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The Board Is Set; The Pieces Are Moving

October 28th, 2012 - 10:32 am

[NOTE: For my latest updates on Hurricane Sandy, follow me on Twitter.]

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Hurricane Sandy’s barometric pressure dropped from 960 millibars at 5am EDT to 951mb at 8am, and new convection is appearing around the center. The lessening of wind shear, and the influence of the warm Gulf Stream waters underneath Sandy, are having the expected effect: deepening of the low pressure at the storm’s core. Meanwhile, the wind field continues to expand, to historic proportions. Sandy is now the largest hurricane in Atlantic history, with its tropical storm-force winds having a diameter of more than 1,000 miles!

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The computer models continue to forecast this storm remarkably well, particularly given its uniqueness and complexity, and there’s really no reason at this point to doubt the remainder of their prediction: Sandy will keep getting better organized today, will “bomb out” tomorrow — not long before landfall — into a monster storm with possibly record-low pressures for the Northeast/mid-Atlantic, will hang a sharp left turn into New Jersey, and will bring a huge, devastating, life-threatening, wind-driven storm surge (worsened by extremely high surf and astronomical high tide) into Long Island Sound, New York Harbor, the south shore of Long Island and the Jersey Shore. Coastal damage will be extensive. Wind damage will also be severe, including well inland, due to the sustained battering and the possibility of unusually extreme gusts due to PV towers and tropopause folds. Property losses will be extraordinary. Loss of life is probable if people do not take this storm very, very seriously.

After making landfall, Sandy will finish its transition to an extratropical (but still-powerful) storm, and will dump heavy snow on portions of West Virginia and Pennsylvania. Elsewhere, it will dump heavy rain, producing inland flooding in some areas (though it probably will not be as bad as the devastating inland floods from Irene, because the ground is less saturated). Millions will lose power, many through Election Day and beyond.

If you’re in an impacted region, today is your last day to prepare. By tonight, weather conditions will already be deteriorating. So, as the weather service always says at times like these, “Preparations to protect life and property should be rushed to completion.” (Preparedness links can be found at the bottom of this post.)

If you’re in a surge-vulnerable coastal area, you may need to leave. Listen to what local officials say about whether you should evacuate — unless you live in New York City, in which case you should ignore your foolish mayor and, if you live in Zone A or Zone B and are vulnerable to a possible surge of up to 10 feet, GET THE HELL OUT! (Criticism of Bloomberg’s bizarre, inaccurate press conference yesterday is damn near universal in the meteorological community. I’ve never seen anything like it.) Wherever you are, DO NOT STAY PUT, IGNORING EVACUATION ORDERS, SIMPLY BECAUSE YOUR HOME WAS FINE IN SOME PREVIOUS STORM. Every storm is different, and this storm will be historically bad in many places. If you’re ordered to leave — leave. If it’s even suggested by your local officials that you leave — leave. Do not risk it. It’s not worth it.

Beyond that, it’s difficult to think of new things to say about Sandy. Assuming the computer models — so accurate to this point — aren’t totally out to lunch, we basically know what the storm is going to do, and where its center will go (with the computer model forecast “envelope” now being essentially from South Jersey to North Jersey), and what its impacts will be. We’re now pretty much just waiting for it all to happen. The board is set; the pieces are moving.

Connecticut meteorologist Geoff Fox writes:

Hurricane Sandy is less than two days away. It is a major threat to our state. Don’t think that kind of weather doesn’t happen here, because it does and there’s every indication it will!

I am fearful. I suspect fear is now a common emotion in Connecticut. It is warranted.

What struck me today is how few surprises there were. Considering Hurricane Sandy has a structure like no other storm we’ve seen and is taking a path unlike any I’ve experienced, the computer guidance has been amazingly consistent.

Consistent model agreement implies the computers have properly latched onto Sandy’s salient features.

What’s come into sharper focus is the potential for shoreline flooding. If the guidance is right this will be a coastal inundation of historic proportions. The damage and destruction will be the most seen since the Hurricane of ’38, maybe more! …

Stay safe. Protect your family. Protect yourself. Be smart.

UPDATE: Bloomberg has ordered a Zone A evacuation in NYC, thank goodness. I’m still a bit concerned about Zone B, or at least parts of it. The water level at Battery Park is currently forecast to exceed 11 feet at its peak. That would break records.

More this evening. I intend to do a live tidal gauge / radar / satellite / wind gauge / etc. post, like I did with Irene and Isaac. That will go live sometime tonight. Stay tuned.

Get The Hell Out

October 27th, 2012 - 8:35 pm

[NOTE: This post was written and published Saturday night, 48 hours before New York City was inundated. It's now getting some retrospective attention, driven in part by my subsequent criticisms of Mayor Bloomberg (which this post proves are not based on unfair 20/20 hindsight). So I've tacked on a "POST-STORM UPDATE" to the end of this post, adding context, trying to fully elucidate my position, and explaining why the fact that Bloomberg did, finally, order a belated Zone A evacuation on Sunday isn't enough to insulate him from the criticisms I made on Saturday. Please read the post-storm update before you start an argument with me about how I'm wrong, because the update most likely addresses the point you were thinking of making. Better yet, instead of arguing with me, donate to the Red Cross. I'm going to go do that now.

