How does a nor'easter form and what kind of conditions characterize this type of storm? Geoff Cornish finds out in this episode of Ask The Experts.
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00:00Welcome to AccuWeather's Ask the Experts. I'm Jeff Cornish. We go beyond the forecast
00:16to give you the how and why on all the cool and interesting things you've wondered about
00:20and wanted to ask in weather, space and science. And today we're going to talk about winter
00:25weather, specifically nor'easters, how they are formed, we'll dive into their impact across
00:31some big populated cities across the Northeast, and not just during the winter months and
00:36other parts of the year, they impact areas as well. So joining us today to break all
00:40this down is AccuWeather's Senior Vice President Evan Myers. Evan, thanks for making time
00:43for us. Oh, absolutely. Pleasure. It's always good talking to you. You're a wealth of historical
00:48information tied to the weather and meteorology itself as well. It's making me feel old. You
00:54have a knack for weather history and its impact, especially in the Northeast. So we
00:57want to talk about nor'easters in general and break down what they are. We throw the
01:02term around a lot, but how would you define a nor'easter? How do they form? Well, a nor'easter
01:07is just a very powerful storm that, I shouldn't say just, is a powerful storm that forms generally
01:13in the wintertime, but it's not confined to the winter, and it generally has very strong
01:19winds, heavy precipitation with it. It doesn't necessarily have to move quickly. Some nor'easters
01:26have sat and spun off the east coast of the United States for quite a while, and it really
01:33gets its terminology from the direction that the wind's blowing. Not the direction the
01:38storm's moving in, but the fact that along the eastern seaboard where nor'easters are
01:44mostly felt, the wind is out of the northeast, and it was kind of shortened to nor'easter.
01:50First used, I think they coined the expression in the mid-1830s was the first time that phrase
01:57was used by a newspaper, I think it was in Boston, about a storm that was impacting New
02:02England with heavy snow and powerful winds. So what kinds of conditions are on the table,
02:09at least from a weather standpoint here, before storms like nor'easters do form? So it's interesting.
02:14I'll throw out a term here, thermodynamics. So before we get too technical with people,
02:21what does thermodynamics mean? It's thermal, it's temperature, and the dynamics around
02:28the change in temperature. So it's the same type of thing that exists or influences the
02:33formation of hurricanes, it's just in a different manner. Hurricanes, and people have often
02:39compared nor'easters to hurricanes. So for a hurricane to form, you have to have a tremendous
02:46release of heat, and that latent heat is released when thunderstorms form and a lot of heat
02:53is released, it's like the heat that's released when you have a hot cup of coffee. It cools
02:57off because the heat is being dispersed, diffused into the atmosphere. So that's how hurricanes
03:04form, because they're warm core. How do nor'easters form? It's the same type of thing except it's
03:10in the reverse. It's pockets of extremely cold air, so there's a tremendous contrast
03:16in temperature between the surface and higher up in the atmosphere, much more than you get
03:20in the summertime. And so the greater the contrast, the stronger that storm is. So that's
03:26one part of it. So that's the thermodynamics, or the actual change in temperature is really
03:31all that means. Also, it has to do with the flow in the upper atmosphere, what kind of
03:37strong winds you might have, and how those winds spin in a counter-clockwise manner just
03:43like storms operate in counter-clockwise manners. If the spin in the atmosphere, and I'll get
03:50technical again, the vorticity that's created by that, and that's not also, it sounds technical,
03:58but it really isn't, because it's a vorticity. Anybody that's filled up their bathtub and
04:03then pulled the plug, you get the spin. It's the same idea with actual any storms, hurricanes,
04:09and also nor'easters, you start to get that spin. But if that spin occurs and increases
04:15in the upper atmosphere, you have the twisting, you have cold air aloft, big difference in
04:20temperature, and those are the factors that really cause big, strong winter storms, nor'easters,
04:27to form along the eastern seaboard or to move across places like the Midwest and actually
04:32explode off the eastern coast.
04:33And if you go one or two hundred miles out there, the Gulf Stream, even in the middle
04:37of winter, is relatively mild. It's not always about the temperature, it's about the contrast
04:41in temperature that drives the bus there.
04:43Well, it absolutely is, and so you have an even greater contrast in temperature and that
04:47helps fuel it, and some people speculate that it also helps fuel the moisture that's available
04:52to these storms as well to kind of throw them, throw that moisture back onto land and cause
04:58a tremendous, prodigious, biblical type of snowfall accumulation.
05:04And we've had some great storms in history. We can go back to the 1800s and 1900s. When
05:08I was 12, we had the Superstorm of 1993, spectacular nor'easter across the seas.
05:13I won't say how old I was then.
05:15That's fine. But what do you remember most about the Superstorm of 1993?
05:19Well, in 1993, we had winds up to 100 miles an hour. We had snowfalls up to 50 inches.
05:27Some of the big cities, especially in New England and down toward New York City, had
05:31a foot, two feet of snow. And so the combination of the wind and the snow falling just caused
05:39impossible drifts to clean. It just took so long for that to happen, for the cleanup to
05:45occur. That's kind of what I remember.
05:47I also remember my oldest son. I remember him looking out the window and seeing the
05:52snowstorm and telling him that's something he would probably remember for the rest of
05:56his life. And he still does remember that.
05:58I believe it. That's great. And then behind this, tremendous cold down into Birmingham
06:02and other areas across the South.
06:04Well, those cities actually, I think Birmingham had a foot of snow. The cold on the backside
06:09of the storm was amazing. Florida, I think Tallahassee had several inches of snow. So
06:17big snowfalls in the South, and inches of big snowfall. But many inches of snow that
06:23far south, unprecedented historically, as long as people were keeping records. Who knows
06:29back hundreds of years ago, but at least back over the last century or two, nothing ever
06:35occurred like that.
06:36And we do a lot here at AccuWeather with our data analytics team looking at economic impacts.
06:41And if you have more people in the line of fire for any given storm, certainly a higher
06:44impact. Nor'easters get a lot of attention because of the part of the country that they
06:48impact. So what are some big cities that see the greatest impacts for nor'easters?
06:52Well, generally nor'easters have the biggest impact from Washington, D.C. on northward
06:56up to Boston and to New England. So D.C. and Baltimore and Philadelphia and New York, there's
07:02a lot up to Boston. There's a lot of people that live there. And most of the infrastructure
07:06is right close to the coast or inland, not even 100 miles. And so they're really impacted
07:12by the heavy snow. And if enough warm air comes in from off the ocean, which often
07:17can occur when the storm really wraps up, you get all kinds of heavy rain. You get flooding.
07:21So what it really does is cause economics to grind to a halt for a while because you
07:26can't move goods. People can't travel. It shuts down airlines. And over the last decade
07:33or two, a lot of airlines have taken their planes out of harm's way. So they don't just
07:40shut down when the storm's going on, those flights. They're shut down days in advance
07:44because they move those planes away so they can bring them back a little bit faster. But
07:49still, it has a tremendous impact, mostly on travel, but on a lot of other things. You
07:55know, it's funny. For years, I did a lot of radio broadcasts for AccuWeather in some of
08:00the big cities in New York and Philadelphia and Boston. And people on the air would ask
08:06me on the other side, the news folks, like, should the kids do their homework for tomorrow?
08:12So the thing I always said was, you know, it doesn't matter if they're school or not,
08:17you should always do your homework.
08:18There you go. I grew up listening to KYW 1060, another client that we have here at AccuWeather
08:23right now. And we had that for many years when I was a kid. We'd be listening to you
08:26and you'd be listening to me.
08:27And you'd listen to me, probably.
08:28I'd listen to you and Elliot and many, Dave Dombeck, absolutely.
08:31But I always said that, so.
08:32Bob Larson.
08:33Yeah, good stuff.
08:34Exactly, yes.
08:35Now I get to work with him. Well, March of 2018 produced four Nor'easters in one month
08:41in the Boston metro.
08:42Yes.
08:43Four Easter. This is pretty incredible. So how rare is an event like this to get four
08:47over four weeks?
08:48Well, it's not really as rare as you might think, because once you get into a weather
08:53regime, a pattern that gets established that doesn't break, and oftentimes what caused
08:59something like that is you get a very strong flow out of the Northwest that comes out of
09:03central Canada, but you're still, kind of the jet stream gets split in half. You have
09:08very strong winds coming out of Canada, cold air, but you also have a somewhat weaker jet
09:14stream that's coming up out of the South, and so you get moisture. And what happens
09:18is as the jet stream moves into New England or moves into the Midwest, it starts spinning
09:24up into that vorticity that I talked about.
09:27But if the overall weather pattern itself, the overall jet stream doesn't move out
09:31of that regime that it's in into that pattern, so you get one storm that spins up, moves
09:37away, it calms down a little bit, but then the next one moves right into there. I remember
09:43here in State College where AccuWeather's headquartered, we had three storms like that
09:48in a week because of this. It wasn't over four weeks, it was in one week.
09:52Pretty spectacular.
09:53It was. It was sometime, I think, in the 80s, and what we had was as the snow ended from
09:59one storm and it cleared out in the evening, by the next morning, the clouds were already
10:04moving in from the next storm, and it happened three times in a row.
10:06Not long before we recorded this, there was a scenario where Denver had three snows in
10:11one week. We had persistent dryness in the east, persistent trough in the west. The atmosphere
10:15needs something to dislodge those long wave patterns sometimes, and sometimes they don't
10:19come until the big storm rolls in.
10:20Well, that's right, and sometimes that's enough to disrupt the weather pattern. And then,
10:24of course, and when we get, not of course, but as we get later into the winter, oftentimes
10:29we'll get storms that actually become cut off from the rest of the upper atmospheric
10:34flow, and those storms just kind of meander around, and some of them, like the 1962 storm
10:39that sat off the New Jersey coast for about three to five days, caused tremendous beach
10:46erosion, all kinds of flooding problems because it didn't move.
10:52Coming up next, Nor'easters don't only happen during winter, plus we'll answer more of your
10:55viewer questions when Ask the Experts returns.
10:59Welcome back to AccuWeather's Ask the Experts. I'm Jeff Cornish, and today we are talking
11:08all about Nor'easters, and joining us again to break some of this down, some impactful
11:13storms from history, is AccuWeather Senior Vice President Evan Myers. Thanks again for
11:17being with us here.
11:18Absolutely.
11:19Well, we love talking to you about, especially, northeast weather. You've lived it, and you've
11:22been here for, well, you spent your career here at AccuWeather.
11:25I have, yes. See, I'm glad you didn't say how many years it was. That's okay.
11:28Undisclosed number of years. Nor'easters are not just confined to the winter months.
11:34No, they're not.
11:35They're used in the bumper seasons as well. There have been a couple of very memorable
11:38storms, especially in the fall, sometimes even around major holidays, like Thanksgiving
11:43or Halloween. So, Halloween of 1991 was a big one. Could you talk about that event?
11:49Well, I lost a tree in my backyard. I remember that, and that's one thing that I think makes
11:54storms in the early part of the season, or in the late fall, even more memorable, because
11:59trees still have their leaves on them. Bushes still have the leaves that can cause basically
12:06destruction of your shrubbery, or trees to come down. And I lost a tree because half
12:11the tree limbs fell off. I also remember going out with a broom and hitting some big bushes
12:17I had to get the heavy work snow up, because in that time of the year, because the atmosphere
12:22is still pretty warm, the surface temperatures are pretty warm right around freezing, you
12:26get those giant snowflakes coming down that are heavy, and they're sticking onto every
12:33tree limb, all the wires. So, that's when you get a lot of things that come crashing
12:38down to the ground, the tree limbs and the wires. A lot more power outages that time
12:43of the year, especially in the northeast from nor'easters. When it's colder, the snow tends
12:49to just powder off of those things, but in the fall, it can be a real mess. You compound
12:57it by the leaves on the ground, makes it even slipperier. It's a real mess, and I think
13:01that's why folks think about it so much. As you get deeper and deeper into the season,
13:07you become used to it. You become a little bit numb to heavier snow, but not in the beginning
13:10of the year, at least in places that get a lot of snow.
13:13Right. Now, I agree. Sometimes you get those spectacular photos of the fall foliage and
13:17the snow, but it comes with a price tag. Those deciduous leaves catch all those heavy
13:21wet snowflakes, and it's a mess.
13:24It's interesting. When you watch a movie and they're faking the snow, look for the shrubbery.
13:32Because in the beginning of the year, the beginning of the winter season or the end
13:37of the fall, those leaves are starting to turn. But if everything's all green and you
13:41see snowflakes coming down, that's not right.
13:44Right. It's not happening in August.
13:46We also had, just briefly, another Halloween event in 2011 that was also a major northeast
13:52impact. That was a deadly storm. In fact, we even have some graphics there that shows
13:55that we had over a foot of snow in parts of the Poconos, the Catskills. Not every deciduous
14:00leaf was on the ground at that point, so that's a big problem.
14:02That's to say you're going to technical terms like thermodynamics and deciduous leaves,
14:07so there you go.
14:08There you go. We do have another question for you regarding a viewer question. This
14:13one comes from Diana in Pennsylvania. Diana writes, what is thundersnow and why does it
14:18happen?
14:19Well, it happens because we talked about that temperature contrast. The greater the temperature
14:24contrast, the stronger the storm. Really, in the summertime, a big temperature contrast
14:34will often cause really violent thunderstorms. You can get thunderstorms in the middle of
14:40these big snowstorms in these nor'easters because they're so cold in the upper atmosphere,
14:46and yet the contrast is much greater. Even if it's cold at the surface, we're talking
14:51about temperatures way below zero.
14:53It's about the contrast.
