FVXX21 KWBC 211115 VOLCANIC ASH ADVISORY ISSUED 1115 UTC 21 NOV 2000 BY THE WASHINGTON VAAC . POPOCATEPETL 00-122 MEXICO 1901N 9837W . BACKGROUND: POPOCATEPETL MEXICO (1401-09) SUMMIT HEIGHT 17930 FT (5465 M) . SOURCES OF INFORMATION: GOES-8 INFRARED AND MULTISPECTRAL SATELLITE IMAGERY. MEXICO CITY METEOROLOGICAL WATCH OFFICE. 21/0000 UTC MEXICO CITY UPPER AIR SOUNDING. . ERUPTION DETAILS: STEAM AND POSSIBLE ASH EXHALATIONS AT 1019 UTC AND 1021 UTC AND 1100 UTC. . DETAILS OF ASH CLOUD: THE MEXICO CITY MWO REPORTED THREE MODERATE EXHALATIONS OF THE VOLCANO BUT COULD NOT CONFIRM WHETHER THERE WAS ASH PRESENT DUE TO CLOUDS AND DARKNESS. SATELLITE IMAGERY THROUGH 21/1045 UTC SHOWS EXTENSIVE CLOUDS OVER THE AREA MAKING ASH DETECTION DIFFICULT. THE MEXICO CITY MWO ESTIMATED THE HEIGHT OF THE POSSIBLE ASH AND STEAM BETWEEN FL170 AND FL220. . TRAJECTORY: THE UPPER AIR SOUNDING SUGGESTS THAT ANY ASH PRESENT FROM SUMMIT LEVEL TO FL220 WOULD MOVE TOWARD THE WEST AND NORTHWEST AT ABOUT 5 TO 15 KNOTS. . OUTLOOK: SEE SIGMETS . THE NEXT MESSAGE WILL BE ISSUED BY 21/1715 UTC. . REAL TIME SATELLITE IMAGERY AND 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. . CLARK . NNNN