And now, for the original post, as written Saturday...]

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Being up in Wyoming with my older girls, away from my computer, I have limited information about Sandy right now. But from what I’m seeing on Twitter, it appears: 1) the computer models indicate that the threat of a catastrophic storm surge in New York City has increased, and is a VERY real (though, of course, not certain) threat; and 2) Mayor Bloomberg has affirmatively decided NOT to evacuate even the most low-lying areas of his vulnerable city, nor even to close the city government or schools Monday.

If I have all of that right, it makes no damn sense at all.

Bloomberg’s error here could be even worse than that of Ray Nagin, who merely delayed too long, but who at least did ultimately give the obviously necessary evacuation order. It’s also hard to square Bloomberg’s inaction with his proactive — and correct — actions in advance of Irene. Perhaps he’s now gun-shy because of ignorant hindsight 20/20 criticisms of that “unnecessary” evacuation. If so, he’s a damn fool, along with those who criticized him then for an evacuation that was fully justified by contemporaneous information.

In any case, if I lived in a “Zone A” or “Zone B” area of NYC, I’d get the hell out, tonight. (Or tomorrow, if I could easily travel by foot to my non-flood-prone destination.) It’s not even a close call. Same goes for any other location in the cone of uncertainty that’s vulnerable to a potential (not certain–it’s never certain–but realistic potential) storm surge of 6-10 feet, plus very high surf on top of that, at astronomical high tide.

Ugh.

If I’m missing or misunderstanding something here, let me know. (For what it’s worth, I’m seeing plenty of meteorologists on Twitter saying the same thing. They’re baffled by Bloomberg’s decision. So am I.)

UPDATE: I’ve now seen and read Bloomberg’s statement. It’s even worse than I thought. He said:

We are not ordering any evacuations as of this time for any parts of the city. We’re making that decision based on the nature of this storm. Although we’re expecting a large surge of water, it is not expected to be a tropical storm or hurricane-type surge. With this storm, we’ll likely see a slow pileup of water rather than a sudden surge, which is what you would expect from a hurricane, and which we saw with Irene 14 months ago.

So it will be less dangerous – but make no mistake about it, there will be a lot of water and low-lying areas will experience flooding. The City’s Departments of Transportation and Environmental Protection will be deployed throughout the city to address flooding conditions.

Let me be clear: I have literally no f***ing idea what Bloomberg is talking about. As closely as I’ve been following Sandy, I have not seen anyone else — literally not a single meteorologist or any other person — suggest that Sandy will produce a “slow pile up of water” rather than a typical “sudden” storm surge. On the contrary, AccuWeather’s Mike Smith writes:

“So it will be less dangerous.” We don’t know that to be the case. The latest barometric pressure associated with Sandy is 960 mb. It is forecast to drop to 937 mb when it is south of NYC (see posting below from 11:40pm CDT). With a pressure that low the winds and surge could be very comparable to a hurricane. It would be an all-time record low for the region, hurricane or not.

All storm surges are, in their initial stages, somewhat slow, gradual pile-ups of water … which then rapidly peak when the storm’s center moves ashore. That’s exactly what’s to be expected here. Bloomberg’s idea of a uniquely slow drip-drip-drip surge doesn’t even make logical sense, and has no scientific basis that I’ve heard anyone articulate. Is he high? Has he lost is mind? I am simply stunned and baffled by this ignorant pronouncement, which will cause people to become complacent, and thus endanger lives.

Can New Jersey please annex New York City so we can get Chris Christie in there to fix this? Good lord.

Perhaps Bloomberg is confused by the National Hurricane Center’s hotly debated nomenclature decision to not use the terms “Hurricane Warning” and “Tropical Storm Warning” north of the Virginia/North Carolina border, choosing instead to use “High Wind Warning” because they expect Sandy to transition to an extratropical storm just before landfall — even though Sandy is a hurricane now and will be bringing hurricane-like conditions to the shore. (If you can’t tell, I disagree with the decision. Almost everyone in the meteorological and weather-nerd community seems to.)

Whatever Bloomberg’s rationale, he’s just absolutely dead wrong, as noted by The Weather Channel’s Jim Cantore and Bryan Norcross (who calls Bloomberg’s press conference “incomprehensibly inexplicable”), The Wall Street Journal’s Eric Holthaus, New York Fox 5′s Nick Gregory, WeatherBell’s Ryan Maue (“Bloomberg has baffled everyone with his bizarre press conference”), and many others.

Indeed, let me quote Norcross a little more extensively, to fully explain the problem here:

[Norcross & more after the jump.]

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[NOTE: For my latest updates on Hurricane Sandy, follow me on Twitter.]

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Hurricane Sandy was briefly downgraded overnight to a tropical storm, then was re-classified as a hurricane this morning when a reconnaissance airplane found hurricane-force winds. It continues to look ugly on satellite, and might be re-downgraded to a tropical storm later today. Again, none of this matters. This temporary weakening trend was and is expected. It doesn’t (yet) suggest that the models are wrong, or that Sandy will underperform its forecasts (as Irene and Isaac did). That might happen — there’s always the possibility that models are wrong — but we have NO EVIDENCE to suggest that yet. As Bryan Norcross wrote yesterday, “Either every model is wrong or this is serious as a heart attack.”

