A Strengthening La Nina means an easier winter?
La Nina, which is the opposite (cold) phase from El Nino (warm) phase in the tropical Pacific, is what we've got for this winter. I won't bury you with all the complex jargon as to what precisely El Ninos and La Ninas mean in detail, but I will tell you these distant phenomena have worldwide weather effects, including in our viewing area. A strong El Nino (such as in the late 90s) generally is a reliable signal from nature that we can expect a milder and drier winter than normal. In that late 90's event February, for example, brought only .25" of snow to the Buffalo airport, and people were jogging in their shorts in mid-winter. So shouldn't the opposite occur when we have a strengthening La Nina? Statistical research, much of it done by meteorologist Bob Hamilton at the Buffalo National Weather Service, shows that's not usually the case. His examination of past La Nina years shows little correlation with colder winters and moderate La Ninas in WNY. Weak to moderate La Ninas, in fact, have been associated with warmer than average winters here.
Right now, we have a moderate La Nina which is still strengthening. With that in mind, the National Weather Service's Climate Prediction Center projects decent odds for much of the lower 48 to have a milder than average winter, with no region likely to have a colder than average winter. In my own Preliminary Winter Outlook (wivb.com, Weather Page, lower left) however, I made note of another phenomenon which occurs over the North Atlantic, called the North Atlantic Oscillation. This oscillation, like that in the Pacific, has a Cold/Negative and Warm/Positive phase. When the NAO goes Cold/Negative it can overwhelm, for a few weeks at a time, the otherwise warm pattern over the NE and eastern Canada. Somewhere along the line this cold weather season, I would expect the NAO to go Cold/Negative at least twice. For those time periods, that would bring us much more wintry conditions. As of this posting, there are no clear signs of the NAO going Cold/Negative in the next 2 weeks. As soon as I see such a sign, I'll let you know ASAP.
Right now, we have a moderate La Nina which is still strengthening. With that in mind, the National Weather Service's Climate Prediction Center projects decent odds for much of the lower 48 to have a milder than average winter, with no region likely to have a colder than average winter. In my own Preliminary Winter Outlook (wivb.com, Weather Page, lower left) however, I made note of another phenomenon which occurs over the North Atlantic, called the North Atlantic Oscillation. This oscillation, like that in the Pacific, has a Cold/Negative and Warm/Positive phase. When the NAO goes Cold/Negative it can overwhelm, for a few weeks at a time, the otherwise warm pattern over the NE and eastern Canada. Somewhere along the line this cold weather season, I would expect the NAO to go Cold/Negative at least twice. For those time periods, that would bring us much more wintry conditions. As of this posting, there are no clear signs of the NAO going Cold/Negative in the next 2 weeks. As soon as I see such a sign, I'll let you know ASAP.
posted by Don Paul at
2:08 PM
25 Comments:
A moderate La Nina thats still strengthening? Does this mean winter lovers out there are in for a big disappointment this year? I can only hope that this NAO goes Cold/Negative enough to give us a real winter.
I'm totally new to this Blog thing, but why not give it a try. I attended a fall meeting for part of National Ski Patrol last year, about this date in Yosemite. There was a guest speaker there from the Nat. Weather Service office in San Bernadino, I think. He gave a similar explaination of El Nino and La Nina and his insights into the weather last winter was very accurate. It does seem like more gather of data is needed for verifying the predictable effects but it is interesting.
Butch of Onoville.
As far as the current La Nina in progress, there is a general consensus that this winter will be milder than average, even if occasional snowy and cold outbreaks are factored in. The conditions which give our viewing area the highest likelihood of a colder winter are those in which the pattern over the tropical Pacific is neutral. That is, neither El Nino or La Nina are in place. That allows the occasionally Cold/Negative NAO to have a greater impact on us, even when it's not a strong Cold/Negative NAO.
Right now, probabilities of La Nina fading and returning to a neutral pattern during this winter are quite low and, if that were to happen, it would be later in the winter. Last year, we had a weak to moderate El Nino in place after the October storm for most of November, December, and the first 2 weeks of January, producing unseasonable warmth. But that El Nino rapidly faded to a neutral phase during January, allowing colder and somewhat snowier weather to return for the 2nd half of winter with greater frequency.
Im really hoping for a white christmas and a white winter in general... do u think (or can you give an educated guess) as to whether or not this winter will be snowy and cold unlike last year... when on Christmas day i believe it was 45F! Im hoping that you are wrong about La Nina for this year... maybe it will have the "predictable" effect on our weather... cold and snowy!! What do you think?!?!
There is no "educated guess" for whether or not we'll have a White Christmas at this early juncture.
As I said, we may take a couple or a few wintry "shots" this winter, but as for an overall colder and snowier winter than average--there's no reason to believe that's what's going to happen. The available data says otherwise--a milder than average winter.
It seems like we havent got a old wny winter around here in a long time.
Yeah whats up with that. So when were in the warm part we will see above freezing temps right?
For those of you reading this La Nina/El Nino blog.... Simply put, "La Nina" is characterized by abnormal COOLING of the Pacific Ocean water. El Nino is just the opposite...abnormal WARMING of the Equatorial Pacific. Either one of these large scale events helps to change the global weather pattern. Again, these are large scale patterns. So, regardless of whether it be a strong or weak El Nino/La Nina, we must not forget about the synoptic and smaller scale events that have a much more dramatic impact on local weather....including the good ole lake effect machine!
If I remember correctly we had a La nina of similiar strength in 01-02. That was also the year we got plastered with 80 inches of snow over the christmas holiday. Let's pray to the Lake Effect "Gods" to save us again and pile on the snow!
Nick, you are correct! 2000-2001 was a La Nina winter. However, that incredible Christmas week snow was more closely related to a short term pattern change made more likely by a Cold/Negative NAO, as I've explained earlier.
Most of the rest of that winter was quite mild.
There are some hints that around Dec 3-5, we may see a more Negative NAO develop, while a strong ridge of warm high pressure develops over western North America. This would force the polar jetstream to go over the top of that ridge in NW Canada, and then dive to the SE over northern plains and Great Lakes. We'll see if this trend continues in later computer model runs over the next couple of days.
Is it possible to have a snowy winter during a La Nina year? I'm thinking in terms of the lake not freezing due to warmer temps, which could lead to the possibility of LES? I know there are other factors such as shear and air temperature at higher altitudes, but generally speaking, is this possible?
It is definitely possible to have a snowy winter during a La Nina year. When I discussed the overall outlook as being a milder than average winter, that doesn't preclude fairly abundant snow. In the majority of cases, milder winters have less snow, but there are some notable exceptions. You can also have a cold winter with less snow. We've had seasons in which the prevailing tendency was for a NW flow to develop in the wake of passing low pressure systems. Buffalo doesn't see much accumulation with NW winds crossing the lakes.
Seasonal outlooks have limited reliability to begin with, and precipitation trends verify with somewhat less skill than temperature trends, in most cases.
Man I really wsh we just had an old-fashioned winter with lots of snow and cold. I'm sure this is the question that would be asked eventually, but does this have anything to do with global warming? Every winter now seems to get warmer, kinda depressing. I've heard that global warming could result in the next ice age because of something to do with ocean currents, it was on The Day After Tomorrow, good movie overall. What's your say on this? I also have to say that this blog thing is really cool, it lets the people converse and relate to the meteorologists on the news, really neat. No one else does this, so keep it up! And make sure we get a snowy winter or else!
Personally, I have little doubt that global climate change has some connection with the overall moderating trend of our winter temperatures. But to quantify how much of that global influence has brought warming in winter would be very difficult.
As for the Ice Age-caused-by-Warming theory, I wouldn't rely on the junk science in the Day After Tomorrow. That was originally the brainchild of wacky radio host Art Bell, a fine broadcaster but, in my estimation, a huckster of the first order.
There is a germ of truth in his wild plot, however. The prestigious Woods Hole Oceanographic Institute has done extensive research on ice core and sediment samples in the North Atlantic region. They have found some still inconclusive evidence of amazing quick cooling periods in the earth's past which may be related to the Gulf Stream and North Atlantic salinity. Here's the hypothesis: The high salinity of the North Atlantic waters causes that water to sink and, in a giant ocean conveyor belt current, to flow along the sea floor toward equatorial regions where it finally warms and rises into the Gulf Stream current. That current is what keeps the NE part of North America and much of NW Europe as relatively warm as they are in the winter. If you look on a map, NYC is closer to Rome's latitude, and cities like London are much further north. If the Gulf Stream were to slow considerably or, worse, to stop, winters in NW Europe and NE North America would be far harsher.
The Woods Hole hypothesis points to a dilution of North Atlantic salinity cause by fresh water melting from glaciers and snowpack. Should this dilution continue to a certain unknown threshold, that sinking of salty N Atlantic waters would slow down or stop, and the conveyor current would slow down or stop. If that were to happen, rapid cooling could occur in NE N America & NW Europe, even while global warming continued over the majority of the globe.
Many other researchers predict that the strength of the ongoing warming would overwhelm this salinity/Gulf Stream cooling, however. It remains a controversial theory.
