FVXX21 KWBC 291850
VOLCANIC ASH ADVISORY STATEMENT
ISSUED 1850 UTC 29 DEC 1999 BY THE WASHINGTON VAAC 
.
TUNGURAHUA 99-311         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 IN QUITO...UPPER-AIR SOUNDING
DATA...GUAYAQUIL MWO SIGMET...AIRCRAFT REPORT...
.
ERUPTION DETAILS: INTERMITTENT ASH AND STEAM EMISSIONS...  
.
DETAILS OF ASH: SATELLITE IMAGERY THROUGH 29/1815 UTC DOES NOT SHOW
ANY ASH OVER OR ADJACENT TO THE SUMMIT. HOWEVER THERE IS AN
ABUNDANCE OF SHOWER AND THUNDERSTORM ACTIVITY JUST EAST OF THE
SUMMIT WHICH IS SHROUDING THE REGION IN MULTILAYERED CLOUDINESS.
THIS IS MAKING IT VERY TOUGH TO SEE WHAT IS OCCURRING AT THE SUMMIT
LEVEL. IT IS POSSIBLE IN THIS SITUATION FOR ASH TO BE EMBEDDED
WITHIN THE CLOUD DECKS AND GO UNDETECTED. SMALL ERUPTIONS HAVE BEEN
REPORTED ON A DAILY BASIS WHICH HAVE PRODUCED ASH AND SO EXTREME
CAUTION IS SUGGESTED. ASH AND STEAM SEVERAL HOURS AGO WAS NOTED TO
BE REACHING FL230.
.
TRAJECTORY: ASH AND STEAM REACHING FL230 SHOULD MOVE SOUTHWEST AT
ABOUT 10 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  
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 30/0100 UTC.
.
PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS.
.
ORRISON
.
NNNN