Please read Norcross’s whole excellent post from last night, and understand that — distracting noise about downgrades and “hybridization” aside — Sandy remains a deadly serious threat, including to hyper-vulnerable New York City.

Beyond that reminder, there isn’t too much new to report this morning. There continues to be some disagreement among meteorologists about precisely when, and how, this storm will fully transition from tropical to extratropical — but that’s a bit of a sideshow for the public, since Sandy will be a very serious storm regardless of whether it has a warm, cold, or hybrid core at landfall. As for its target, the European model still favors landfall in the Delaware Bay vicinity, while most other models are further north along the New Jersey coast, in a very dangerous position for a potentially catastrophic New York City storm surge. It’s too early to say who’s right. What’s clear is that some portion of the Megalopolis will take a very significant hit.

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Everyone from the Beltway north to New England needs to prepare — and do so TODAY. (Preparedness links can be found at the bottom of this post.) Don’t wait until tomorrow to prepare. Sandy’s forecast track is speeding up. Landfall is now expected to occur Monday night, not Tuesday, and bad weather will begin well in advance of the center. If you’re in the potential strike zone, PREPARE NOW.

By the way, you’ll note I mentioned New England. I would specifically include interior New England, not just the shoreline. You won’t hear a lot of talk about this in the media, but from an analysis by Dr. Ryan Maue (link is on a premium section of his WeatherBell site; free trial here) has me concerned about the possibility of higher-than-forecast winds and wind gusts north and east of the center. I’ll try to do a post later tonight explaining why that is so (though the meteorological mechanics of it, involving “tropopause folds” and “potential vorticity towers,” are a bit above my pay grade), but for now, suffice it to say, folks in New England — and throughout the area, for that matter — should make sure they secure any potential flying debris to the extent possible, and prepare for lengthy power outages, because I think interior wind may take a real toll there.

I am taking my older daughters to a football game in Laramie, Wyoming today (we live in Denver), so I won’t be in front of my computer for the rest of the day. I’ll have my iPhone and will undoubtedly update my Twitter account (@brendanloy) periodically, and I’ll try to post a quick update on this blog if major developments occur. But I would also highly recommend the following sources to stay abreast of developments:

(List after the jump.)

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[NOTE: For my latest updates on Hurricane Sandy, follow me on Twitter.]

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“It’s one of the ugliest looking hurricanes you’ll see,” writes Weather Channel Hurricane Specialist Bryan Norcross, “but Hurricane Hunters and satellite measurements confirm that it’s still tropical enough to be a hurricane… and it’s on track to cause a pile of trouble.”

Sandy is indeed still a hurricane, officially at least, as of 11:00 PM EST Friday. It’s “showing characteristics of a hybrid cyclone,” according to the NHC, and it will probably be temporarily downgraded sometime Saturday to a high-end tropical storm, as upper-level wind shear of 55-60 mph (!!) takes its toll. Again, though, this is not a sign of overhype, nor of Sandy underperforming its forecasts (as Isaac and Irene did). The computer models predicted this bout of weakening. They also predict that Sandy will eventually buck the shear, will move out over the unusually warm Gulf Stream waters, and will begin strengthening again, probably sometime Sunday.

Those models, by the way, also continue to spit out to predict scary forecasts like this and this. So this is no time to get complacent, folks. In fact, if you live in the potentially affected areas, Saturday is your day to really prepare, whatever that means in your specific circumstance. (Preparedness links can be found at the bottom of this post.) By Sunday, things will be getting frantic. BEAT THE RUSH, PREPARE NOW.

Anyway, back to the storm’s ragged appearance, which belies its deadly potential. Norcross explains what’s going on:

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.

As he put it in a tweet, “Either every model is wrong or this is serious as a heart attack.”

More, from the NHC’s 11pm discussion:

SANDY IS CURRENTLY EXPERIENCING ABOUT 50 KT OF VERTICAL WIND SHEAR WHICH IS DISRUPTING THE CONVECTIVE STRUCTURE. HOWEVER…VERY STRONG UPPER-LEVEL DIVERGENCE ASSOCIATED WITH A TROUGH SOUTHWEST OF THE HURRICANE IS LIKELY SUSTAINING THE CYCLONE. WHILE THESE CONDITIONS ARE FORECAST TO CONTINUE…IT IS LIKELY THAT SANDY WILL CONTINUE TO SLOWLY WEAKEN THROUGH 36 HR. SUBSEQUENTLY…THE DYNAMICAL MODELS FORECAST THAT INTERACTION WITH THE U. S. SHORTWAVE TROUGH WILL CAUSE SANDY TO RE-INTENSIFY PRIMARILY DUE TO BAROCLINIC ENERGY PROCESSES. THE INTENSITY FORECAST SHOWS SANDY REGAINING HURRICANE STRENGTH IN 48-72 HR. HOWEVER…THE CYCLONE WILL BE UNDERGOING EXTRATROPICAL TRANSITION AS THIS HAPPENS…AND WHEN THIS PROCESS WILL BE COMPLETE IS UNCERTAIN. REGARDLESS OF THE EXACT STRUCTURE AT LANDFALL…SANDY IS EXPECTED TO BE A LARGE AND POWERFUL CYCLONE WITH SIGNIFICANT IMPACTS EXTENDING WELL AWAY FROM THE LOCATION OF THE CENTER.

