Evolution and Effects of Typhoon Rumbia (2018) after Recurvature and their Links to Northeast China Cold Vortex Anomaly

Typhoon Rumbia (2018) made landfall in Shanghai, China, immediately weakened and turned northward. According to the evolution of the middle tropospheric atmospheric circulation, Rumbia interacted with a cold vortex anomaly (CVA) split out of the Northeast China Cold Vortex (NCCV) before embedding in NCCV. It was found that Rumbia showed two enhancements at 500 hPa after recurvature. The first enhancement was related to the establishment and strengthening of upper-level jet stream, while the second was linked to the cold advection enhancement during the embedding period. When Rumbia approached the NCCV, it transferred energy to the CVA, aiding its development. Meanwhile, CVA continuously delivered cold advection to Rumbia, promoting the extratropical transformation of Rumbia. Furthermore, Rumbia brought severe precipitation after extratropical transformation, including direct precipitation and remote precipitation. The results indicated that severe direct precipitation was associated with the upper-level divergence zone. In contrast, heavy remote precipitation was attributed to the enhanced upward movement in the middle troposphere caused by the embedding process. This process was primarily convective precipitation, although it occurred under insufficient water vapour conditions. [Traduit par la r & eacute;daction] Le typhon Rumbia (2018) a touch & eacute; terre & agrave; Shanghai, en Chine, puis s'est imm & eacute;diatement affaibli et a tourn & eacute; vers le nord. Selon l'& eacute;volution de la circulation atmosph & eacute;rique de la troposph & egrave;re moyenne, Rumbia a interagi avec une anomalie de vortex polaire (AVP) s & eacute;par & eacute;e du vortex polaire du nord-est de la Chine (VPNC) avant de s'int & eacute;grer dans le VPNC. On a constat & eacute; que Rumbia pr & eacute;sentait deux renforcements & agrave; 500 hPa apr & egrave;s le recourbement. Le premier renforcement & eacute;tait li & eacute; & agrave; l'& eacute;tablissement et au renforcement du courant-jet en altitude, tandis que le second d & eacute;coulait du renforcement de l'advection d'air froid pendant la p & eacute;riode d'encastrement. Lorsque Rumbia s'est approch & eacute; du VPNC, il a transf & eacute;r & eacute; de l'& eacute;nergie & agrave; l'AVF, favorisant son d & eacute;veloppement. Pendant ce temps, l'AVP a continuellement fourni de l'advection d'air froid & agrave; Rumbia, favorisant la transformation extratropicale de Rumbia. En outre, Rumbia a entra & icirc;n & eacute; de fortes pr & eacute;cipitations apr & egrave;s la transformation extratropicale, y compris des pr & eacute;cipitations directes et des pr & eacute;cipitations & agrave; distance. Les r & eacute;sultats ont montr & eacute; que les fortes pr & eacute;cipitations directes & eacute;taient associ & eacute;es & agrave; la zone de divergence en altitude. Cependant, les fortes pr & eacute;cipitations & agrave; distance ont & eacute;t & eacute; attribu & eacute;es au mouvement ascendant accru dans la troposph & egrave;re moyenne caus & eacute; par le processus d'encastrement. Ce processus & eacute;tait principalement constitu & eacute; de pr & eacute;cipitations convectives, bien qu'il se soit produit dans des conditions de vapeur d'eau insuffisante.