FVXX22 KWBC 040830 VOLCANIC ASH ADVISORY STATEMENT ISSUED 0830 UTC 04 DEC 1999 BY THE WASHINGTON VAAC . SAN CRISTOBAL 99-012 NICARAGUA 12.7N 87.0W . BACKGROUND: SAN CRISTOBAL NICARAGUA (1404-02) SUMMIT HEIGHT 5725 FT (1745 M) . SOURCES OF INFORMATION: GOES-8 INFRARED AND MULTISPECTRAL IMAGERY...0000 UTC AVIATION MODEL UPPER-AIR SOUNDING DATA . ERUPTION DETAILS: ASH AND STEAM VENTING...BEGINNING AROUND 1630 UTC . DETAILS OF ASH CLOUD: SATELLITE IMAGERY THROUGH 04/0745 UTC SHOWS NO ASH SIGNATURES BUT EARLIER THE PLUME WAS ONLY OBSERVABLE IN VISIBLE IMAGERY . TRAJECTORY: WEST AT 10 TO 15 KNOTS. . 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 www.ssd.noaa.gov/VAAC/washington.html (all lower case except /VAAC/) . OUTLOOK: SEE LATEST 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 04/1430 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN