STATEMENTS 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. . BROWN . NNNN