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National Weather Service U.S. forecasters warned Thanksgiving travelers to be wary and expect delays as two powerful storms hit the West Coast within this week. These back-to-back weather disturbances will bring hurricane-force winds, blizzard conditions, heavy snowfall, as well as a "bomb cyclone" on western and central areas of United States.

On Tuesday night, snowstorm has already hit the mountain areas of southern Oregon and Northern California, with high waves and strong winds striking coastal areas in the far West, since the disturbance is coming from the Pacific Ocean. The record-setting storm system has turned into a bomb cyclone which means the storm intensified at an unusually rapid rate.

NWS said on Tuesday that the low pressure system will likely undergo bombogenesis (pressure drop of at least 24mb in 24 hours) at which point is expected to become a sub-980 mb low with hurricane force winds over the offshore waters.

NWS Weather Prediction Center said that wind gusts are forecast to exceed 70 mph near the coast of Oregon and Northern California. By late Thursday, 2 to 4 feet of snow will cover the Sierra Nevada range.

The forecast map of the NWS has reflected winter storm warnings raised from California to Michigan. Meanwhile, NWS office in Las Vegas winter storm warning posted 5 p.m. PT Tuesday will remain in effect until 4 a.m. PT Friday.

Moreover, heavy snowfall brought by the winter storm is already experienced by Denver and other cities in the southern and central Plains region. Snow in Cheyenne, Wyoming has already reached 12 inches of snow by midday on Tuesday, while in elevated areas west of Fort Collins, Colorado, snow is reported to have reached more than 30 inches.

NWS forecasters further noted that the winter storm is expected to carry a foot of snow in a broad region by Thursday while it moves towards the upper Mississippi Valley from the Plains, across the upper Great Lakes and into northern Maine.

In a report by CNBC, thousands of air traveler have been stranded in Denver Airport as Southwest Airlines canceled about 200 of its flights. Meanwhile, the agency warned those who will fly from San Francisco to Los Angeles and from Las Vegas to Phoenix to also expect delayed flights caused by strong winds, heavy rain and snow.

NWS also recommended drivers to take chains if they're moving through areas that might experience heavy snow.

Residents of coastal Southern California from San Diego to Los Angeles especially those who live in areas that have recently suffered wildfires, were warned of flash floods as the storm marched inland from the West Coast.

Compared to the turbulent weather conditions in the West Coast, the weather conditions on most of the East Coast remain relatively quiet, according to NWS. But the agency warns that strong winds will start to affect parts of the Northeast after the main storm marches off the coast of New England. NWS further warned that the wind gusts up to 40+ mph could pose a possible threat to the famous Thanksgiving Day parade in New York City.