Again: we still aren’t sure exactly where Sandy will go, and a large section of the coastline will be affected regardless. Having said that, Norcross has some additional detail on the potential impact on one uniquely vulnerable city:

The ocean will rise along the coast as Sandy makes its 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 [i.e., NJ/NYC] 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.

Norcross has more to say about other regions, too. Read the whole thing.

As for New York, if you live in Zone A or B, I’d say it’s time to immediately prepare to Get the Hell Out in the event evacuation orders become necessary, as they well may. I’m not sure about Zone C. I haven’t been able to find out what surge level, in feet, each zone can withstand; they’re based instead on Saffir-Simpson categories, which is fairly useless with a unique storm like this. But we could be looking at a 6-10 foot storm surge in NYC, plus astronomical high tide — as opposed to the 3-5 foot surge in Irene — if Sandy slams New Jersey from the east. So, yeah… significant evacuations are going to be necessary, methinks, unless the forecast changes.

There’s a lot more to say, but I’ve gotta sleep, so I’ll leave it at that for now, and post more tomorrow. In the mean time, check this Twitter list for the latest information, including the new European model run when it comes out in the hour of 2-3am Eastern Time, and the new NHC advisory and forecast track at 5am Eastern.

P.S. Oh, I almost forgot… here’s the me on Omaha radio, on Smash Davis’s show this afternoon. And here I am on NYC radio, talking about possible election impacts.

I’ve leave you with a water-vapor satellite image of the storm:

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Good night. Sleep tight. Don’t let the tropopause folds bite.

A Word of Caution

October 26th, 2012 - 7:14 pm

[NOTE: For my latest updates on Hurricane Sandy, follow me on Twitter.]

Hurricane Sandy may be downgraded to a tropical storm tonight at either 8:00 PM or 11:00 PM Eastern. In fact, Sandy may technically already be a tropical storm; the National Hurricane Center’s 5pm discussion suggests that the data doesn’t strictly support its classification as a hurricane right now, but the NHC is waiting for additional reconnaissance data to confirm weakening before formally downgrading it. If such data comes in, the storm will likely be downgraded tonight. And yes, it looks terrible on satellite right now.

Do not be fooled by this. This was expected. Forecasters knew Sandy would struggle with wind shear today. The computer models foresaw that. Sandy’s struggles, thus far anyway, are not a bearish long-term sign for the storm’s future development. They are precisely what was expected.

For some time now, the forecast has called for Sandy to struggle with wind shear Friday/Saturday, then re-organize and intensify Sunday/Monday/Tuesday as it slips into a more favorable atmospheric environment — sort of a calm in between the nearby heavy-shear zones — and also moves over unseasonably warm Gulf Stream waters. At that point, the expectation is that it will begin to strengthen and deepen (i.e., its pressure will drop), possibly through a potent combination of tropical and baroclinic processes (though it appears likely to remain a warm-core system until landfall). Come Monday night and Tuesday, the models show Sandy “bombing out,” as a shortwave trough zips in to the south, wraps around’s Sandy warm core vortex, and explosively intensifies it. Somewhere around this time, something that I frankly don’t fully understand called a “tropopause fold” gets involved (maybe), and a reinvigorated, terrifyingly intense storm slams into the coast of the Megalopolis.

That’s what the models foresee. I freely admit there’s no guarantee it will play out that way — and indeed, it would be wonderful if the models are wrong, and Sandy doesn’t strengthen as much as they predict. That would be great news! But it’s not news that we can trumpet yet. There’s no sign yet of it happening. That’s the point: Sandy’s disorganization and weakening today DOES NOT suggest that the models are wrong about Sandy’s future strengthening, because what’s happening now is precisely what the models expected. So, as of this writing, we still don’t have any concrete reason to suspect that Sandy won’t become the disaster we fear.

I’m posting this as a forewarning against complacency — and because my head may explode if (when) people start saying, “See?! Sandy was overhyped!!!” when it’s downgraded tonight.

If I see any indication that Sandy is looking like it might be less-bad than feared, I promise I will tell you, as I have with previous storms like Isaac, Irene, etc. But as of yet, with this storm, I see no such indications.

[NOTE: For my latest updates on Hurricane Sandy, follow me on Twitter. You may also want to read my thoughts on potential election impacts from Hurricane Sandy. Additionally, I did radio interviews today for WCBS 880 AM in New York (listen here), KFAB 1110 AM in Omaha (listen here) and WBAL 1090 AM in Baltimore (no archive link yet).]

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Above: The impending clash of titans — a strong trough of low pressure (a.k.a. cold front) that would probably have produced a powerful Nor’easter even if no hurricane were present, and Hurricane Sandy, which is expected to join forces with the trough to create an epic storm of historic proportions.

