冬季风暴警告生效：加州 Sierra 高海拔地区总降雪可达20英寸
美国国家气象局 Hanford 办公室11月13日晚10时04分发布的预报讨论显示，加州 Sierra Nevada 山区冬季风暴警告持续生效至周二（11月17日）凌晨4时，海拔6,000英尺以上地区本轮总降雪量可达20英寸，山区出行条件恶劣。
这轮系统已经给当地带来明显降水：San Joaquin Valley 多地降雨多达0.5英寸，Sierra 与山麓地带降水0.50至1.50英寸，山区与沙漠地带阵风约50英里/时。气象局同时发布的大风警告有效至周六早晨7时，湖面大风警告有效至周六上午10时。
这还不是本周唯一一轮风暴。下一轮系统将于周日夜间至周一抵达，再下一轮在周三至周四到来，届时雪线可降至约5,000英尺，Grapevine 与 Tehachapi 等山口路段需要特别留意。
从概率看，周日夜间至周一，谷地降雨达到0.50英寸的概率为30%至40%，Sierra 达到1英寸的概率为40%至50%，其中 Madera、Mariposa 一带可达70%至80%。气候预测中心的6至10天展望也显示，该地区同期降水偏多的概率为40%至50%。
气象局提醒，计划进入山区的车辆应备好防滑链并预留充足时间，出行前查看最新路况与预报更新。
（来源：美国国家气象局）
Winter Storm Warning: Up to 20 Inches of Snow Expected Above 6,000 Feet in California's Sierra Nevada
In a forecast discussion issued at 10:04 p.m. PST on November 13, the National Weather Service office in Hanford, California, said a Winter Storm Warning remains in effect for the Sierra Nevada through 4 a.m. Tuesday (November 17), with total snowfall of up to 20 inches expected above 6,000 feet and difficult mountain travel.
The current system has already delivered significant precipitation: up to 0.5 inch of rain in parts of the San Joaquin Valley, 0.50 to 1.50 inches in the Sierra and foothills, and gusts near 50 mph in the mountains and desert. A Wind Advisory runs until 7 a.m. Saturday, and a Lake Wind Advisory until 10 a.m. Saturday.
More systems are on the way. The next arrives Sunday night into Monday, and another follows Wednesday into Thursday, when snow levels may drop to about 5,000 feet by Thursday morning, with the Grapevine and Tehachapi passes among the areas to watch.
For Sunday night into Monday, the probability of at least 0.50 inch of rain in the valley is 30 to 40 percent, and of at least 1 inch in the Sierra 40 to 50 percent, rising to 70 to 80 percent around Madera and Mariposa. The Climate Prediction Center's 6-to-10-day outlook also gives the region a 40 to 50 percent chance of above-average precipitation.
The Weather Service advises drivers heading into the mountains to carry tire chains, allow extra time, and check the latest road conditions and forecast updates before setting out.
(Source: National Weather Service)
来源：美国国家气象局
发布：GSM·美国（发布链接）
图片来源：图片来源：Wikimedia Commons，Shaggywoody 摄「CA Highway 4 at Bear Valley Jan. 23, 2010」（公共领域），图中为加州 Sierra Nevada 山区 Bear Valley 一带风暴过后的雪景（原图底部时间戳已裁去） Image: Wikimedia Commons, "CA Highway 4 at Bear Valley Jan. 23, 2010" by Shaggywoody (public domain), showing snow near Bear Valley in California's Sierra Nevada after a January storm (timestamp at bottom cropped)
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