风暴预测中心：选举日密西西比河谷有强雷暴边缘风险，约2,059万人处于风险区
美国国家气象局（NWS）风暴预测中心（SPC）11月3日下午发布的当日强对流天气展望显示，选举日当天，美国中部从下密西西比河谷、田纳西河谷到中密西西比河谷一带处于强雷暴「边缘风险」（Marginal Risk）之下；风险区面积约 26.8 万平方英里、覆盖人口约 2,059 万，包括 Memphis、Nashville、St. Louis、Shreveport、Des Moines 与 Little Rock 等城市。
风暴预测中心表示，11月3日下午至夜间，从 Sabine 河谷与下密西西比河谷向北至中密西西比河谷的雷暴，可能带来局地强阵风，并可能出现一到两个短暂龙卷风；风险区内龙卷风概率为 2%、破坏性阵风概率为 5%。该展望有效期至11月4日 12:00 UTC（中部时间凌晨 6 时）。
据该中心当天下午的更新，路易斯安那州西北部上空已观测到若干超级单体风暴结构与弓形回波段，最强风暴预计傍晚向东扩散至阿肯色、路易斯安那与密西西比三州交界地带，夜间威胁可能持续至田纳西州西部与肯塔基州西部。
当天是美国 2026 年中期选举投票日。据《今日美国》汇总的国家气象局预报，北加州选举日有降雨，旧金山湾区办公室预报 North Bay 降雨量可达 0.10 至 0.50 英寸、傍晚可能有雷暴；佛罗里达州东南部则仍面临持续大雨威胁；美国西部其余大部分地区选举日以晴到多云为主。
（来源：美国国家气象局风暴预测中心）
Storm Prediction Center: Marginal Severe Storm Risk Over the Mississippi Valley on Election Day, About 20.6 Million People in the Risk Area
The National Weather Service (NWS) Storm Prediction Center (SPC) said in its Day 1 convective outlook issued on the afternoon of Nov. 3 that parts of the central United States, from the Lower Mississippi Valley and the Tennessee Valley into the Mid-Mississippi Valley, are under a marginal risk of severe thunderstorms on Election Day. The risk area covers about 268,216 square miles and a population of roughly 20.59 million, including Memphis, Nashville, St. Louis, Shreveport, Des Moines and Little Rock.
Thunderstorms from the Sabine Valley and the Lower Mississippi Valley northward into the Mid-Mississippi Valley could produce isolated severe wind gusts and perhaps a brief tornado or two on the afternoon and night of Nov. 3, the center said, putting the tornado probability at 2 percent and the damaging-wind probability at 5 percent within the risk area. The outlook runs through 12:00 UTC on Nov. 4 (6 a.m. Central).
In its afternoon update, the center said several supercell structures and bowing segments had been observed across northwest Louisiana, with the strongest storms expected to spread east into the Ark-La-Miss area through the evening and the threat possibly continuing overnight into western Tennessee and western Kentucky.
Nov. 3 is Election Day in the 2026 U.S. midterm elections. According to USA Today's summary of National Weather Service forecasts, northern California will see rain on Election Day, with the weather service's Bay Area office forecasting 0.10 to 0.50 inch in the North Bay and possible evening thunderstorms; southeast Florida still faces a threat of heavy rainfall, while most of the rest of the West stays sunny to partly cloudy.
(Source: NOAA Storm Prediction Center)
来源：美国国家气象局风暴预测中心
发布：GSM·美国（发布链接）
图片来源：图：超级单体雷暴笼罩 Kansas 一处农场上空（美国国家海洋和大气管理局国家强风暴实验室供图，公共领域）。 / A supercell thunderstorm over a farm in Kansas (NOAA National Severe Storms Laboratory, public domain).
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