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“The more data I see, the more I think we’re going to be talking about this storm for decades.”

That’s what meteorologist Nate Johnson said last night on the WeatherBrains live show about Hurricane Sandy. It’s a sentiment I keep seeing expressed again and again, in various forms, by pretty much everyone with pertinent meteorological knowledge. Not just serial alarmists, but everyone. (That includes plenty of AGW skeptics, for what it’s worth. This isn’t a global warming hypestorm. This is, potentially, a truly historic weather event, regardless of your stance on climate change.)

When you look at the data — at the best information presently available — you just can’t escape the conclusion that Sandy appears increasingly likely to be an unprecedented and extremely serious storm, as the Capital Weather Gang writes:

With computer models locked in on the eventuality of a punishing blow for East Coast from Hurricane Sandy (with the latest model runs favoring the northern mid-Atlantic), analyses suggest this storm may be unlike anything the region has ever experienced.

Model simulations have consistently simulated minimum pressures below 950 mb, which would be the lowest on record in many areas.

“Below 950 mb” is an understatement. Last night, a run of the HWRF model forecast an impossible-seeming 922-millibar storm at landfall (see below). That was Hurricane Andrew’s intensity when it hit Florida in 1992! The GFS and Euro models have also shown very low pressures in various models runs. Realistically, the models are probably overstating things a bit — Sandy probably won’t get quite that intense (and even if it did, its winds wouldn’t be anywhere near Andrew-like levels, because it will have a much, much wider and more diffuse circulation — in other words, gale- and hurricane-force winds over a huge area, but no central area of Category 3, 4 or 5 type winds) — but when the models are ranging from the 920s and 930s to more “reasonable” values in the 940s and 950s, you can’t help but take the storm seriously. The “perfect storm” was only 972mb! Anything below 960mb is pretty epic and historic.

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It isn’t just the barometric pressure that has folks alarmed, of course. So many of the potential tracks would bring devastating coastal flooding. The official NHC track could be calamitous for Delaware Bay. The latest GFS model could bring devastating flooding to the shores of Long Island Sound. And of course there is the New York Harbor nightmare. Or, Washington, D.C., the Delmarva and Chesapeake Bay could be crushed. Or the New Jersey shore could. It’s important to emphasize that we don’t know exactly where Sandy will go, and won’t for a while yet. But at this point, it’s hard to find a reasonably likely track that wouldn’t be a serious disaster for someone, in a region that’s so heavily populated.

Moreover, because Sandy is so huge, its impact will be widespread and long-lasting. North and east of the landfall point, its relentless onshore winds will pile up a storm surge over a wide area through multiple tide cycles — making each successive high tide higher than the previous one. With astronomical high tide on Monday, this is a particularly big problem. AccuWeather meteorologist Mike Smith (an AGW skeptic and non-alarmist) writes on his blog: “Based on some media coverage I’m seeing, the threat of flooding in coastal areas is being underplayed. Especially, if you live ten feet or lower above sea level, you need to be prepared to evacuate should the order be given.” I completely agree with that statement.

While we’re on the topic of ocean flooding, models suggest Sandy will stir up the ocean to an almost unbelievable extent, with offshore waves that are, well, just huge:

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And then there’s the potential rainfall… and snowfall!

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(The total rainfall would actually be greater than the graphic at left shows, because that’s only a 5-day forecast, going through Wednesday morning, when the storm is forecast to be inland over Pennsylvania, still dumping lots of rain.)

I’m picking up some skepticism of all this “hype” from commenters and on Twitter, by folks who say this is “just” a Category 1 hurricane or “just” a big Nor’easter, and the media is jumping the gun again, like they did with Irene and various other storms. (Actually, Irene arguably lived up to much of the hype, but I’ll leave that argument for another day.) This sort of critique, which is often more rote media criticism than actual storm-specific analysis, routinely fails to recognize that weather forecasting is an inherently uncertain probabilistic enterprise — meaning most worst-case scenarios, warned of days in advance, don’t happen; if we wait to discuss them until they’re likely or certain to happen, it’s too late to prepare — so you have to judge the validity of “hype” contemporaneously, not with the benefit of hindsight. And, given that fact, the “overhype” critique is particularly misguided and wrong-headed in the present situation. The currently available data suggests, almost unanimously, that the universe of realistic scenarios for Sandy ranges from “bad” to “very, very bad.” The moment that data shifts, and starts suggesting a lower probability of disaster, I’ll let you know, just as I did with Irene and Isaac when the data shifted toward more favorable outcomes in those cases. But right now, that’s just not what the data says.

Some folks — local TV news departments probably being among the worst offenders — will always hype every semi-serious storm, and even more folks (including national cable news writ large) routinely fail to walk back previously-justified hype when the data changes, or events on the ground prove the data wrong. But those of us who take our roles seriously only hype those storms that deserve it, and tamp down the hype when conditions change such that the storm no longer deserves it. Right now, this storm deserves it.

