Cyclone Yaas, May 2021 cancelled. Air transport is also currently suspended. The army remains on high alert for immediate deployment. Second Advisory Water supply from the 111-year-old iconic Tallah tank (largest overhead The deep depression over East-central intensified into a water tank in the world) that has withstood earthquakes and storms to Cyclonic Storm on May 24 and further intensified into a Severe Cyclonic Storm provide potable water to Municipal Corporation will be suspended as Yaas rapidly over the past 36 hours. According to the IMD Bulletin on May 25 a part of the civic strategy due to the storm. The Cellular Operators’ at 1215 IST, the phenomenon is very likely to move north-westwards, Association of (COAI) along with infrastructure providers (IPs) and strengthening further into a Very Severe Cyclonic Storm (118-166 kmph) in internet service providers (ISPs), have geared up to ensure that the adverse the next 12 hours. It is expected to reach near north and impact of Yaas remains minimal by implementing measures such as coasts very close to Chandbali- by the early morning of May 26. intra-circle roaming, additional Cell on Wheels (CoW) to ensure connectivity. The forecasted landfall of VSCS Yaas is on Odisha-West Bengal coasts between The Energy Department in Odisha has mobilized workforces that would also Paradip and Sagar Island close to the north of Dhamra and south of be increased if necessary to be engaged in the restoration of services at the around noon on May 26, 2021. earliest in the event of a disruption and have approved special labour rates for the post-cyclone restoration work be undertaken by Discoms and OPTCL. Highest danger warnings have been issued for Dhamra and Paradip ports, with expected wind speeds 150-160 kmph gusting 180 kmph over In the coastal and adjoining interior districts of North Odisha and West , , and Balasore causing rough seas. Bengal, total destruction of thatched houses, extensive damage to kutcha houses, and some damage to pucca houses can be expected. Disruption of In the wake of the cyclone, preparedness measures are in full swing in Odisha electricity supply in some areas due to the uprooting of power and and West Bengal. Over 6,900 centres accommodating 7.5 people have communication poles, disruption of power lines, etc., is expected. Farmers been arranged to be used as cyclone shelters. Over 81,661 people living in anticipate widespread damage to standing crops, plantations, horticulture ‘vulnerable areas’ have already been evacuated by district administrations crops such as coconuts, mangoes, papayas, bananas, guavas, pineapples and and Marine Police Force in Odisha. The evacuation process is being expedited others. and the ADGP (Law & Order) has briefed media persons that they shall be completing the evacuation drive by the evening of May 25. The government has mobilized diesel generator sets, water tankers and essential food and non-food items for providing relief to the affected and People living in low-lying and vulnerable areas have started moving to the displaced population. As many as 27,000 electric poles, 2600 km conductors, multi-purpose cyclone shelter at and East Midnapore, and 45 NDRF 1125 transformers, and 160 generators besides 500 vehicles are kept ready teams have been deployed across West Bengal. Railway services have been for restoration work during the post-cyclone period. Amid the ongoing temporarily suspended in Odisha and West Bengal – over 90 trains have been

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coronavirus crisis, 308 CHCs and 635 other health infrastructures are kept State 25th May 26th May 27th May ready with 215 additional generators and adequate medicines. places in Howrah, heavy rainfall at isolated places Purulia, west Hooghly, Kolkata & over Purulia, Nadia, Bardhaman, Due to the full moon, it is expected that there will be high tides affecting parts north 24 Parganas Murshidabad, east Bhirbhum, of East Midnapore and in South 24-Parganas. Maximum inundation extent up districts; Light to Bardhaman, Howrah, Malda, to 7 km is expected in coastal areas of Bhadrak, where the nearest habitation moderate rainfall at Hooghly, Kolkata, north 24 Darjeeling, is in Mohanpur. most places Parganas, Haldia, Darjeeling, Kalimpong, Kalimpong Districts Jalpaiguri

Light to moderate Table 1: Forecasted impact1 on the States in the next 48 hours - Rainfall rainfall at most places with heavy State 25th May 26th May 27th May to very heavy rainfall and Andhra Light to moderate at extremely heavy Pradesh many places; heavy falls at isolated (North falls at isolated places places Coastal) Light to moderate Extremely heavy at many places; rainfall in Extremely heavy falls at isolated Light to moderate heavy to very Heavy to very heavy rainfall and Jagatsinghpur, places in Jagatsinghpur, rainfall at most places heavy rainfall at extremely heavy falls at isolated Kendrapara, Kendrapara, , Bhadrak, with heavy rainfall at isolated places; places Bhadrak, Balasore Balasore, Mayurbhanj, Heavy rainfall at isolated places extremely heavy districts; Heavy , Dhenkanal, isolated places in Odisha over southeast rainfall over Ganjam, Keonjhargarh; Heavy to very north interior Jharkhand Dhenkanal, heavy rains at a few places; Odisha Keonjhargarh heavy raifall at isolated places Light to moderate at Light to moderate at many districts; Light to in , Khurda, Angul, Assam & many places; heavy to places; heavy to very heavy moderate at many Deogarh, Sundergarh; Meghalaya very heavy rainfall at rainfall at isolated places places; isolated places Heavy to very heavy Extremely heavy rainfall at Heavy rain at rainfall over isolated places over Medinipur; isolated places in West Bengal Medinipur, South 24 heavy to very heavy rainfall at , west Parganas; Heavy isolated places over Jhargram, Medinipur, rainfall at isolated Bankura, ; Bankura,

1 Spatial rainfall distribution: Isolated: <25%, A few: 26-50%, Many: 51-75%, Most: 76-100%; Rainfall amount (mm): Heavy rain: 64.5 – 115.5, Very heavy rain: 115.6 – 204.4, Extremely heavy rain: 204.5 or more

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Table 2: Forecasted impact on the States in the next 48 hours – Wind State 25th May 26th May 27th May Squally wind (40-50 State 25th May 26th May 27th May kmph gusting 60 Andhra Squally winds (50-60 kmph gusting Squally wind (55-65 kmph) near the coast; Pradesh to 70 kmph) Srikakulam, kmph gusting 75 Jharkhand gale winds (90-120 (north Vijayanagaram & kmph) near the coast kmph gusting to 130 coastal) Vishakhapatnam districts kmph) over southeast Jharkhand Gale winds (65-75 Gale winds (155-165 kmph gusting Squally wind kmph gusting to 85 to 185 kmph) Jagatsinghpur, (50-65 kmph) over northwest Kendrapara, Bhadrak, Balasore; kmph Bay of Bengal and 120-130 kmph gusting to 145 kmph gusting to 70 The Bay of Bengal accounts for only 5% of tropical globally, but along & off north over Mayurbhanj; 80-90 kmph kmph) over tropical cyclones on the eastern coast of India results in 80% of tropical Odisha including gusting to 100 kmph would prevail Kendrapara cyclone-induced fatalities worldwide due to the shallow continental shelf that Jagatsinghpur, over Puri, Cuttack, Khurda, Jajpur , Bhadrak, amplifies storm surges and a very dense population2. In India, tropical and Nayagarh districts; 60-80 Balasore, Odisha Kendrapara, Puri, cyclones usually occur in April-May (pre-monsoon season) and October- Bhadrak, Balasore kmph gusting to 90 kmph along and Keonjharga off Ganjam and remaining interior rh, November (post-monsoon). In 2020, there were two pre-monsoon cyclones – Squally wind (40-50 districts of north Odisha; 60-80 Mayurbhan Amphan (Super Cyclonic Storm) impacting the eastern coast of India and kmph gusting 60 kmph gusting to 90 kmph over j, Deogarh, Nisarga (Severe Cyclonic Storm) impacting the western coast. kmph) would prevail Ganjam, Dhenkanal & Keonjhar Sundergarh over Ganjam, Khurda, districts; 50-60 kmph gusting to 70 Districts Cuttack, Jajpur & kmph over Angul, Deogarh & ANALYSIS Mayurbhanj Districts Sundergarh RMSI has analysed potential flood and wind impact due to Cyclone Yaas (based on the IMD bulletin on May 25, 2021 at 1215 hours IST). The following Gale winds (65-75 Squally winds (60-80 kmph gusting Squally wind kmph gusting to 85 to 90 kmph) Bankura, Purulia, (50-65 maps depict the potential flood and wind affected areas. kmph) over coastal Howrah, Hooghly, Nadia & kmph The following districts may be affected by floods in the next 24-48 hours: WB including East Burdhaman districts; 50-60 kmph gusting to 70 Medinipur, Eouth 24 gusting to 70 kmph Birbhum & kmph) over  West Bengal: Murshidabad, Nadia, North 24 Parganas, South 24 Parganas, Kolkata Murshidabad districts West Parganas, Haora West Bengal districts Medinipur,  Odisha: Bhadrak, Kendrapara, Baleshwar, Puri, Jagatsinghpur, Jajapur. Jhargram, Squally wind (40-50 Bankura, kmph gusting 60 Purulia kmph) would prevail Districts over Howrah, Hooghly, North 24 2 Neetu, S., et al. "Premonsoon/postmonsoon Bay of Bengal tropical cyclones intensity: Role of air‐ Parganas Districts sea coupling and large‐scale background state." Geophysical Research Letters 46.4 (2019): 2149-2157.

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Most damaging winds of 117 kmph and higher will be experienced in Odisha. Mostly in West Bengal, the winds speeds will be less than 88 kmph, except for a few places. Wind hazard may impact the following district on May 25 and 26 mainly –  Odisha: Baleshwar, Bhadrak, Kendrapara, Mayurbhanj, Jajapur, , Jagatsinghpur, Dhenkanal  West Bengal: West Medinipur, East Medinipur, (some part of) South 24 Parganas, Bankura, Purulia.

Figure 2: Potential impact due to flood and surge in Odisha - Cyclone Yaas

Figure 1: Potential impact due to wind - Cyclone Yaas

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DISCLAIMER: This report contains information generated through the analyses, and model predictions based on data provided by IMD and compiled using proprietary computer risk assessment technology of RMSI Pvt. Ltd. The technology and data used in providing this information is based on the scientific data, mathematical and empirical models, and encoded experience of scientists and specialists (including without limitation, earthquake engineers, wind engineers, structural engineers, geologists, seismologists, meteorologists, and geotechnical specialists). As with any model of physical systems, particularly those with low frequencies of occurrence and potentially high severity outcomes, the actual losses from catastrophic events may differ from the results of simulation analyses. RMSI specifically disclaims any and all responsibilities, obligations and liability with respect to any decisions or advice made or given as a result of the information or your use thereof. RMSI specifically disclaims any and all responsibilities, obligations and liability including all warranties, whether expressed or implied, with respect to the report, including but not limited to, warranties of non-infringement, merchantability and fitness for a particular purpose. In no event shall RMSI (Or its subsidiary, or other affiliated companies) be liable for direct, indirect, special, incidental or consequential damages with respect to any decisions or advice made or given as a result of the contents of this information or your use thereof. The material contained in this report is the copyright of RMSI and may be used only for informational purposes only. RMSI makes no representations or warranties with respect to this information. For using any information from this report, you agree to the terms and provisions as outlined in this disclaimer. If you do not agree to them, please do not use this report.

Figure 3: Potential impact due to flood and surge in West Bengal - Cyclone Yaas

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