Mega-storm Sandy

[Lonestar]

Das Compost

Mega-storm threat growing for mid-Atlantic and Northeast early next week from hurricane Sandy
By Jason Samenow


There is a consensus forming in weather forecast models that hurricane Sandy is unlikely to go out to sea. Instead, it more likely will merge with a strong fall cold front and transition into a powerhouse, possibly historic mid-latitude storm along the mid-Atlantic and/or Northeast coast Sunday through Wednesday.

The majority of models now take Sandy from its current position over Jamaica northward over the Bahamas before curving the storm towards either the mid-Atlantic or Northeast coast. Models disagree on where the storm will recurve and make landfall: simulations vary from the mid-Atlantic to Maine. There remains a chance, though diminishing, the storm will slide harmlessly out to sea.



The location of the storm’s landfall is very important for determining exactly what local impacts will be. Not everyone will experience significant or dangerous storm conditions. But suffice to say, coastal regions from the Carolinas through eastern Canada are likely to get battered by tremendous surf and face a real risk of significant to severe coastal flooding. This storm will be a slow mover meaning large waves may pound the coast for lengthy time periods. Not to mention, the wind and waves will raise the water level, bringing ashore a multiple foot storm surge in regions close to where the storm makes landfall (assuming it does so).

Making matters worse, the storm will coincide with a full moon Monday night, meaning elevated tides above normal levels. Astronomically high tides have played a key role in historic coastal flooding events along the East Coast, such as the Ash Wednesday storm of March, 1962.

Inland areas in the mid-Atlantic and Northeast, from Richmond to Washington, D.C. to New York City to Boston, may also deal with significant storm impacts. Heavy rains are possible along with punishing winds. But the track is key in determining exactly where and we cannot say which areas, if any, will experience these conditions.

As a hurricane transitions into a mid-latitude weather system, the storm’s core tends to unwind. This means the most extreme winds around the storm’s center diminish some, but very strong winds spread out over a larger distance, affecting a much broader region. In other words, sustained winds above tropical storm force (39 mph) will be possible for locations well-displaced from the storm’s center, meaning a high power outage risk.

Severe inland flooding is another possibility. But again, it’s impossible to pinpoint if/where this will occur. Recall that the inland flooding - as opposed to wind or storm surge - was the greatest cause of death and economic damage during hurricane Irene in 2011 bringing torrents to upstate New York and Vermont.

Finally, snow may be an issue at high elevation in the interior mid-Atlantic and Northeast as cold air pours down on the storm’s west and southwest flank. Some models suggest over a foot of heavy, wet snow could fall in places like western Maryland and central and western Pennsylvania. This amount of snow on top of existing foliage could result in tremendous tree damage and power outages.

Snow is much less likely at lower elevations as the storm wraps around some mild air from the tropics. However, it cannot be ruled out briefly towards the tail end of the storm as tropical air departs and cold air wins

Why is the storm unlikely to go out to sea?


It’s actually pretty simple: a traffic jam in the atmosphere’s flow probably won’t let it. Models are consistent in showing a “blocking” area of high pressure west of Greenland and a big ocean storm to its east. These features are likely to prevent the big incoming cold front from pushing Sandy out to sea. The North Atlantic Oscillation - a measure of this “block” in the flow, is forecast to be three standard deviations from the average- meaning this is an exceptional situation. Thus, the storm is favored to be forced north rather than going east out to sea (although I stress this still cannot be ruled out)

As NOAA’s Hydrometeorological Prediction Center writes:

“THERE IS INCREASING CONSENSUS AMONG THE GUIDANCE FROM THE VARIOUS MODELING CENTERS... THE ENTIRE ATLANTIC BASIN SEEMS DESTINED TO BECOME DOMINATED BY BLOCKY HIGHS AND LOWS, WITH DECREASING WIGGLE ROOM FOR EVEN LARGE FEATURES LIKE SANDY. ”

Round-up of voices/opinions about this storm

Jeff Masters, wunderground: “Sandy: a potential billion-dollar storm for the mid-Atlantic and New England”

Dr. Greg Forbes, the Weather Channel: “A worst-case scenario of Hurricane Sandy or some hybrid (mixed with a cold front and jet stream system coming toward it) could bring a widespread destructive windstorm to some part of the Northeast from Sunday into early next week. Prior to then, heavy rain, strong gusty winds, large waves and maybe storm surge are possible for coastal areas from FL to NJ.”

