台灣地區暖季弓形回波並非常見之天氣現象，1991～2009 年僅有三個弓形回波個案造成桃園機場
產生＞16 ms-1之強陣風，而南台灣則僅有一個個案診斷分析研究發表於期刊文獻上。本文即針對台灣地區產生地面破壞性強風之弓形回波，進行綜觀環境、都卜勒雷達回波及徑向風場分析，以了解其形成與
發展之環境條件以及雷達回波型態與風場結構之中尺度特徵，並比較其與中緯度和熱帶地區者之異同。分析結果顯示，台灣地區弓形回波生命史約2.5～7 小時，具有兩種不同發展型態，一為獨立型，係由一獨立線狀回波或颮線於鋒前形成，長度較大最長可達200公里；另一為線尾型，係在鋒面上之颮線線尾形成，長度較小僅約100公里。弓形回波初生期主軸均呈東北－西南走向，回波中段凸出前緣造成之地面西至西北強風，大致為反應中層後方內流噴流之結果。在弓形回波成熟期，北台灣個案於系統南（北）側1～3 公里高度，分別出現中尺度反旋式（氣旋式）渦旋，但南台灣個案僅在弓形回波北端中低層存在一個氣旋式渦旋。環境條件分析顯示，弓形回波因在鋒面前暖區（獨立型）或鋒面上（線尾型）形成與發展，故其環境條件大致反映其與鋒面相對位置之關係。獨立型具有較大CAPE（1200～3047m2s-2）與較小低層垂直風切（6~12 ms-1），線尾型具有較小CAPE（749 m2s-2）與較大低層垂直風切（17.5
ms-1）。
台灣地區弓形回波之雷達回波結構類似發生於中緯度地區者，包括線狀回波中段向前凸出、凸出前緣具有強烈回波梯度、具有一支或兩支後方內流噴流造成系統後方拖曳區之弱回波凹洞、以及一對書夾式渦旋偶等。相異處包括後方內流噴流強度明顯低於美國地區之典型個案，其造成地面破壞性強風之強度與危害區域未達美國地區derecho 標準，近地層亦無中尺度渦旋且無伴隨龍捲風，劇烈程度與出現在熱帶地區者較為相似。

Bow echo in not a common phenomenon in the warm season over Taiwan area .Over northern Taiwan, there were only three events which produced strong gale winds > 16 ms-1 at Taoyuan International Airport, whereas over southern Taiwan there was only one event being reported in the open literature. The main purpose of this paper in to study the mesoscale characteristics of radar reflectivity and wind field associated with bow echo as well as the environmental conditions for the development of bow echo which produced strong gale winds. Also, the differences and similarities of bow echoes over Taiwan and other areas will be investigated. Results show that bow echoes occurred over Taiwan had a life time of 2.5~7 hours with two different types of development. The isolated type developed from an isolated line echo or a squall line which occurred in the warm sector ahead of front. The length scale was relatively larger with a maximum of 200 km. The line-tail type developed from the tail end of a squall line which formed along a front. The length scale was relatively small only about 100 km. At the formation stage, the axis of bow echo oriented in a NE-SW direction. The central part of the bow echo is signified the leading edge of the system with strong surface gust
winds reflecting the strength of rear inflow jet at mid-level. At the mature stage, a mesoscale cyclonic–anticyclonic vortex couplet was observed at 1~3 km level for the bow echo over northern Taiwan, whereas that occurred over southern Taiwan only cyclonic vortex over northern part of the bow echo was observed. Environmental conditions for different types of bow echoes reflected the relative position with respect to front. The isolated type developed in the warm sector ahead of front had conditions with relatively large CAPE (1200~3047 m2s-2) and small low-level vertical wind shear (6~12 ms-1). The line-tail type, on the other hand, developed along the front had condition with small CAPE (749 m2s-2) and large low level vertical shear (17.5 ms-1).
There are some similarities of the bow echoes occurred over Taiwan and the other areas. These include the center of the bow forming a speared, a strong low-level reflectivity gradient along the leading edge of the
bow, and one or two branches of rear inflow jets forming rear inflow notches of weak echo along the trailing edge of the bow, as well as the look-end vortices. There are some differences as well. The rear inflow jet was weaker for the Taiwan cases as compared to those occurred over the United States area. The strength of surface gust wind associated with the Taiwan case was also weaker and never reached derecho strength as observed over the United States. The tornado and mesoscale vortices at the surface level were never observed for the Taiwan case. The strength of the bow echo over Taiwan was similar to those occurred in the tropical area.