Country Report of Bangladesh
Review of 2011 Cyclone Season (Agenda item 3)
Cyclone ‘Thane’ during 26-30 December 2011
A low pressure area formed over south Bay of Bengal on 25 December 2011. It intensified into a Well Marked Low and then to a Deep Depression at 0300UTC on 26 December over Southeast Bay and adjoining area (Lat. 09.5°N, Lon. 87.5°E). The system moved northwards over the same area and intensified into a Cyclonic Storm ‘Thane” (ECP: 994 hPa) at 0000UTC of 27 December and its central location was at Lat. 11.0°N, Lon. 87.5°E. The system then changed its direction of movement, moved west-northwestwards first and then northwestward and westward till 0000UTC of 29 December. At 0000UTC of 29 December the system intensified further into a Severe Cyclonic Storm ‘Thane” (ECP: 984 hPa) over Southwest Bay and adjoining West Central Bay (Lat. 12.5°N, Lon. 84.5°E). After that it moved west-southwestwards and intensified further into a Severe Cyclonic Storm with a Core of Hurricane Winds ‘Thane” (ECP: 980 hPa) over the same area (Lat. 12.0°N, Lon. 83.0°E) at 0600UTC of 29 December. Then the system moved west/west-southwestwards and finally crossed the coast of Tamilnadu (between Nagapatnam and Chennai) of India in the early morning of 30 December and positioned over Punducherry and weakend afterwards by giving precipitation and became unimportant. The track associated with the Severe Cyclonic Storm with a Core of Hurricane Winds ‘Thane’ is illustrated in Figure below.
Figure: Track associated with the Severe Cyclonic Storm with a Core of Hurricane Winds Thane’ during 26-30 December 2011
Report On The Impact Of Tropical Cyclones (Agenda item 3.2)
There was no tropical cyclone directly affecting Bangladesh in 2011.
Weather Condition of Bangladesh during January to June 2011
Rainfall condition during winter season (January-February) in Bangladesh
Temporal variation of country averaged rainfall during January and February is shown in Fig. 1. It is found that there were insignificant amounts of rainfall recorded in Bangladesh during these months. Only one rain spell observed during 15-17 January 2011 under the influence of westerly trough associated with the extension of seasonal low located over south Bay of Bengal covering southeastern, central and north eastern parts of Bangladesh. During this period the maximum amount of 09 mm rainfall recorded at Teknaf (17 January). As a result the country averaged rainfall of January was below than normal by 84.1%. Under the same synoptic situation an active rain spell also observed during 16-17 February 2011 and light to moderate rainfall recorded over northwestern part of Bangladesh with the maximum amount of 26 mm rainfall recorded at Dinajpur on 16 February. During 19-21 February 2011 another weak rain spell observed which influenced most part of the country but the rainfall amounts were insignificant. Hence the country averaged rainfall of February was 87.0% below than normal.
Fig. 1: Recorded daily country average rainfall of Bangladesh during January and February in 2011
Weather condition during Pre-monsoon season in Bangladesh
In March isolated rainfall recorded in Bangladesh on 09, 11, 13-19, 21 and 23-24 March due to the presence of weak westerly trough in association with the local convection and incurring moisture from the Bay of Bengal. During this period thunderstorms with wide spread rainfall with isolated heavy falls were recorded in the southeastern parts. For the period of 26-31 March under the same synoptic situation with more extension of westerly trough towards south, light to moderate rainfall with isolated heavy falls in association with thunderstorm were observed. During this spell the maximum 80 mm of rainfall (31 March) were recorded at Chittagong, followed by 68 mm at Sandwip (30 March) and 55 mm at Hatiya (30 March). But the country averaged rainfall of March was 17.0% below than normal.
In May the influence of Western Disturbance was continuously strong over West Bengal of India and Bangladesh and hence widespread moderate to moderately heavy rainfall with heavy to very heavy falls were recorded over the country. The significant amounts of rainfall of 136 mm recorded at Hatiya (22 May), 114 mm at Chandpur (27 May), 104 mm at Hatiya (29 May) and 101 mm at Srimongal (02 May). Spatial analysis reveals that the accumulated monthly rainfall was above than normal by 22.5% in Rangpur and 21.3% in Chittagong divisions but it was below than normal by 22.4% in Dhaka division and normal in all other divisions. As a result the country average rainfall was above than normal by 5.9%. Recorded daily country average rainfall of pre-monsoon season of Bangladesh is illustrated in Fig. 2.
Fig. 2: Recorded daily country average rainfall of pre-monsoon season of Bangladesh
Rainfall situation during June 2011 in Bangladesh
Southwest monsoon approached upto Yangoon coast on 31st May 2011. It advanced to Teknaf coast of Bangladesh on 07 June and extended to Chittagong division of Bangladesh on 08 June 2011 and finally covered whole Bangladesh on 12 June 2011. Under the influence of strong western disturbance and moisture incursion in support of the approaching monsoon towards Bangladesh an active rain spell observed during 7-11 June over Dhaka, Chitttagong and Sylhet divisions. In this period widespread moderate to moderately heavy rainfall with heavy to very heavy falls were recorded over the country. The maximum amounts of rainfall of 131 mm, 105 mm and 98 mm were recorded at Sylhet (10 June), Mongla (11 June) and Mongla (09 June) and the maximum country average rainfall of 14.2 mm was observed on 08 June during this spell. Southwest monsoon set over Bangladesh with active influence. Hence another active rain spell experienced over the country with wide spread heavy to very heavy rainfall during 14-19 June with the presence of a monsoon depression formed over Northwest Bay and crossed Bangladesh-West Bengal coast near Raimongal River.
During this period the maximum amounts of 145 mm rainfall recorded at Cox’s Bazar (18 June) and Maijdi Court (17 June) and the maximum country average rainfall was 40.9 mm on 18 June. A longer duration of rain spell also experienced during 23-30 June under the influence of active monsoon phase and positioning of monsoon trough over central part of Bangladesh and another monsoon trough to North Bay. Heavy to very heavy falls were recorded over most parts of the country. During this period the maximum amounts of 178 mm rainfall recorded at Teknaf (27 June) followed by 146 mm at Rangamati (25 June) and the maximum country average rainfall was 44.0 mm on 30 June. The monthly accumulated rainfall of June was below than normal in Rangpur division; normal in Barisal, Rajshahi and Sylhet divisions and above than normal in Dhaka, Chittagong and Khulna divisions. As a result the country averaged rainfall was above than normal by 9.8%. The recorded daily country average rainfall of June is illustrated in Fig. 3.
Fig. 3: Country average daily rainfall of Bangladesh during June 2011
Meteorological component (Agenda item 5.1)
a. Surface Observation
There are 35 surface observatories in Bangladesh Meteorological Department.
b. Upper Air Observation
(i) There are 3(Three) Rawinsonde observatories in Bangladesh Meteorological Department.
(ii) There are 10(Ten) Pilot Balloon observatories in Bangladesh Meteorological Department.
c. Brief description of ground equipment
(i) Cyclone Detection Radars:
• In 2007, two S-band Doppler radar systems were established and operational by replacing the conventional radar at Cox’s Bazar and Khepupara.
• These two S-band Doppler Radars are utilized to monitor tropical cyclones and quantitative rainfall forecasting in the coastal belt.
(ii) Radar for Flash Flood Warning
• In 2009, another Hydrological cum Meteorological S-band Doppler Radar System was set up at Moulvibazar (northeastern side of Bangladesh) with the grant aid of Japan.
• The flash floods due to heavy rainfall from severe convection over the steep hilly region of India in the north eastern part of Bangladesh causes enormous loss to crops and infrastructure within a short span of time. To monitor this and its associated rainfall this Radar System is being used.
(iii) Storm Detection Radars
There is One (1) Radar at Rangpur, North-western part of Bangladesh to monitor local severe storms (Locally known as Kalboishakhi) in the north-western part and central part of Bangladesh.
(iv) Automatic Weather Station
6(Six) AWS stations have been installed at six different observatory in BMD under JICA project on “Development of Human Capacity on Operation of Weather Analysis and Forecasting.”
d. Meteorological Satellite Reception and data processing System
· Under the programme of Japan International Cooperation Agency, BMD is receiving MTSAT satellite image at 30 minutes interval.
· Recently BMD is using MICAPS 3.1 to receive satellite imagery from FY2D through Cma Cast system.
Numerical Weather Prediction in BMD
WRF Model:
Current Status:
§ WRF model is running in BMD since July 2010.
§ Using GFS data from NCEP.
§ Time : 72 hours, at 00 UTC
§ Resolution : 27 Kms
§ Start at : 10:00 AM
§ Time required: About 1 hour 20 min.
§ Products Generating: Rainfall forecast for 24, 48 & 72 hours and same with district boundary.
§ Initially model ran manually but recently model running automatically.
Requirement:
§ Technical support and Training for different levels including Advance WRF.
§ Model run using ECMWF data and GSM data of JMA.
§ Data assimilation
§ Large computing power to increase resolution and decrease run time.
§ Validation using different statistical technique.
IIT-D Storm Surge Model:
Current Status:
ü Operationally using in BMD
ü Well tested and simulated for different cyclones with different parameter
ü Both LINUX and Windows version are installed in BMD.
ü People of BMD are capable to run the model
ü BMD people received several training on this model
Requirement:
§ High resolution output
§ Input data from other models
MRI Storm Surge Model
Current Status:
ü BMD arrange a 5-day long training workshop in December 2010, facilitating by RIMES Bangkok
ü Other model products (surface wind, pressure) can be used as input of the model.
ü GSM data of JMA using to run the model along with conventional parameters.
ü BMD people are capable to handle the model.
ü Not yet tested well
Requirement:
§ Further training at different levels including advance level are needed.
§ More tuning needed for BoB Basin
§ Coupling with WRF or other model
§ Use ECMWF data or other model data as input.
Bangladesh Meteorological Department has been using JMA Global Spectral Model (GSM) for Numerical Weather Prediction since October 2010. The resolution for the surface is 0.25°x0.25° and for upper air is 0.5°x0.5°. The model out are updated everyday accordingly at BMD’s website www.bmd.gov.bd
Telecommunication Network in BMD
Meteorological Data from RTH New Delhi and 10 synoptic observatories of BMD are exchanged on routine basis through WMO’s GTS. All the 35 observatories of BMD have been connected with NMCC Dhaka either by TP or Telephone and single sideband (SSB) etc. or by all the three systems. Some of the observatories are connected through internet with NMCC and data are collected on real time basis by using Meteorological Data Acquisition software. The communications between Storm Warning Centre (SWC) and Radar Station at Cox’s Bazar and Khepupara have been upgraded to VSAT link. NMCC uses MSS software obtained from WMO/UNDP Regional Computer Network programme for reception and transmission of all meteorological data.
* All the observatories and operational offices of BMD are functional round the clock under the direct administrative and technical control of the two Regional Meteorological Centers.
* Staff are available to run BMD activities in 24x7 mode
COASTAL INUNDATION FORECASTING DEMONSTRATION PROJECT (CIFDP)
Bangladesh Sub-Project – CIFDP-B
The Bangladesh CIFDP sub-project, denoted CIFDP-B, formally started after achieving the Initial National Agreement in October, 2011. Immediately thereafter, a Stakeholders Workshop, encompassing both a user requirements component and a technical component, was organized and held 28 November - 1 December 2011, hosted at the Bangladesh Meteorological Department in Dhaka.
The Stakeholders Workshop involved more than 50 participants including members of the Project Steering Group and other international experts as well as a large number of stakeholder agencies in Bangladesh, including the Bangladesh Meteorological Department (BMD), Bangladesh Water Development Board (BWDB), Cyclone Preparedness Programme (CPP), Disaster Management Bureau (DMB), and Bangladesh Coast Guard (BCG), Regional Integrated Multi-Hazard Early Warning System For Africa and Asia (RIMES), and many others.
The outcomes of the Workshop included a Definitive National Agreement and Terms of Reference for the CIFDP-B National Coordination Team (NCT), as well as a proposed work plan for the first year of the project. The DNA and ToR has been submitted for senior management approval of the signatory agencies.
Information of Bangladesh Meteorological Department’s Sixth Five Year Plan
(2011-2015)
Sl.No / Project Name &
Implementation
period / Goals / Targets / Activities
(program/project)
1. / Development of
Human Capacity on
Operation of Weather
Analysis and
Forecasting. July
2010- Dec 2012 / The overall goal of the Project is to improve the capacity of Meteorological Service through improving the weather analysis and forecasting by Numerical Weather Prediction technique. It will also improve the capacity of BMD in climate data
management and its application in climate change impact assessment and scenario development,
management of climate data and running of
climate model Through calibration of all the radar, the issuance of the quantitative rainfall forecast BMD will be improved. / This Project is targeted on the development of human capacity of BMD on weather analysis and forecasting, introduction of basic knowledge and methods of the aforesaid modern weather analysis technologies as well as utilizing the equipment which are and to be established under the grant aid assistances of the Government of Japan including the other systems utilized for the weather forecasting and analysis. / To conduct the training on Meteorological Observation, basic NWP system, data acquisition and quality control and maintenance of the instruments.
To revise the existing guideline on Meteorological Observation in accordance with latest WMO edition.
To establish the correlation between actual rainfall and estimated rainfall for quantitative rainfall forecasting.