FVXX21 KWBC 241300 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 1300 UTC 24 DEC 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-288 ECUADOR 1.47S 78.44W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 VISIBLE INFRARED AND MULTISPECTRAL IMAGERY...GEOPHYSICAL INSTITUTE REPORT...0600 UTC AVIATION MODEL WIND FORECAST . ERUPTION DETAILS: INTERMITTENT ASH AND STEAM EMISSIONS . DETAILS OF ASH: NO ASH CAN BE SEEN IN SATELLITE IMAGERY THROUGH 24/1215 UTC POSSIBLY DUE TO THE WEATHER CLOUDS IN THE AREA. OCCASIONAL SMALL EXPLOSIONS THAT HAVE BEEN REPORTED BY THE GEOPHYSICAL INSTITUTE ON A DAILY BASIS HAVE BEEN TYPICALLY SENDING ASH AND STEAM TO BETWEEN FL180 AND FL230. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ANY ASH BETWEEN FL160 AND FL200 WOULD MOVE TO THE WEST OR NORTHWEST AT ABOUT 5 KNOTS. HIGHER LEVEL ASH WOULD MOVE MORE TO THE SOUTH OR SOUTHWEST AT UP TO 15 KTS. . 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. . EFFECTIVE JANUARY 3 2000 AT 0000 UTC... ALL REFERENCES TO LATITUDE AND LONGITUDE IN VOLCANIC ASH ADVISORY STATEMENTS WILL BE IN DEGREES AND MINUTES OF A DEGREE. EXAMPLE: 16.70N 62.20W WILL BE 1642N6212W . THE NEXT STATEMENT WILL BE ISSUED BY 24/1900 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . STREETT . NNNN