While flooding is likely to be minor and sporadic through Friday, the warmup and rainfall will continue to bring the risk of leaky roofs and roof collapses into the weekend.
This risk is greatest on flat roofs.
"A deep snow varied by drifting, combined with rainfall, natural melting and blocked drainage systems on the roofs can lead to uneven weight distribution," According to Forensic Weather Expert Steve Wistar, "When this weight exceeds the design of the roof, a partial or total collapse could occur."
Property owners may want to consider removing some of the snow from the roof, only if they can do so safely. If any doubt, consult a properly-insured private contractor.
In some cases, strained roofs that survive the added weight from this week's rain could succumb to additional storms later this season.
A collapsed resort building is seen in Gyeongju, South Korea, Tuesday, Feb. 18, 2014. The roof of the resort auditorium collapsed during a welcoming ceremony for South Korean university freshmen, killing nine and likely trapping about 10, officials said Tuesday. (AP Photo/Yonhap, Lee Jae-hyuck)
Cold air is expected to return in stages this weekend, and additional storms with heavy snow are possible beginning next week. The return of cold air will cause slush and runoff to freeze.
The lingering snow cover and added moisture from the rainfall and additional snowstorms will carry the flooding forward through the remainder of the winter and perhaps into the spring.
As of Tuesday, Feb., 18, 2014, there was as much as 6 inches of water locked up in the snow over parts of the Upper Midwest and northern New England. Farther south in the Midwest and Northeast, there was between 1 and 3 inches of water contained within the snow on the ground.
Over a surface area of one square foot, an inch of water (approximately 10 inches of snow on average) weighs about 5.2 pounds. However, the weight of the snow can vary, depending on its water content when it first fell and how much rain it absorbed later.
Steve Wistar is one of the nation's leading experts on roof snow loads.
Another round of rain is expected to move through the Carolinas on Saturday, which may lead to rises on some small streams and creeks.
A strengthening storm system will bring the threat for flooding, mudslides and severe thunderstorms to areas from Italy into the Balkans later Friday into the 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 "blob" of abnormally cold water in the North Atlantic, located near Greenland, has the potential to put enough drag on the ocean current to impact weather conditions in the years to come.
“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.
Cool weekend weather is in store for the Northeast after rain and thunderstorms dampen the region on Friday.
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.