Eastern US braces for "Frankenstorm" Sandy's strike

NOAA's GOES-13 satellite captured this image of Hurricane Sandy Oct. 28. The line of clouds from the Gulf of Mexico north are associated with the cold front with which Sandy is merging; the western cloud edge is already over the mid-Atlantic and northeastern US. Credit: NASA GOES Project.

Our readers along the East Coast of the US are in the path of Sandy, a storm expected to cause considerable rainfall, flooding, and high winds, with correspondingly high risk for property, structures, and life in more vulnerable areas. Sandy is now the largest tropical cyclone on record, with a radius of 520 nautical miles. The biggest threat? Too much water.

Turn off the breathless cable news coverage and instead read the reports from Dr. Jeff Masters, co-founder of Weather Underground. Snip:

Massive and dangerous Hurricane Sandy has grown to record size as it barrels northeastwards along the North Carolina coast at 10 mph. At 8 am EDT, Sandy's tropical storm-force winds extended northeastwards 520 miles from the center, and twelve-foot high seas covered a diameter of ocean 1,030 miles across. Since records of storm size began in 1988, no tropical storm or hurricane has been larger (though Hurricane Olga of 2001 had a larger 690 mile radius of tropical storm-force winds when it was a subtropical storm near Bermuda.) Sandy has put an colossal volume of ocean water in motion with its widespread and powerful winds, and the hurricane's massive storm surge is already impacting the coast. A 2' storm surge has been recorded at numerous locations this morning from Virginia to Connecticut, including a 3' surge at Virginia's Chesapeake Bay Bridge Tunnel and Sewells Point at 9 am EDT. Huge, 10 - 15 foot-high battering waves on top of the storm surge have washed over Highway 12 connecting North Carolina's Outer Banks to the mainland at South Nags Head this morning. The highway is now impassable, and has been closed. The coast guard station on Cape Hatteras, NC, recorded sustained winds of 50 mph, gusting to 61 mph, at 5:53 am EDT this morning. In Delaware, the coastal highway Route 1 between Dewey Beach and Bethany Beach has been closed due to high water. Even though Sandy is a minimal Category 1 hurricane, its storm surge is extremely dangerous, and if you are in a low-lying area that is asked to evacuate, I strongly recommend that you leave.

Much more here at Weather Underground, including anticipated rainfall charts.

His colleague Bryan Norcross, Hurricane Specialist at The Weather Channel, says Sandy is "serious as a heart attack."

The ocean will rise along the coast as Sandy makes it's way north, but the biggest coastal problems will come when the center makes landfall. We're unlikely to know exactly where that will be until Monday, but this is critical. The ocean will be pushed toward the coast north of that point and away to the south. The onshore flow of water is exaggerated where bays, inlets, or the shape of the coastline focus the water to make it rise even higher. The most prominent problem spot is New York City, where Long Island and New Jersey make an "L".

Raritan Bay and New York Bay and the south end of Manhattan are especially susceptible to rising water if the center of Sandy comes ashore in New Jersey or south. Much as we saw in Irene, it is potentially a monstrous problem due to the threat to NYC infrastructure and transportation. There are tough decisions ahead for the Mayor and his people.

Right now, the odds favor that southern track. The threat from this situation is serious as a heart attack for anybody near the rising water.

Then there's the wind which is expected to be MUCH higher than Irene at the skyscraper level. The city will also have to be thinking about the threat to people in tall buildings.

NYC mayor Michael Bloomberg has announced emergency shelter plans, and news that subways and MTA buses will shut down ahead of the storm's expected landfall.

Our readers in New York City would do well to follow our friend Scott Beale, who has been tweeting and blogging resources and updates.

Here's a NASA video of the hurricane approaching, as seen from a NOAA sattelite. And at the Atlantic, Alexis Madrigal explains with four simple graphics why Sandy has meteorologists scared.

Below, a photo from NOAA's GOES-13 satellite. Check out how much of the *planet* Sandy covers right now. This storm ain't no joke.