FVXX21 KWBC 231805 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 1805 UTC 23 MAR 1999 BY THE WASHINGTON VAAC . POPOCATEPETL 99-052 MEXICO 19.02N 98.62W . BACKGROUND: POPOCATEPETL MEXICO (1401-09) SUMMIT HEIGHT 17930 FT (5465 M) . SOURCES OF INFORMATION: MEXICO CITY MWO AND CENAPRED . ERUPTION DETAILS: ERUPTED AT APPROXIMATELY 23/1635 UTC . DETAILS OF ASH CLOUD: WE HAVE NOT BEEN ABLE TO DETECT ANY ASH IN GOES-8 VISIBLE INFRARED OR MULTISPECTRAL SATELLITE IMAGERY. HOWEVER CENAPRED REPORTS THAT VOLCANIC ASH IS PRESENT BETWEEN FL180 AND FL200 5NMI TO THE EAST OF THE VOLCANO. . TRAJECTORY: EAST AT 20 TO 25 KNOTS BASED ON MEXICO CITY UPPER-AIR SOUNDING. . THIS AND OTHER VOLCANIC ASH ADVISORY STATEMENTS OFTEN ACCOMPANIED BY A MAP DEPICTING ASH LOCATION ARE AVAILABLE AT INTERNET URL ADDRESS www.ssd.noaa.gov/VAAC/messages.html (all lower case except /VAAC/) . OUTLOOK: SEE SIGMETS. . THE NEXT MESSAGE WILL BE ISSUED BY 24/0000 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN