WORLD METEOROLOGICAL ORGANIZATION FOR PARTICIPANTS ONLY
AND
ECONOMIC AND SOCIAL COMMISSION WRD/PTC.39/Doc. 3.2(2), ADD. 1
FOR ASIA AND THE PACIFIC (05.III 2012)
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WMO/ESCAP Panel on Tropical Cyclones
Thirty- ninth session
Nay Pyi Taw, Myanmar
5 to 9 March 2012 ENGLISH ONLY
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REVIEW OF THE 2011 CYCLONE SEASON
Reports of Members on the impact of tropical cyclones
(Submitted by Myanmar)
WRD/PTC.39/Doc. 3.2(2), ADD. 1, p. 2
Tropical Cyclone Activities in 2011 of Myanmar
Introduction
1. During 2011, the formation of total Low pressure Areas over the Bay of Bengal were (9) and (4) intensified to depressions and one became very severe cyclonic storm "THANE" and crossed India coast, near Chennai. One of them, the depression occurred in February which crossed to the northern coast of Sri Lanka is very singularity at 2011. The depression of October 17, gave heavy rain in Central Myanmar area caused flash flood.
Cyclone forecasting and warning activities
2. Myanmar Department of Meteorology and Hydrology (DMH) can use MTSAT imagery and grid data since 2011 January with the support of JICA. Through the data received from MTSAT ground receiving system it can be done cloud and wind analysis and 72 hours forecasts. On the other hand DMH can be used NWP products from neighboring NMHs and NOAA, JMA, BOM and UK Metoffice, etc.
3. Cyclone warning system is changed and more emphasized on Disaster Risk Reduction (DRR) since after Cyclone "Nargis". DMH early warning system for cyclone disaster use Color Code signal which are Yellow stage, Orange stage, Red emergency stage, Brown emergency stage and Green stage.
4. Cyclone warning and forecasts are distributed from top level and up to grass root level through printed matter, automatic answering machine, radio and television. The senior staffs of DMH write many articles for newspaper, weekly and monthly journals including TV-interviews for improving public awareness of natural disaster and meteorological processes. Besides, they give lectures in Disaster management training courses in all States and Regions of Myanmar.
Depressions and Cyclones occurrence during 2011
5. February 2nd – 6th Tropical Depression: According to the observation at 0600Z, a low pressure area has started formed in southwest Bay of Bengal. These LPA has intensified further into a Depression at 03022011 2300Z and centered at near northern coast of Sri Lanka and downgrade into LPA. On 6 February 2011, the low pressure area has become unimportant at 12:30 hour MST. Appendix (I).
6. Some Significant features of above Tropical Depression
(a) The duration of tropical depression is about 5 hours and
(b) The Tropical depression downgrade into low pressure area has been dissipated in the next 3 days.
7. June 17th – 19th Tropical Depression: according to the observation at (05:30) hour MST, the low pressure area has formed over North Bay of Bengal. It is further intensifying into a depression and has crossed near the west Bengal coast, India at 12:30 MST. The land depression still persisted at (05:30) hour MST on 18th June and dissipated at (05:30) hour MST on 19th June. Appendix (II)
8. Some Significant features of above tropical depression
(a) The tropical depression has formed after the onset of southwest monsoon in the whole country by 12 days.
(b) The tropical depression still persisted over the land as depression and then become unimportant.
9. September 20th - 23rd Tropical Depression: According to the observation at (17:30) hour MST, the low pressure area has formed over the Northwest Bay of Bengal on 20th September. It was further intensifying into a tropical depression at (14:30) hour MST on 22th September and centered at about (90) miles Southwest of Kolkatta, India. It is moved to Northwest direction and crossed the Northern Orissa Coast, India at (05:30) hour MST on 23rd September. Appendix (III)
10. Some significant features of above Tropical Depression
(a) The tropical depression has started to form and crossed the coast within (12) hours.
(b) The remnant of tropical depression caused the heavy rainfall in the coastal areas, Central and northwest part of Myanmar.
11. October 17th to 21st tropical Depression: According to the observation at (17:30) hour MST on 17th October, A low pressure area has formed over the East Central Bay which upgraded into depression within (43) hours. It was moved to the North Bay at (12:30) hour MST on 19th October. The depression started to move East-Northeast and crossed between Rakhine (Maungdaw) and Cox’s Bazar, Bangladesh at (20:00) hour MST and persisted as land depression. On 20th October, Firstly, the depression continued to move the Northeastwards and downgraded to LPA near the border of India and Myanmar (Chin State) at (05:30) hour MST and slowly moved to southerly direction and persisted over the East Central Bay and adjoining North Bay at (13:30) hour MST. It became unimportant at 05:30 hour MST on 21st October. Appendix (IV)
12. Some significant features of above tropical depression
(a) The depression has formed after the southwest monsoon withdrawal from the whole country by (10) days.
(b) After post monsoon period, the tropical depression generally form at about 18°N and move to the Northeast direction like this depression.
(c) The duration to become the tropical depression from the low pressure area is long compare to the life time of tropical depression. After crossing the coast, it still persisted as land depression. Under the influence of the tropical depression, the amount of rainfall between (6) inches to (8) inches were observed at Sagaing, Mandalay and Magway Regions, Chin and Rakhine States and caused Flash Floods. New ever recorded rainfall observed at some areas.
(d) "The low pressure area may be formed over the Bay of Bengal and intensified into a depression" is included in the monthly forecast issued by DMH for October 2011.
(e) America, India and Bangladesh of tropical cyclone forecasting center forecasted to move Northeast wards and intensify into cyclone. Especially, the issued warning included the strong wind and surge near the Northern Rakhine Coasts caused by tropical cyclone.
13. Details of the tropical depression condition
Date / Time (MST) / Place / Category17.10.2011 / 17:30 / East Central Bay of Bengal / LPA
18.10.2011 / 17:30 / East Central Bay of Bengal / LPA
19.10.2011 / 05:30 / North Bay of Bengal / LPA
19.10.2011 / 12:30 / About (160) miles South of Sittwe / Depression
19.10.2011 / 15:30 / About (35) miles West of Maungdaw (Rakhine) / Depression
19.10.2011 / 20:00 / Crossed between Maungdaw (Rakhine) Myanmar and Cox’s Bazar, Bangladesh / Depression
19.10.2011 / 22:30 / Land depression persists over Bangladesh / Land Depression
20.10.2011 / 05:30 / Move to Northeast and LPA persists between India and Myanmar (Chin State) / LPA
20.10.2011 / 13:30 / LPA move to southwards and East Central Bay and adjoining North Bay of Bengal / LPA
21.10.2011 / 05:30 / Become unimportant / LPA
Table - 1
14. December 24th to 30th Tropical Cyclone “THANE”
According to the observation at (18:30) hours MST on 24th December, the low pressure area has formed over the Southeast Bay of Bengal. It still persisted on 25th December and intensified into a depression and continued to move Northwest wards on 26th December. The depression was intensifying into a Cyclone “THANE” on 27th December and closely stationary on 28th December. On 29th December, the cyclone “THANE” was upgraded into a very severe cyclonic storm and continued to move the Westwards. On 30th December, it has crossed South of Chennai, South India.
15. Under the influence of Cyclone “THANE”, heavy rainfall experienced in Sagaing, Mandalay, Magway, Yangon and Bago Regions, Kachin, Shan, Chin, Rakhine and Kayah States.
16. Condition of a very cyclonic storm “THANE”
Date / Time (MST) / Place / Category24.12.2011 / 18:30 / Southeast Bay of Bengal / LPA
25.12.2011 / 05:30 / Southeast Bay of Bengal / LPA
25.12.2011 / 17:30 / South Bay and adjoining Central Bay of Bengal / LPA
26.12.0211 / 05:30 / About (540)miles Southeast of Chennai, India (about (550) miles Southwest of Coco-island, Myanmar) / Depression
26.12.2011 / 12:30 / About (490)miles Southeast of Chennai, India (about (560) miles Southwest of Coco-island, Myanmar) / Depression
26.12.2011 / 17:30 / About (480)miles Southeast of Chennai, India (about (560) miles Southwest of Coco-island, Myanmar) / Depression
27.12.2011 / 05:30 / About (480)miles Southeast of Chennai, India (about (560) miles Southwest of Coco-island, Myanmar) / Cyclone “THANE”
27.12.2011 / 12:30 / About (410)miles Southeast of Chennai, India (about (560) miles Southwest of Pathein and about (520) miles Southwest of Coco-island, Myanmar), Myanmar) / Cyclone “THANE”
27.12.2011 / 17:30 / About (380)miles Southeast of Chennai, India (about (710) miles Southwest of Pathein and about (560) miles Southwest of Coco-island, Myanmar), Myanmar) / Cyclone “THANE”
28.12.2011 / 05:30 / About (290)miles Southeast of Chennai, India / Cyclone “THANE”
28.12.2011 / 12:30 / About (280)miles Southeast of Chennai, India / Cyclone “THANE”
29.12.2011 / 05:30 / About (200)miles Southeast of Chennai, India / Very Cyclone Storm “THANE”
29.12.2011 / 12:30 / About (120)miles Southeast of Chennai, India / Very Cyclone Storm “THANE”
29.12.2011 / 17:30 / About (100)miles Southeast of Chennai, India / Very Cyclone Storm “THANE”
30.12.2011 / 05:30 / Crossing the south of Chennai, Tamil Nadu Coast, South India / Very Cyclone Storm “THANE”
30.12.2011 / 12:30 / Crossed the south of Chennai, Tamil Nadu Coast, South India / Very Cyclone Storm “THANE”
Conclusion
17. Tropical Cyclones over the Bay of Bengal in 2011 years
(a) Normally, no storm form in February during 1991 to 2010 as showed in Table (1). But February, 2011, Low Pressure Area formed over Southwest Bay was further intensified into a depression. The downgraded Low Pressure Area persisted over Southwest Bay adjoining Sri lanka Coast and then become unimportant.
(b) Shwebo and Nay Pyi Taw (Yesin) observed new rainfall recorded data associated with Low Pressure Area that formed over South Bay at March as shown in Table 2.
(c) Out of 2 Low Pressure Area, one further intensified into a depression in June. Tropical Storm occurred at Arabian Sea, Bay of Bengal and South China Sea at the same time. Due to the relationship of those three areas intensify the strong monsoon and heavy rainfall occurred along the Coastal area.
(d) During October due to a Depression crossing over land, (6) inches to (15) inches rainfall observed over Sagaing, Mandalay, Magway Regions and Chin and Rakhine States as shown in Table (3).
(e) During December Very Severe Cyclonic Storm "THANE" occurred at the end of 2011. For 2011, it was the strongest tropical Cyclone in the Bay Storm and also latest Storm. Due to the crossed of India Coast, bad weather didn’t occur in Myanmar but heavy rainfall achieved in some Area of Myanmar. THANE is the fourth Storm naming by Myanmar. Moreover, it is only one naming Storm of the Bay of Bengal in 2011.
(f) Out of 4 depressions, one in October caused flash flood in Pokokku district of Central Myanmar Areas with a lot of damage. Very Severe Cyclone Storm "THANE" and other three depressions have crossed over India and Sri Lanka Coast.
(Table – 1) List of Storm over the Bay of Bengal during 1991 to 2010
1991 / * / * / * / 1 / 1 / * / 1 / 1 / * / 2 / 1 / * / 7
1992 / * / * / * / * / 1 / * / * / * / * / 2 / 3 / * / 6
1993 / * / * / * / * / * / 1 / * / * / 2 / * / * / 1 / 4
1994 / * / * / 1 / 1 / * / * / * / * / * / 2 / * / * / 4
1995 / * / * / * / * / 1 / * / * / * / 1 / * / 2 / * / 4
1996 / * / * / * / * / 2 / 1 / * / * / * / 2 / 3 / 1 / 9
1997 / * / * / * / * / 1 / * / * / 2 / 1 / 1 / 1 / * / 6
1998 / * / * / * / * / 1 / * / * / * / * / 2 / 1 / * / 4
1999 / * / * / * / * / * / 2 / * / 1 / * / 2 / * / * / 5
2000 / * / * / 1 / * / * / 1 / * / 1 / * / 1 / 1 / 1 / 6
2001 / * / * / * / * / * / * / * / * / 1 / 1 / 1 / * / 3
2002 / * / * / * / * / 1 / * / * / * / * / 1 / 2 / 1 / 5
2003 / * / * / * / * / 1 / 1 / * / * / * / 2 / 1 / 1 / 6
2004 / * / * / * / * / 1 / 2 / * / * / 1 / 2 / 1 / * / 7
2005 / 1 / * / * / * / * / 1 / 1 / * / 2 / 1 / 2 / 2 / 10
2006 / 1 / * / * / 1 / * / * / 1 / 4 / 3 / 1 / * / 1 / 12
2007 / * / * / * / * / 2 / 2 / 1 / * / 1 / 1 / 1 / * / 8
2008 / * / * / * / 1 / * / * / * / 1 / 1 / 1 / 2 / 1 / 7
2009 / * / * / * / 1 / 1 / * / 1 / * / 1 / * / * / 1 / 5
2010 / * / * / * / * / 1 / * / * / * / * / 3 / 1 / 1 / 6
2011 / * / 1 / * / * / * / 1 / * / * / 1 / 1 / * / 1 / 5
Total / 2 / 1 / 2 / 5 / 14 / 12 / 5 / 10 / 15 / 28 / 23 / 12 / 129
Avg / 0.10 / 0.05 / 0.10 / 0.25 / 0.70 / 0.60 / 0.25 / 0.50 / 0.75 / 1.40 / 1.15 / 0.60 / 6.45
(Table – 2) Rainfall recorded during in 2011
No. / Date / Station / New record RF / Years from opening date of Station / Old record RF
mm / inch / mm / inch
1 / 10.1.2011 / Kyaukphyu / 75 / 2.95 / 46 / 35 / 1.38
2 / 10.1.2011 / Aunglan / 20 / 0.79 / 26 / 6 / 0.24
3 / 11.1.2011 / Thandwe / 72 / 2.83 / 64 / 23 / 0.91
4 / 11.1.2011 / Pyi / 30 / 1.18 / 46 / 24 / 0.94
5 / 11.1.2011 / Kabaaye(YGN) / 31 / 1.22 / 43 / 18 / 0.71
6 / 11.1.2011 / Aunglan / 22 / 0.86 / 26 / 20 / 0.79
7 / 17.3.2011 / Hpaan / 68 / 2.68 / 44 / 46 / 1.81