It’s also critically important to remember yesterday’s quote from meteorologist Brad Panovich: “Don’t let the Category of the storm or whether it’s ‘just’ a Nor’easter dictate your response. Your personal memories of previous storms are no use in this unique situation.”

Why, you may ask, is it so unique? Why is all of this happening? Why is a Category 1 hurricane so potentially devastating? The Capital Weather Gang gives the most succinct answer I’ve seen:

[T]he clash of the cold blast from the continental U.S. and the massive surge of warm, moist air from Hurricane Sandy will cause the storm to explode and the pressure to crash.

This is highly unusual for a variety of reasons, about which, more after the jump.

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[NOTE: For my latest updates on Sandy, follow me on Twitter.]
 
 
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Above: the latest GFS model forecast for Tuesday morning, hot off the presses (or rather the Twitters). That track and intensity — a Category 4-like 940 mb, albeit in a spread-out hybrid storm such that the winds would not be Cat. 4 level (and the model may be overdoing the intensity a bit anyway) — would be bad, bad, bad news for New York City and environs, if it were to occur. But remember, this is just one model run, the forecast is very uncertain, the computer models are still shifting around a lot, and Hurricane Sandy is, in any event, huge and growing — so it will impact a very wide area. Everyone from North Carolina to Maine is potentially at risk, and needs to watch this closely.

The Washington Post‘s Capital Weather Gang has another excellent roundup of information about Sandy. Perhaps the most important takeaway is this quote from Charlotte meteorologist Brad Panovich:

It’s very rare to see a strong tropical system merge with such a strong winter-like trough of low pressure. Throw in a full moon and the potential is there for a significant storm. This system is 1 part Hurricane, 1 part Nor’easter and 1 part Blizzard potentially. Impacts of all 3 types of storms are possible depending on location.

For those on the coast don’t let the Category of the storm or whether it’s “just” a Nor’easter dictate your response. Your personal memories of previous storms are no use in this unique situation.

One of the biggest mistakes people make when a storm threatens is to assume “I’ll be fine because I was fine in [prior storm X].” If this storm has you in its sights, don’t make that mistake. Prepare in the manner that’s prudent based on the forecasts and warnings for this storm, not some earlier storm. Every storm is unique — and this one has uniquely damaging potential. It could be worse than the so-called “Perfect Storm,” writes Will Komaromi, a University of Miami researcher:

The odds of a potentially historic meteorological event occurring in the vicinity of the northeastern United States next week are increasing. The players on the field are as follows: Hurricane Sandy traveling northward along the east coast of the U.S., a warmer-than-average Gulf Stream, a very deep upper-level trough over the central U.S. currently bringing snow to Colorado, and unusually strong high-latitude blocking … An increasing number of model forecasts are now “phasing” Sandy with the mid-latitude trough, and given the amount of upper-level jet energy available in this setup, this could become a particularly powerful phasing event.

Something similar happened in late October through early November 1991. It was known as “the Perfect Storm”, resulting in 13 fatalities and causing > $200 million in damages to the northeastern U.S. and fishing and shipping interests. In the Perfect Storm, northward-moving Hurricane Grace phased with a mid-latitude trough, similar to the one over the Central U.S. today. Normally a hurricane weakens as it moves northward, as it encounters an increasingly unfavorable environment. This means greater wind shear, drier air, and lower sea surface temperatures. However, with phasing events, the tropical system merges with the mid-latitude system in such a way that baroclinic instability (arising from sharp air temperature/density gradients) and extremely divergent air at the upper-levels more than compensates for a decreasingly favorable environment for tropical systems. The Perfect Storm deepened to 972 mb, and was at its strongest while out over the open ocean (but still whipping the coast with strong winds and heavy surf). …

Most of the models now indicate even stronger jet dynamics will occur next week than occurred during for the Perfect Storm, and that today’s storm could potentially deepen to well below 960 mb or even below 950 mb. The fact that the Gulf Stream is anomalously warm for this time of year means that Sandy will weaken less as a tropical system than it otherwise would have prior to the phase. Also, a very strong blocking scenario (very negative NAO) has developed over the north Atlantic means that the cyclone will be very slow moving, and is likely to retrograde westward into the northeastern U.S. rather than continue out to sea like most recurving extratropical cyclones do. While it is too early to pin-down exact impacts from the system at this time, it is likely that portions of the coastal Northeast will experience a damaging storm surge, significant beach erosion, and a prolonged severe wind and heavy rain event. Meanwhile, interior regions of western Pennsylvania into Ohio may simultaneously be experiencing heavy snowfall. Stay tuned!

By the way, about that “very deep upper-level trough over the central U.S. currently bringing snow to Colorado” … it so happens I live in Colorado, and here’s what it looked like this morning, along the route from my house to my middle daughter’s preschool:

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Apologies for the Obama sign, fair PJM readers. :) There aren’t very many Romney signs in this deep-blue city. Another shot, with no political signs, after the jump…

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Hurricane Sandy’s development was impeded a bit by Cuba — it likely would be a Category 3+ right now, if a mountainous land mass had not intervened — but it remains a powerful Category 2 hurricane, with 105 mph winds and a barometric pressure of 963 mb, as it moves into the Bahamas. And the National Hurricane Center’s 11:00 AM forecast has shifted west, following the consensus of the computer models, to squarely target the U.S. East Coast:

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You should not focus on the exact forecast track, particularly in the latter parts of the forecast, as the details are still very uncertain at this point. Everyone in the “cone of uncertainty,” from North Carolina to New England, should begin preparing for the possibility of hurricane-like conditions late this weekend or early next week. Also — another reason to focus on the cone, not the exact track — Sandy will have a very large wind field, with bad weather quite far away from the center. So a large area is going to be impacted by this storm.

[NOTE: For my latest updates on Sandy, follow me on Twitter.]

Widespread, long-lasting power outages are almost a given with a storm like this. Wind damage will be significant, particularly with leaves still on the trees (as opposed to winter Nor’easters), and particularly with heavy wind over such a wide area, which means affected areas will take a prolonged battering. Severe coastal flooding is also a serious threat, primarily north and east of wherever the storm’s center makes landfall. (Monday is astronomical high tide, making things worse.) Severe inland flooding from heavy rainfall is another big potential problem. Places where those two phenomena can happen simultaneously — for instance, the mouth of the Delaware River, where it flows into Delaware Bay — are especially at risk, if the center comes in just to their south. Which, as it happens, is exactly what the 00z run of the European model predicts for Delaware Bay:

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Yikes. I don’t want people to #PANIC about a specific model or a particular model run; any individual scenario is unlikely at this point, because there is still a lot of time and a lot of uncertainty. However, that particular scenario — what Joe Bastardi calls the “Philadelphia Story” scenario — is one of many that’s “in play” at the moment, which is distressing. Likewise, a New York harbor nightmare is another scenario that’s in play.

Aside from all the “usual” impacts of a hurricane transitioning into an uncommonly severe hybrid coastal storm and impacting the Megalopolis, this storm is going to hit one week before a presidential election, which raises a whole host of additional concerns. I discussed some of these yesterday, including the possibility that the occurrence of a national emergency could alter the dynamic of the campaign in its final weeks. But right now, I want to focus on the procedural issues, the impacts on the actual conduct of the election itself. For instance:

• Additional chaos and “irregularities” on Election Day due to lost “prep” time. I spoke this morning with my father, a retired elections bureaucrat in Connecticut, and he made the excellent point that the week before the election is very busy for folks like him in his old job, and for registrars of voters, town clerks and the like. They’re testing voting machines, printing ballots or other critical papers, and doing all sorts of other mundane tasks that are critical to assuring a smooth Election Day. If the impact of the storm wipes out all or part of that critical “prep week,” then even if things are relatively “back to normal” by Election Day (by no means a given; see below), there would likely be an invisible storm impact in the form of additional chaos, “irregularities” and all manner of disruptions at the polls — failed voting machines, missing ballots, etc. — simply because the officials had to cut short their preparation, so more mistakes will inevitably happen. This, in turn, will increase the already-high likelihood of cries of fraud (from Republicans) and suppression/disenfranchisement (from Democrats) in the event of any remotely close outcome. Basically, Sandy is likely to make an already highly charged atmosphere surrounding the conduct of the election even moreso.

• Lower turnout impacting various elections, and possibly giving Mitt Romney the national popular vote. If power remains out, some roads remain impassable, and people’s lives are generally disrupted in a myriad of ways a week after the storm in heavily affected regions (all of which seems entirely plausible), it is likely that lower turnout would result. This is especially true in states where the presidential race is not hotly contested — basically, the entire region except for New Hampshire, Pennsylvania, Virginia, and Ohio — so voters may be less-motivated to vote, and the campaigns would certainly be less-motivated to pull out all the stops to help them do so amid difficult circumstances. If turnout is particularly affected in Democratic strongholds like New York, much of New England, Maryland, etc., it could depress President Obama’s national popular vote numbers, and help make an already much-discussed scenario even more likely: Obama wins the electoral vote and thus the presidency, but Romney wins the national popular vote (essentially, a reverse of the Gore/Bush result in 2000).

Of course, lower turnout in Virginia, Pennsylvania, New Hampshire, and/or — above all — Ohio, would be far more significant, as it could impact the Electoral College outcome. The nature of such an impact is a little hard to gauge, though. Obviously, it depends on which regions within those states are hardest hit. For instance, if Philadelphia is ravaged by Sandy, it could be an enormous problem for Obama, turning a state that appears to favor him into a real tossup, and perhaps a national tipping-point state. Conversely, if western Pennsylvania is hit especially hard — whether by copious rain and strong winds, or possibly by heavy snow (!) — it could hurt Romney, and put the Keystone State far out of his reach. Similar analyses would hold in other states where the voting patterns are very regional.

More broadly, due to the “enthusiasm gap,” among other factors, low turnout probably favors the Republicans, at least in states without early voting. In states with widespread early voting (like Ohio), low Election Day turnout probably favors whichever party is doing better in early voting. I have no idea what the impact would be on key Senate races in places like Connecticut, Massachusetts and Virginia (and to a lesser extent the marginally close races in Pennsylvania, Ohio and Maine); it presumably would depend in part on the local “enthusiasm gap” there vis a vis the Senate races, but I don’t know what those numbers look like.

