加利福尼亚州及美国西南部：万圣节周末“菠萝快车”大气河来袭，周六晚至周日晨南加州降雨最强、局部山洪风险上升
一股被气象界称为“菠萝快车”的大气河将于万圣节周末影响美国西南部与南加州，带来两轮降雨：第一轮在 10 月 30 日星期五影响得克萨斯州西部、新墨西哥州与亚利桑那州部分地区；第二轮自 10 月 31 日星期六起在南加州增强、周日凌晨达到最强，西南部内陆的降雨与部分高山降雪将持续至 11 月 2 日星期一。本篇为预报类快讯，区别于本站 10 月 30 日已刊的圣迭戈县万圣节周末备灾提醒（仅针对该县周六晚至周日晨的风暴准备事项）。
据美国国家气象局，万圣节周末亚利桑那州、科罗拉多州、内华达州与犹他州上空的大气总水汽含量可达 10 月底平均值的 2 至 3 倍，接近同期纪录。就在一周多前，亚利桑那州、内华达州、新墨西哥州与犹他州部分地区刚遭破坏性洪水袭击，此轮降雨的山洪威胁因此更受关注：得克萨斯州西部拉伯克与米德兰一带周五即可能出现局部山洪，沙漠西南部则面临更严重的山洪风险。
预报提醒，万圣节周末出行者应留意当地气象局的山洪预警与道路封闭信息，降雨强度与落区仍可能随预报调整。
Pineapple Express Atmospheric River to Soak Southwest and Southern California Over Halloween Weekend; Heaviest SoCal Rain Late Saturday into Sunday Morning
An atmospheric river known as a "pineapple express" will affect the U.S. Southwest and Southern California over Halloween weekend in two rounds of rain: the first reaches western Texas, New Mexico and parts of Arizona on Friday, October 30; the second strengthens over Southern California starting Saturday, October 31, peaks early Sunday, and brings rain and some high-elevation snow to the interior Southwest through Monday, November 2.
According to the National Weather Service, total atmospheric moisture over Arizona, Colorado, Nevada and Utah this weekend could reach two to three times the late-October average, near record levels for the season. Just over a week ago, destructive flooding hit parts of Arizona, Nevada, New Mexico and Utah, heightening concern: localized flash flooding is possible in western Texas around Lubbock and Midland as early as Friday, and the Desert Southwest faces a more serious flash-flood risk.
Travelers over Halloween weekend should watch local National Weather Service flash-flood warnings and road closures, as rainfall intensity and placement may still shift with updated forecasts.
来源：GSM·美国（原文链接）
图片来源：图：大气河天气系统示意。GOES imagery: CSU/CIRA & NOAA 摄，Public domain，经 Wikimedia Commons。 / An atmospheric river weather system (illustrative). Photo by GOES imagery: CSU/CIRA & NOAA, Public domain, via Wikimedia Commons.