Bryan Norcross, the Weather Channel: “....it’s not often that credible forecast models consistently forecast a historic event, and with more models leaning that way, we need to be aware and pay attention along the entire U.S. East Coast.”

Joe Lundberg, AccuWeather: “....the evidence seems to be mounting toward the convergence of these two weather systems into an historic storm early next week.”

Alex Sosnowski, AccuWeather: “The realm of possibilities continues to range from Sandy escaping out to sea, with nothing more than blustery, much cooler air sweeping in, to a dynamic storm turning inland packing coastal flooding, flooding rainfall, high winds, downed trees, power outages, travel mayhem and even Appalachian snow.”

Stock up on Ramen and ammo.

[Esquire]

Well, fuck. You know what's between DC and the ocean? Where I live.

[Simon_Jester]

Man I gotta pay you a visit sometime, Esquire.

I wonder when we'll have an idea of when it makes landfall.

[Skywalker_T-65]

Suddenly I'm thankful I live in the Mid-West...

Good luck to anyone who does live in the path, whenever it does make landfall.

[TimothyC]

Man I gotta pay you a visit sometime, Esquire.

I wonder when we'll have an idea of when it makes landfall.

Sunday-Wednesday of next week.

[Simon_Jester]

Well, I'm still hoping for time of day and a bit more precision, if it's going to hit me.

[Col. Crackpot]

Looks like it should hook west at some point and make a beeline for New England. This should be fun.

[Tsyroc]

Every time I see the topic title I think DC comics is getting ready for some new cross-over event called Megastorm.

[Alferd Packer]

I'm pretty sure that's aimed squarely at my house right now. Which side of the storm is worse to be on? East or west?

[Ahriman238]

I'm pretty sure that's aimed squarely at my house right now. Which side of the storm is worse to be on? East or west?

Doesn't make any real difference.

Looks like I'm getting it in the shorts to. On the bright side, I work in the only school in New England that sometimes closes for heavy rain. Looks like a work break anyway.

Seriously, I should be alright. Everyone else in the path, stay safe.

[Broomstick]

With a storm like that, as noted in the graphic, hazardous conditions can exist outside that projection cone.

I think I heard in passing this morning it made landfall in the islands today with sustained winds in the 110 mph/175 kph range. That's nothing to sneeze at, and means that triple-digit (metric) windspeeds will extend outwards from the storm itself for very large distances.

I fully expect that my father and sister living in western New York will see some significant storm weather if it follows that track, even if they don't get the most serious weather. My nephew in Manhattan and niece in Boston are going to get direct hits. Think I'll mention to my sister to remind them to take out some cash in cash of power failure as, you know, the kids these days, they do everything on-line or with ATM's. If the power's out neither of those work too well.

[Beowulf]

I'm pretty sure that's aimed squarely at my house right now. Which side of the storm is worse to be on? East or west?

Conditions tend to be worse in the right front quadrant of the storm. That said, the interaction with the cold front is likely to cause things to be out of the ordinary.

[Terralthra]

Every time I see the topic title I think DC comics is getting ready for some new cross-over event called Megastorm.

Same. Looks like my family in Pittsburgh will avoid the worst of it, if it follows the predicted track.

[FSTargetDrone]

I'm pretty much in the middle of the projection over Pennsylvania, just a bit southwest of the "S" in the circle (39-73mph winds is plenty, thanks). Should be interesting. With Irene last year, I spent the whole night patrolling the 2 floors of the apartment here checking for leaks. Had some localized flooding when the Schuylkill went over its banks and covered a few roads.

