着感恩节临近，迫使成千上万美国人推迟或取消假日旅行的恶劣天气再次威胁到航空旅行和驾驶条件，这一次是数百万度假回家的旅客。
据估计，在感恩节前后的12天里，共有3160万名乘客乘坐飞机，周日被预测为美国航空旅行有史以来最繁忙的一天，美国工业贸易集团航空公司预测有310万名乘客。然而，这一记录可能不会被打破，因为大风、低能见度、冰雪可能会使飞机在全国各地停飞。
感恩节那天席卷西部的冬季风暴已经向东移动。截至周六上午8点，美国国家气象局已经向中西部北部地区的每个县发布了冬季风暴警报和冬季天气预报，从蒙大拿州西部到密歇根东部，系统覆盖了五大湖，到达宾夕法尼亚州和纽约。与此同时，洪水和风暴警报向南延伸至德克萨斯州和墨西哥湾沿岸。
根据芝加哥航空部门的数据，周六早上中西部枢纽的旅行中断最小，平均延误不到15分钟，芝加哥奥黑尔国际机场3000多个航班中只有18个在过去24小时内被取消。底特律地铁机场和明尼阿波利斯圣保罗机场的空中交通也同样顺畅，但这些情况预计会在当天晚些时候发生变化。
“今天和今晚，预计低雪和大雪将在北部/中部平原和上密西西比河流域蔓延，并于周日结束。美国国家气象局天气预报中心周六早些时候报道说，预计从北部平原到明尼苏达州、威斯康星州和上密歇根，将会有6到12英寸的大范围降雪，当地的降雪可能会超过18英寸。“预计会有大风，暴风雪警告在北部/中部平原的部分地区生效。危险的条件将使旅行几乎不可能。大雪影响以南的中部/南部平原实施大风警告和风力警报。”
暴风雪警报在周日早上生效，覆盖了北部高原的一部分和苏必利尔湖的西端。州际公路90和35穿过这些地区。旅行可能非常困难。大面积降雪会显著降低能见度。
—国家气象局(@NWS)2019年11月30日
随着周日风暴系统转移到东海岸，国家气象局预测又一轮东北风:
“冻雨将是宾夕法尼亚和纽约部分地区以及阿巴拉契亚中部的最初威胁...从纽约、佛蒙特州南部、新罕布什尔州和马萨诸塞州的部分地区到周日晚上，东北部的降雪量预计为4到8英寸，预计周一会有更多降雪。在这个繁忙的旅游周末，旅游影响是可以预料的。”
与此同时，在加利福尼亚形成的一个新风暴系统有可能在低海拔地区引发洪水，在高海拔地区引发大雪。据气象频道报道，导致车辆失控的结冰路况导致北加州5号公路沿线100多英里的公路关闭，而大雪和冰迫使亚利桑那州的一个城镇在本周早些时候宣布进入紧急状态。
MAJOR STORM THREATENS BUSIEST TRAVEL WEEKEND OF THE YEAR
As Thanksgiving week draws to a close, the severe weather that forced thousands of Americans to delay or cancel their holiday travel once again threatens to impact air travel and driving conditions, this time for millions of travelers heading home from the holidays.
With an estimated 31.6 million passengers flying during the 12-day period around Thanksgiving, Sunday has been forecast as the busiest day ever recorded for U.S. air travel, with industry trade group Airlines for America predicting 3.1 million passengers. That record might not be broken, however, as high winds, low visibility, ice and snow are likely to keep planes grounded across the country.
The winter storm that wrecked havoc out west on Thanksgiving Day has since moved east. As of Saturday at 8 a.m. CST, the National Weather Service had issued Winter Storm Warnings and Winter Weather Advisories for every county along the northern band of the Midwest, from western Montana and eastern Michigan, with the system reaching across the Great Lakes into Pennsylvania and New York. Meanwhile, flood and storm warnings extended south all the way to Texas and the Gulf Coast.
Travel interruptions were minimal at Midwestern hubs Saturday morning, with average delays under 15 minutes and only 18 out of over 3,000 flights canceled in the last 24 hours at Chicago O'Hare International Airport, according to the Chicago Department of Aviation. Air traffic was similarly smooth out of Detroit Metro Airport and Minneapolis-St. Paul Airport, but those conditions were expected to change later in the day.
"North of the low, heavy snow is forecast to spread across the Northern/Central Plains and Upper Mississippi Valley today and tonight, ending there on Sunday. A large swath of snow totals from 6 to 12 inches are expected from the Northern Plains into Minnesota, Wisconsin, and Upper Michigan, and locally higher snow amounts above 18 inches are possible," the National Weather Service's Weather Prediction Center reported early Saturday. "High winds are expected, and Blizzard Warnings are in effect for parts of the Northern/Central Plains. Dangerous conditions will make travel almost impossible. High Wind Warnings and Wind Advisories are in effect for the Central/Southern Plains, south of the snow impacts."
Blizzard Warnings are in effect into Sunday morning across a portion of the northern High Plains and the west end of Lake Superior. Interstates 90 and 35 pass through these areas. Travel could be very difficult. Widespread blowing snow could significantly reduce visibility.
— National Weather Service (@NWS) November 30, 2019
As the storm system moved onto the East Coast Sunday, the National Weather Service predicted another round of nor'easters:
"Freezing rain will be the initial threat for portions of Pennsylvania and New York, as well as the Central Appalachians...Snowfall amounts in the Northeast are currently forecast to be 4 to 8 inches from parts of New York, southern Vermont and New Hampshire, and Massachusetts through Sunday night, with more expected on Monday. Travel impacts can be expected on this busy travel weekend."
Meanwhile, a new storm system forming over California threatened to cause flooding at lower elevations and heavy snowfall in higher areas. Icy road conditions leading to vehicle spin-outs previously caused over 100 miles of highway closures along Route 5 in Northern California, while heavy snow and ice forced one Arizona town to declare a state of emergency earlier in the week, The Weather Channel reported.