14:54The contrast is much greater, so it's the same thermodynamics, the same dynamics, the
14:59same change of temperature causes that. It's funny, I recall way back when we first started
15:05with KYW Radio in Philadelphia, when Elliott Abrams was doing the broadcast, and he called
15:12up and he said, we need to put thunder and lightning into the forecast. The person he
15:18was talking to at the other end said, it's the wintertime. We don't get thunder and lightning,
15:24and then all of a sudden in the background you hear this boom of thunder, and the guy
15:29on the other end goes, anything you say, Mr. Abrams.
15:33It's interesting how society has changed because now with cell phone video, all types of weather
15:39are more accessible, and I think people are more aware. So I don't think, even if there
15:43was no change in the frequency of thundersnows, people probably wouldn't ask that same question
15:47now because they've seen videos of it.
15:49But it's still pretty rare, and when that happens, when you think about it, you have
15:53the snow falling, it's all white, it's all bright, and then all of a sudden you see some
15:59lightning, even though you can't see it, and you hear it, it's pretty mind-numbing when
16:05you think about all the different things the atmosphere can throw at you at the same time.
16:10And I think that's part of it, it is, yes.
16:12It's what keeps us coming back for more.
16:13Well, at least the two of us, anyway.
16:15That's true. And we included that in our Nor'easter show because Nor'easter is a great way to
16:20produce thundersnow, more than most other snow events.
16:23Absolutely, because of the tremendous intensity that occurs, and we hear this term bomb cyclone
16:30and that refers to the tremendous development, almost the explosive development that occurs
16:36in Nor'easter, so that's where the bomb comes from, it's like an explosion because it happens
16:40so quickly.
16:41And you touched on this earlier, you mentioned the storm that lurked off the Jersey Shore
16:45for four, five, six days in the past. One of the big impacts often catches up to us,
16:50at least in the Beachtown bank accounts as we approach the summer season, the beach erosion
16:56is a huge problem with this.
16:58It is. So all these storms do cause tremendous beach erosion, and the storm in particular
17:04you're talking about in 1962 in March off the New Jersey coast, it caused several naval
17:10ships to be beached, and it really cut some of those barrier islands that you think about
17:16north of Atlantic City, south of Asbury Park, in many pieces.
17:20Yeah.
17:21And the Army Corps of Engineers actually came in and repaired them over the course of several
17:25years, but a lot of those communities were almost totally wiped out in 1962 by this March
17:32storm because it's a snow hurricane in effect.
17:35Right, yeah, this is a Nor'easter, not a named hurricane or anything like that. Well, we
17:39are short on time, so AccuWeather Senior Vice President Evan Myers, thanks again so much
17:43for your insight.
17:44Absolutely, my pleasure, yes.
17:45We love talking to you about this stuff here. And coming up next in WeatherWise, we're going
17:48to bring you three interesting things you may not know about snow. Find out where it's
17:53never snowed in the U.S. when Ask the Experts returns.
18:05It is now time for WeatherWise, and today we're bringing you three interesting things
18:08about snow. First, which is the country with the most snowfall? This one might surprise
18:14you. The answer is Japan. So the Japanese Alps get between 300 and 500 inches of snow
18:20per year, while the northernmost part of Japan, up in Sapporo, they get about 600 inches.
18:27Although this ranks 62nd in terms of geographical size, Japan is known to receive the highest
18:33amount of snowfall in the world.
18:35Next here in the United States, which relatively large city gets the most snow? Looking at
18:40cities of around 100,000 population or more, Syracuse, New York, takes the crown on this
18:45one at more than 120 inches of snow a year. Syracuse has the highest annual average snowfall.
18:52Lake Effect snow from nearby Lake Ontario is a huge factor in driving the heavy snow
18:56that falls in the center of New York State. There are other smaller towns in eastern New
19:01York and upstate New York that get over 300 inches per year. And then Marquette, Michigan,
19:07averaged between 175 and 190 inches in a typical year. But that's a smaller city.
19:12Finally, where in the United States has it never snowed? And the answer is Key West,
19:16Florida. The vacation spot is the southernmost location in the continental U.S. With Key
19:21West's warm temperatures and tropical climate, snowfall is virtually impossible. They have
19:26water on all sides. There has never been any recorded snowfall in Key West. And not only
19:31has Key West never experienced snow, it's never seen frost, ice, or sleet either.
19:35Thanks so much for being with us here on AccuWeather's Ask the Experts. I'm Jeff Cornish. Don't forget,
19:40whenever you have a question about weather, space, or science, you can email us at asktheexperts
19:44at accuweather.com or call us at 888-566-6606. Have a great one.