APCEDI ALERT Sri Lanka-BOBW, TD 2, #2, 2006:Tropical Depression threatening to become cyclone near Andaman Islands

The Joint Typhoon Warning Center (JTWC) and the Sri Lanka and India Departments of Meteorology are continuing to provide guidance on a tropical depression that is strengthening near the Andaman Islands.

In what continues to be a fairly constant wave of activity in the Bay of Bengal, this tropical depression, located about 100 km to the southwest of Port Blair in the Andaman Islands, is now threatening to form into a significant cyclone. JTWC has issued a Tropical Cyclone Formation Alert for development of this system into a significant tropical cyclone in the next 24 hours. Movement of this system is toward the northwest.

Given the heavy flooding in Tamil Nadu from Cyclone Baaz, and the saturation of soils throughout much of Southeast India and Sri Lanka from subsequent tropical waves, this system has the potential to cause significant additional flooding. Chennai's 2 main rivers, the Adyar and Cooum have topped their banks in many areas throughout the city and in rural areas. 75,000 residents have been evacuated to 140 relief shelters in and around the city. Thus any additional heavy rain in and around Chennai in the next 2-4 days has the potential to make the situation worse. More details on the news of the flooding in Chennai can be found in The Hindu

Authorities, aid workers and residents should maintain vigilance with this system. Maritime interests including fisherfolk in both countries should beware of continuing rough seas in the wake of these repeated disturbances.

FROM JOINT TYPHOON WARNING CENTER
http://www.npmoc.navy.mil/jtwc.html

WTIO21 PGTW 051430
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE FORMATION ALERT 051421Z DEC 05// RMKS/

1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 110 NM EITHER SIDE OF A LINE FROM 10.4N 91.3E TO 12.1N 88.0E WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO BE 30 TO 35 KNOTS. METSAT IMAGERY AT 051200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 10.6N 90.9E. THE SYSTEM IS MOVING NORTHWESTWARD AT 05 KNOTS.

2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 9.7N 91.4E, IS NOW LOCATED NEAR 10.6N 90.9E, APPROXIMATELY 640 NM EAST OF MADRAS, INDIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES AN INCREASE IN DEEP CONVECTION OVER THE LOW LEVEL CIRCULATION CENTER (LLCC) IN THE EASTERN BAY OF BENGAL. A 051233Z
SSMI PASS ALSO DEPICTS AN IMPROVED LLCC. UPPER LEVEL ANALYSIS INDICATES THAT THE CIRCULATION REMAINS IN A REGION OF LOW TO MODERATE VERTICAL WIND SHEAR WITH FAVORABLE POLEWARD DIVERGENCE. MAXIMUM
SUSTAINED WINDS ARE ESTIMATED AT 30 TO 35 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. DUE TO AN INCREASE IN CONVECTION OVER AN IMPROVING LLCC, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO GOOD.

3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 061430Z.//

NNNN

SRI LANKA DEPARTMENT OF METEOROLOGY
http://www.meteo.slt.lk/index.html

Same advice as previous report, to be updated shortly

INDIAN DEPARTMENT OF METEOROLOGY
http://www.imd.gov.in/

The low pressure area over south Andaman Sea persists and is now well marked. The system is likely to concentrate into a depression. Associated upper air cyclonic circulation extends upto 3.1 km a.s.l. As the system is likely to move west-northwestwards, the rainfall activity over south Peninsula is likely to increase from 8th December.

WARNINGS

ISOLATED HEAVY RAINFALL LIKELY OVER ANDAMAN & NICOBAR ISLANDS.
Rainfall activity is likely to increase over south Peninsula with possibility of isolated heavy to very heavy falls.


APCEDI will continue to monitor this system as it moves toward India and Sri Lanka.

While APCEDI does not normally monitor cyclones in the Bay of Bengal, given AFAP's tsunami relief effort and that of many agencies in the region, APCEDI will continue to bring reports from this region, as warranted, for the next year or longer if needed.

Kevin Vang
APCEDI Coordinator
http://www.afap.org/apcedi/

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