UPDATE (11 p.m. Saturday Local Time):
Usagi's threat to Taiwan is weakening as the storm moves towards Hong Kong for the second half of the weekend. Additional details about the new threat can be found here.
Usagi remains a super typhoon with winds of 150 mph as it barrels toward Taiwan, followed by Southeast China.
Maximum sustained winds of 160 mph were registered with Usagi Thursday night local time (Thursday EDT), making the dangerous storm a super typhoon.
A super typhoon is equivalent to a strong Category 4 or 5 hurricane in the Atlantic with maximum sustained winds of at least 150 mph.
However, Usagi weakened slightly Saturday, to a typhoon as it passed to the south of Taiwan. Still, the storm remains a very dangerous and potentially deadly tropical system.
This satellite image of Usagi, courtesy of NOAA, was taken Friday night local time.
The mountainous terrain of Taiwan will slightly weaken Usagi as it approaches the island, but Usagi will still be a powerful typhoon when it makes its closest approach to far-southern Taiwan Saturday local time.
Friday night conditions will deteriorate across Taiwan as wind and rain increase and the threat of coastal flooding along the eastern coast heightens.
Wind gusts as high as 120 mph threaten to cause widespread destruction across far-southern Taiwan Saturday. Such winds can lead to major damage of homes and snap or uproot many trees. Residents should prepare for lengthy power outages.
Gusts ranging from 80 to 120 mph are expected elsewhere across southern Taiwan. Winds on the higher end of this range are most likely over southeastern Taiwan.
Adding to the concern for loss of lives and property will be a devastating storm surge of 10 to 18 feet along the southeastern coast, while torrential rain also inundates Taiwan.
"Rainfall can easily total a foot in coastal areas on the south and southeast side of the island, and the mountains in the southern half of Taiwan could receive between 20 and 30 inches," stated AccuWeather.com Meteorologist Eric Wanenchak.
That amount of rain is sure to cause life-threatening flooding and mudslides.
The worst of the storm will pass south of Taipei; however, some of Usagi's outer drenching and squally rain bands will spread across the city through Saturday. Wind gusts could occasionally reach 40 mph.
Rain totals will likely be between 2 and 4 inches, heightening concerns for urban flash flooding. Most of that rain will come before Usagi's center reaches far-southern Taiwan.
The Philippines will also be spared from the worst of Usagi, but flooding rain and gusty winds will continue to affect northern Luzon through Saturday.
Flooding will actually become a concern in the capital city of Manila this weekend and into early next week as Usagi passes to the west of the Philippines and moisture from the typhoon and what was once-Tropical Depression 18W is drawn into the city.
This type of setup during previous tropical systems has led to massive flooding in Manila.
After battering Taiwan, Usagi will take aim at Southeast China with an eventual landfall very close to Hong Kong Sunday afternoon or Sunday night. Usagi could still be a Category 2 or 3 hurricane as it nears Southeast China.
Areas from Zhanjiang to Hong Kong northward to Zhangzhou should closely monitor this storm as the potential for flooding rainfall, damaging winds and coastal flooding exists Sunday into Monday.
Senior Meteorologist Kristina Pydynowski contributed to this story.
Joaquin continues its journey across the northern Atlantic toward Europe, where it is expected to impact Spain and Portugal this weekend.
Winter will kick off with mild weather in the Northeast and mid-Atlantic as an intensifying El Nino influences the weather pattern across the country.
A fall-like weekend is in store for the Northeast, after rain and thunderstorms will dampen the region on Friday.
Another round of rain is expected to move through the Carolinas on Saturday, which may lead to rises on some small streams and creeks.
Oho will hit parts of British Columbia and Alaska with drenching rain, gusty winds and pounding seas before the week comes to an end.
“It was by far the most intimidating natural disaster I have ever chased,” Storm Chaser and Extreme Meteorologist Reed Timmer said of the historic flooding in South Carolina.
San Antonio, TX (2000)
A high temperature of 45 degrees (the average high on this date is 84 degrees).
New England (1804)
Extraordinary "Snow Hurricane" - snow mixed with heavy rains from Washington, D.C. on north - heavy snow in interior New England. Up to 2 feet in Green Mountains of Vermont.
A few snow flakes in Philadelphia, PA (trace). Also a trace of snow in Baltimore, MD.