FVXX21 KWBC 241410 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 1410 UTC 24 OCTOBER 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-025 ECUADOR 1.47S 78.44W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 INFRARED AND MULTISPECTRAL IMAGERY ...GEOPHYSICAL INSTITUTE. UPPER AIR SOUNDING NEAR THE VOLCANO. . ERUPTION DETAILS: CONTINUOUS VENTING OF ASH AND STEAM. . DETAILS OF ASH: THE LATEST GOES-8 SATELLITE IMAGERY THROUGH 1315 UTC SUGGESTS A POSSIBLE NARROW ASH OR STEAM PLUME LEAVING THE SUMMIT AND MOVING TO THE SOUTHWEST. THERE REMAINS AN ABUNDANCE OF MULTILAYERED CLOUDS AROUND THE VOLCANO WHICH IS MAKING IT DIFFICULT TO DISTINGUISH ANY POSSIBLE ASH. UPPER-AIR DATA AND SATELLITE IMAGERY INDICATE THAT THIS PLUME IS AT ABOUT FL240. THE GEOPHYSICAL INSTITUTE CONTINUES TO REPORT THAT SEISMIC ACTIVITY REMAINS HIGH AND IT IS LIKELY THAT THE VOLCANO WILL CONTINUE TO VENT ASH AND GASES. CAUTION IS STRONGLY ADVISED. . TRAJECTORY: SATELLITE IMAGERY SHOWS THIS NARROW PLUME MOVING SOUTHWEST AT 10 TO 15 KNOTS AND UPPER-AIR DATA CONFIRMS THIS MOTION. . 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/) . OUTLOOK: SEE SIGMETS. . THE NEXT STATEMENT WILL BE ISSUED AROUND 24/2000 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . ORRISON . NNNN