Controversial indeed, but incredibly interesting from a scientific point of view! One theorist who I greatly admire on this topic is hurricane expert Dr. William Gray from the University of Colorado. The great ocean current which Don blogged about is called the "Thermohaline Circulation". It actually stretches across our entire planet from ocean to ocean. Gray says the changing salinity of the ocean water is responsible for the earth's warming or cooling. He says there have been times in history when the earth was even warmer than it is now. It's a natural, cyclical process, and he says eventually we'll head back into a cooling period when the thermohaline circulation slows down. The last time I heard him talk at a weather conference earlier this year, he said that we would undergo cooling again in the next 20 years. Hope we won't have to wait that long to see the "old fashioned winters....think snow!
Isn't global temperature basically like a pendulum, swinging from one end to the other over time? I've read that scientists believe that we have had several Ice Ages and warming periods over the millenia, and that some of the current phenomena attributed to global warming could, in fact, be attributed the normal cycling of global temperature. Not to discount the damage we do with our SUVs and coal-burning power plants, but it seems like global warming, to some degree, would be happening anyway.
-Mike
I hope we get alot of snow this year. We are 8th grade students at Alden Middle School and we are studying weather patterns this marking period. Our teacher and us are all hoping for lots of snow, especially for christmas!
I am an 8th grade student from Alden Middle School, we are studing weather now. Our teacher and us are hoping for a lot of snow to go outside in. :] I would just like to say, I hope we have tons of snow this winter! It will be good for the holiday season!
Mike,
Global warming and cooling cycles have occurred with no connection to humankind throughout the earth's history. However, there is strong evidence that the ongoing warming is connected by an unknown percentage to human (anthropogenic)activities and our greenhouse gasses. The rapid warming which has been occurring does parallel the modeled predictions of recent decades based on parts per million of CO2 increases.
Dr. Gray, whom Mary Beth mentioned, may yet be proven right. However, at this point his view is an "outlier" among climatologists, atmospheric chemists and physicists, and meteorologists engaged in this type of research. Most in this field believe we would not be in this period of accelerated warming without the increases in greenhouse gasses produced by anthropogenic activity--in other words, it's not "all natural."
Alden 8th grade:
I'm with you! I like snow just as much as I did when I was your age. But I can't get too happy about on the air, because the adults who hate it then start to subconsciously blame me for it! (Even my late dad used to grumble, "YOU don't have to DRIVE in it....)
I must say I agree for the most part with Dr. Gray who is skeptical of current theories of human-induced global warming. I strongly believe global warming is the result of the natural cycle of ocean water temperatures—related to the amount of salt in ocean water. That same cycle means a period of cooling would begin soon and last for several years. Throughout history, there have been ice ages as well as periods of global warming. Isn't this proof enough? Gray says we shouldn't mess with industrialism. I wouldn't go that far, since CFCs and other human-induced activities help corrode the ozone layer. (Yes, by all means, we need to be kinder and gentler to our environment)...but to say that humans are responsible for total planet global warming is just ludicrous. The earth is just too big of a place!!
As you can see, we encourage the open exchange of ideas on this blog. Since Global Warming can tend to be a controversial topic, I hope those of you who wish to learn more about the complexities of this issue visit this link: www.ncdc.noaa.gov/oa/climate/
globalwarming.html
This link will take you to expert information prepared for the public at the National Climatic Data Center, a branch of NOAA, your National Oceanic and Atmospheric Administration. To put it bluntly, this government agency does not have a philosophical "axe to grind" and I think you'll find it very informative as a starting point.
P.S. on Global Warming links...
Here's another, provided by NASA's Goddard Space Flight Research Center:
http://gcmd.nasa.gov/Resources/
pointers/glob_warm.html
This single link will offer you many other links which provide scientific background on Global Warming and anthropogenic influence. (Note: one link to "An Incovenient Truth" may show perceived bias, but the others are to recognized sources of great expertise).
I offer these links only as an opportunity for some education in an enormously complicated subject area. Some of it is heavy reading, true, but rather than take you to links offered by "activist" groups, I think it's a good idea to seek expert opinion from scientific bodies whose work stands up under peer review. That's a major part of the scientific method.
"THIS JUST IN" as they say in this business....NASA and other sources have reported this week that China has now passed the US as the biggest producer of CO2, at least 2 years ahead of schedule.
And, since automotive sales are skyrocketing in China, and that government has more than 500 fossil fuel-fired power plants scheduled to be built in the next 5 years, they're going to be leaving us well behind.
Not exactly good news in the department of anthropogenic warming.
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