• Widespread power outages causing disruptions in voting. This one seems highly likely to occur, in some form or another, in various places. Think back to Hurricane Isaac, or the summer derecho, or last year’s Halloween snowstorm. Widespread power failures don’t just get fixed overnight. A week after the storm, significant portions of the hardest-hit areas will likely still be without power. What will this mean?

Well, the first question to ask is, what kind of voting machines do the potentially affected areas use? VerifiedVoting.org has a helpful map showing the types of systems in use, state-by-state — and county-by-county, if you click on an individual state (for instance, Pennsylvania, Virginia and Ohio). You can even click on the county and find out the specific manufacturer of the machine they use there.

As it happens, all of New England and New York apparently uses “optical scan” paper ballots, which means the process of voting can theoretically take place without electrical power (although it may be difficult to see the ballot without lights!). Typically, as I understand it, voters submit their ballots by feeding them into the optical scan machine, which may or may not have enough battery power to continue working in such an environment (I don’t know that answer, and suspect it varies from manufacturer to manufacturer). But, worst-case scenario, presumably the ballots can be placed in a box, then submitted to the optical scan machine later, once power is back on. This could severely delay the counting of ballots (more on that later), but would not prevent people from voting.

More potentially problematic are the “DRE” (direct-electronic recording) machines, usually called “touch-screens.” Those are used throughout all of New Jersey, Maryland and Delaware, and most of Pennsylvania, Virginia, West Virginia and Ohio. For instance, Pennsylvania’s Philadelphia and Delaware counties — which would be very hard-hit in the Bastardi/EURO scenario — both use Danaher Controls’ Shouptronic 1242 model. Good news there: according to a report (PDF) by the Department of Elections for New Castle County, Delaware, the Shouptronic 1242 is supposed to keep functioning even when the lights are off:

In the event of a power outage the Electronic 1242 is equipped with a battery backup adequate to maintain normal operation for up to 16 hours. The internal power supply maintains the battery charge when power line voltage is normal to assure that the backup battery is fully charged and immediately ready for use if the AC power fails.

Assuming the battery is fully charged before the power goes out, and assuming the machine remains off until Election Day, that would seem to be good enough to keep things going. But I have no idea (and don’t have to check) whether every DRE system is equally robust, or if those 16-hour assurances have been fully tested, etc. And in the event of widespread machine failure, don’t just assume “oh well, people will just use paper ballots instead.” It’s not that simple. Election officials do not routinely print enough paper/provisional ballots for the entire electorate to use them. If the regular voting machines don’t work, there will be mass chaos at the polls — and probably a great deal of disenfranchisement — unless these places have a very good contingency plan, and put it into place well in advance.

Moreover, my point about polling places lacking electricity and lighting is not a trivial concern, even if the machines themselves are workable. The many thousands of polling places in school gymnasiums, local libraries and whatnot aren’t typically hardened against power outages, and likely lack a contingency plan for bringing in generators and such on short notice. It is easy to imagine last-minute changes in polling place locations, many voters trying to vote in the “wrong” precinct because theirs lacks power, etc. At a minimum, I would anticipate a whole lot of chaos, confusion, and a higher-than-usual number of provisional ballots being cast.

• Widespread power outages causing major delays in vote-counting. Casting ballots is one thing; counting them is another; and communicating those vote counts to a central location is yet another. We are used to rapid vote counts filling our screens on Election Night, telling us who the winner is (albeit based on unofficial returns) within a matter of hours, except when the result is razor-close like in 2000. However, such speedy counting depends on thousands of local polling places having the ability to tally and transmit their vote totals shortly after the polls close. Without diving too far into the weeds again, it’s easy to imagine widespread power outages causing all sorts of disruptions to this process. Consequently, we could easily see a number of states with uncommonly slow vote counts. If the slow-counting state is, say, Vermont or Maryland, nobody will much care nationally; if it’s, say, New Hampshire or Virginia, it could make for a frustrating night.

More after the jump.

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Whither Sandy?

October 25th, 2012 - 10:23 am

Almost all of the computer models now agree that Hurricane Sandy — which unexpectedly ramped up to a Category 2 last night, and doesn’t seem to have weakened much over Cuba — will hit land somewhere along the U.S. East Coast or the Canadian Maritimes. But there is still huge uncertainty as to where.

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More later.

Hurricane Sandy’s barometric pressure dropped a whopping 32 millibars in 21 hours Wednesday, reaching as low as 954 mb and increasing the winds to 110 mph — high-end Category 2 — by landfall in Cuba. Here’s what the storm looked like just before landfall, and what it looks like now:

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There’s a lot to say about Sandy’s future, but unfortunately, I literally fell asleep on my couch while trying to compose a blog update on it! So stay tuned — more tomorrow (er, later today). But for starters, go read what fellow weatherblogger (and author) Mike Smith, from whom I took and quoted the “Big Potential; Big Uncertainty” language, had to say on his blog. See also Dr. Jeff Masters and Dr. Bryan Norcross.

Again, more later.