This is the official blog for Bryan Norcross, Hurricane Specialist at The Weather Channel.
By: Bryan Norcross , 4:05 AM GMT on October 27, 2012
It's one of the ugliest looking hurricanes you'll see, but Hurricane Hunters and satellite measurements confirm that its still tropical enough to be a hurricane... and its on track to cause a pile of trouble.
Two atmospheric processes are counteracting each other at the moment. Strong upper winds are trying to tear the storm apart, but a split in the upper flow is causing, essentially, a strong suction from above which is helping the storm keep going. This situation will likely result in some weakening... which would mean Sandy would drop below hurricane strength. But then the polar jet stream takes over and re-energizes the storm increasing the winds and growing the size. A sharp dip in the jet stream will pick up the reinvigorated Sandy and swing it toward the East Coast. At least that's the plan.
There are some ifs and maybes in that scenario, but the best computer forecast models independently insist that this is what's going to happen... and the not-so-reliable ones say the same thing. So, beginning immediately, it comes down to figuring out how to deal with it.
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.
The winds... expected to be at or near hurricane strength at landfall... will spread inland for hundreds of miles either side of the storm center. It's hard to imagine how millions of people are not going to be without power for an extended period of time.
Widespread rainfall of 3 to 7 inches with some places getting a foot or more will cause extremely dangerous flash flooding.
And then there's the snow. Heavy wet snow is forecast for the mountains of West Virginia and southwest Pennsylvania, mixed with rain at the lower elevations.
The winds will increase Sunday night in the Tidewater of Virginia and spread north through the day on Monday. The best guess right now is that the peak winds will come in overnight Monday night... near high tide and under a full, flooding moon. A triple whammy.
Let me think, what other disastrous thing might happen. It's storm overload, I know... and nobody likes to think about these kinds of things. Nothing here is certain, of course, just becoming more likely with every new piece of data. But one thing is for sure... if this all happens as forecast, and you and your family are stuck in the cold and dark without food and light and communications because you didn't run to the store and get ready... excuses are going to spectacularly hard to come by.
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