[phred]

I had an argument with a guy from florida a couple weeks ago over whether earthquakes or hurricanes are better to deal with. I said I would take a serious quake every 10 years or so over hurricanes every year. He hasn't been on the last couple days. Hope he's ok.

Good luck to you guys too.

[Lord of the Abyss]

Every time I see the topic title I think DC comics is getting ready for some new cross-over event called Megastorm.

That was my first thought upon seeing the title as well.

After opening the thread, my next thought was "How long before some right wing preacher blames it on gays or Obama?" Gays are more traditional, but since it's headed at DC they might go for Obama instead. Or both.

[FireNexus]

I work for the electric company in Philadelphia, and they've told us we're all working 12-16 hour shifts pretty much all next week. Should be interesting.

[General Zod]

Long Island should expect to feel the start of the storm late Sunday night with wind gusts of 40 to 50 miles per hour, Stark said. By Monday evening, sustained wind gusts will reach between 60 and 80 miles per hour, he said. A hurricane is labeled as sustained wind gusts of 74 miles per hour, Stark said.

Goody. I guess it's a good thing I moved to a place in the Bronx before it hits. I imagine Staten Island is going to get it pretty rough.

[Col. Crackpot]

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* CAPE FEAR TO DUCK NORTH CAROLINA
* PAMLICO AND ALBEMARLE SOUNDS
* BERMUDA

IN ADDITION...HURRICANE-FORCE WINDS ARE EXPECTED ALONG PORTIONS OF
THE COAST BETWEEN CHINCOTEAGUE VIRGINIA AND CHATHAM MASSACHUSETTS.
THIS INCLUDES THE MIDDLE AND UPPER CHESAPEAKE BAY...DELAWARE
BAY...AND THE COASTS OF THE NORTHERN DELMARVA PENINSULA...NEW
JERSEY...THE NEW YORK CITY AREA...LONG ISLAND...CONNECTICUT...AND
RHODE ISLAND.

TROPICAL-STORM-FORCE WINDS ARE EXPECTED NORTH OF CHATHAM TO
MERRIMACK RIVER MASSACHUSETTS...THE LOWER CHESAPEAKE BAY...AND
SOUTH OF CHINCOTEAGUE TO DUCK NORTH CAROLINA...THE NORTHERN
ENDPOINT OF THE TROPICAL STORM WARNING.

OTHER COASTAL AND INLAND WATCHES AND WARNINGS ARE IN EFFECT FOR
THESE AREAS. PLEASE SEE STATEMENTS FROM LOCAL NATIONAL WEATHER
SERVICE FORECAST OFFICES.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.

National Hurricane Center

Hurricane force winds stretching from Virginia to Massachusetts at landfall. Holy. Fucking. Shit.

[Dartzap]

I was just wondering about the NYC underground system - does it have airlocks to keep it dry should the flood defences get breached? Would knacker a fair bit of infrastructure underground if it goes under a few feet of salt water.

Good luck to all those about to be hit.

[General Zod]

I was just wondering about the NYC underground system - does it have airlocks to keep it dry should the flood defences get breached? Would knacker a fair bit of infrastructure underground if it goes under a few feet of salt water.

Good luck to all those about to be hit.

http://en.wikipedia.org/wiki/New_York_C ... y_flooding

[Dartzap]

One hopes they are prepared for more than three inches, heh

[FSTargetDrone]

Weather is saying 6 inches for my area tomorrow. The rain is just now beginning to fall steadily...

[Col. Crackpot]

One hopes they are prepared for more than three inches, heh

I'd be more concerned with the 11 foot storm surge washing over battery park.

[Lonestar]

Federal Government is closed tomorrow. Got a text from my boss saying I'm a mission essential employee and my ass better open up the NOC tonight.


So, yay, I guess?