FVXX21 KWBC 1845 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 1845 UTC 24 May 1999 BY THE WASHINGTON VAAC . POPOCATEPETL 99-070 MEXICO 19.02N 98.62W . BACKGROUND: POPOCATEPETL MEXICO (1401-09) SUMMIT HEIGHT 17930 FT (5465 M) . SOURCES OF INFORMATION: CENEPRED..PILOT REPORT...1200 UTC UPPER AIR DATA FROM MEXICO CITY...GOES 8 VISIBLE AND MULTISPECTRAL IMAGERY . ERUPTION DETAILS: ERUPTION AROUND 24/1750 UTC. . DETAILS OF ASH CLOUD: VISIBLE AND MULTISPECTRAL SATELLITE IMAGERY THROUGH 1815 UTC DID NOT INDICATE ANY ASH CLOUD UNDER CLEAR SKIES. THE MEXICAN VOLCANO OBSERVATORY (CENEPRED) AND A PILOT REPORT INDICATED ASH TOPS BETWEEN FL210 AND FL250. . TRAJECTORY: ANY ASH BETWEEN FL180 AND FL240 WOULD MOVE TOWARDS THE SOUTHWEST AT 20 KNOTS WHILE ASH BETWEEN FL240 AND FL250 WOULD MOVE SOUTH SOUTHWEST AT 5 KNOTS. . 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 AROUND 25/0100 UTC . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN