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Very Severe Cyclonic Storm Lehar (Hindustani: लहर meaning "wave") was a tropical cyclone that primarily affected the Andaman and Nicobar Islands and the Indian state of Andhra Pradesh. Lehar was the second most intense tropical cyclone of the 2013 season, surpassed by Cyclone Phailin, as well as one of the two relatively strong cyclones that affected Southern India in November 2013, the other being Cyclone Helen. The origins of Lehar can be tracked back to an area of low pressure that formed in the South China Sea on 18 November. The system slowly drifted westwards and entered the Bay of Bengal, where it quickly consolidated into a depression on November 23. It moved west-northwest into an improving environment for further development before the system was named ''Lehar'' on November 24, after it had developed into a cyclonic storm and passed over the Andaman and Nicobar Islands into the Bay of Bengal. Lehar gradually intensified further into a very severe cyclonic storm, equivalent to a category 1 hurricane on the Saffir-Simpson hurricane wind scale (SSHWS), reaching its peak on November 26, with 3-minute sustained wind speeds of and a minimum central pressure of . Moving along a generally west-northwestward path in the following days, the storm passed over an area having cooler waters and a moderate vertical wind shear. The storm's low-level circulation center (LLCC) started losing its structure, triggering a weakening trend. Lehar rapidly weakened to a Depression on November 28 and its fully exposed LLCC made its second landfall over the coast of Andhra Pradesh near Machilipatnam. The same day, it was last noted as a well marked low pressure area over Andhra Pradesh. Extensive preparation was done in the wake of the storm by the authorities of the coastal districts of Andhra Pradesh and Odisha, including the evacuation of 45,000 people in low-lying areas. The storm's rapid weakening before landfall led to no reported fatalities and minimal damage. ==Meteorological history== On November 19, 2013 the Japan Meteorological Agency reported that a tropical depression had developed, about to the west of Kuala Lumpur, Malaysia. Over the next few days the system moved towards the west-northwest and moved into an extremely favourable environment, for further development while located over the Malay Peninsula during November 21. The system was subsequently last noted by the JMA during the next day, as it crossed 100°E and moved into the Andaman Sea. There, it developed a well-defined low-level circulation center (LLCC). The Joint Typhoon Warning Center (JTWC) issued a Tropical cyclone formation alert (TCFA) on the system, assuming that it would intensify further as it moves into warmer sections of the Bay of Bengal.〔 Tracking westward at over , the system gradually intensified over the next 24 hours. Early on November 23, the JTWC classified the system as a Tropical Storm, designating it with ''05B''.〔(【引用サイトリンク】url=http://www.webcitation.org/6LGa4vl12 )〕 A couple of hours later, the India Meteorological Department (IMD) started tracking this system as a Depression. It was initially assigned the code ''BOB 07''.〔(【引用サイトリンク】url=http://www.webcitation.org/6LMhaIK68 )〕 Early the next day, the IMD reported that BOB 07 had reached deep depression status,〔(【引用サイトリンク】url=http://www.webcitation.org/6LMhZz611 )〕 and immediately afterwards, they upgraded BOB 07 into a cyclonic storm, naming it ''Lehar''.〔(【引用サイトリンク】url=http://www.webcitation.org/6LMhZen3l )〕 Being located in an area of moderate vertical wind shear of around , convection gradually consolidated around the LLCC, though being slightly displaced towards the northwest.〔(【引用サイトリンク】url=http://www.webcitation.org/6LMez4V35 )〕 Later that day, Lehar developed a weak microwave eye-like feature.〔(【引用サイトリンク】url=http://www.webcitation.org/6LOB6soLb )〕 Lehar made its first landfall south of Port Blair, Andaman and Nicobar, early on November 25. However, it maintained strength.〔(【引用サイトリンク】url=http://www.webcitation.org/6LOBK7OqQ )〕 The cyclone strengthened further and developed strong radial outflow, compensating the moderate vertical wind shear in the region. Following this development, the IMD upgraded Lehar to a Severe Cyclonic Storm. The JTWC also upgraded the system to a Category 1 Tropical Cyclone on the SSHS with winds of over .〔(【引用サイトリンク】url=http://www.webcitation.org/6LOBJoYGo )〕〔(【引用サイトリンク】url=http://www.webcitation.org/6LOB6NaL8 )〕 However, multispectral satellite imagery showed that a deep central dense overcast was obscuring the low level circulation. The JTWC had poor confidence in the storm's position and couldn't exactly locate its center.〔(【引用サイトリンク】url=http://www.webcitation.org/6LPW23Avk )〕 Lehar continued to track in a westerly direction just along the periphery of a subtropical ridge.〔(【引用サイトリンク】url=http://www.webcitation.org/6LPWEW70G )〕 Early on November 26, the IMD upgraded Lehar to a Very Severe Cyclonic storm. Meanwhile, they have warned the coastal districts of Andhra Pradesh and Odisha of heavy rainfall and strong winds.〔(【引用サイトリンク】url=http://www.webcitation.org/6LPWa6lp3 )〕 Under the steering influence of the subtropical ridge, Lehar continued to track in a west-northwesterly direction. The storm maintained a peak 1-minute average sustained windspeed of .〔(【引用サイトリンク】url=http://www.webcitation.org/6LRBytvtm )〕 On passing over cooler waters and experiencing moderate easterly vertical wind shear, the storm started losing intensity.〔(【引用サイトリンク】url=http://www.webcitation.org/6LRByfJB8 )〕 Though deep convection persisted along its well-define center, microwave imagery depicted drier air, restricting moist inflow along the southwestern periphery of the system.〔(【引用サイトリンク】url=http://www.webcitation.org/6LRByQISo )〕 On November 27, the convection around the storm's center started losing its structural organization. A scatterometer pass indicated the elongation of the LLCC with weakening wind field.〔(【引用サイトリンク】url=http://www.webcitation.org/6LRWpqgvG )〕 Thereafter, Leher rapidly weakened into a Depression and made landfall south of Machilipatnam, Andhra Pradesh on November 28. Increased frictional forces led to the degeneration of the storm into a well-marked low pressure area, while it moved inland. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cyclone Lehar」の詳細全文を読む スポンサード リンク
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