热带风暴雷切尔逼近美墨边境：南加州罕见发布热带风暴观察，西南各州防洪水
大西洋飓风伊萨亚斯的残余刚给美国东南部带来洪灾，热带风暴雷切尔（Rachel）又逼近美墨边境。美国国家飓风中心预报，雷切尔预计周六晚在下加利福尼亚半岛北部登陆，给加州、亚利桑那和内华达带来洪水般的暴雨，南加州包括圣迭戈在内已罕见地发布热带风暴观察预警。
对南加州而言，热带风暴观察极为少见。NHC提醒，即使风暴本体远在数百英里外，其激起的涌浪仍让海里游泳变得危险，雷切尔的涌浪将持续影响南加州南向海滩至整个周末。
内陆地区的主要威胁是暴雨与洪水。风暴登陆后带来的大雨将横扫美国西南部，亚利桑那和内华达部分地区也可能出现洪水。美墨边境墨西哥一侧，下加州北部同样面临破坏性阵风与强降雨。
值得一提的是，本周末美国西南部面临双重威胁：南方更强的四级飓风西蒙预计周日登陆墨西哥太平洋岸后，其内陆雨带将北上穿过纳亚里特、进入锡那罗亚，带来持续到周一的强降雨。美墨两国气象部门均呼吁，风暴潮预警即意味着必须立即行动。（消息来源：美国国家飓风中心、路透社、彭博）
Tropical Storm Rachel Approaches US-Mexico Border: Rare Tropical Storm Watches for Southern California, Flood Threat Across the Southwest
As the remnants of Atlantic Hurricane Isaias deliver flooding rains to the U.S. Southeast, Tropical Storm Rachel is bearing down on the U.S.-Mexico border. The U.S. National Hurricane Center forecasts Rachel to strike near northern Baja California late Saturday, bringing flooding rains across the U.S. Southwest — including parts of California, Arizona and Nevada — with rare tropical storm watches issued across Southern California, including for San Diego.
Tropical storm watches are an exceptionally rare event for Southern California. The NHC cautioned that swimming is dangerous in surf generated by a tropical system even when the storm itself is hundreds of miles away; Rachel's swell will continue affecting south-facing beaches in Southern California through the weekend.
The main inland threat is heavy rain and flooding. The storm's downpours are expected to sweep across the U.S. Southwest after landfall, with flood risks in parts of Arizona and Nevada as well. Northern Baja California faces damaging wind gusts and heavy rain on the Mexican side of the border.
The weekend brings a double threat to the region: to the south, major Category 4 Hurricane Simon is expected to make landfall on Mexico's Pacific coast on Sunday, with its inland rain track carrying heavy precipitation northward through Nayarit and into Sinaloa through Sunday and Monday. Authorities on both sides of the border urge residents to follow local emergency management guidance — and treat any storm surge warning as a directive requiring immediate action. (Sources: U.S. National Hurricane Center, Reuters, Bloomberg)
图片来源：图：墨西哥太平洋沿岸外海的热带气旋卫星云图（资料图）。NOAA官方影像，公有领域，来源：Wikimedia Commons
