Why are we so bad at long range weather forecasting?

By WUWT regular “justthefacts”

In researching the use of tidal forces in long range weather forecasting, I came across an interesting August 30th, 2010 Associated Press/ MSNBC article based on interviews with Farmer’s Almanac Editors Sandi Duncan and Peter Geiger, and Ed O’Lenic from NOAA’s Climate Prediction Center:

“Good news, winter haters: After record snowfall in the mid-Atlantic and unusually cold weather down South, the Farmers’ Almanac is predicting a “kinder and gentler” winter.

After eyeing the skies, tidal action and sunspots, the folks at the 194-year-old publication say in their 2011 edition going on sale Monday that it’ll be cold but nothing like last winter, when 49 states saw snow and it got so cold in Florida that iguanas fell out of trees.

“Overall, it looks like it’s going to be a kinder and gentler winter, especially in the areas that had a rough winter last year,” said managing editor Sandi Duncan.”

“The Farmers’ Almanac, which claims 80 to 85 percent accuracy and says it correctly forecast heavy snow in Middle Atlantic states last winter, bases its predictions on a secret mathematical formula using the position of the planets, tidal action of the moon and sunspots.

Ed O’Lenic from NOAA’s Climate Prediction Center said the scientific community doesn’t accept tides, planetary alignment and sunspots as effective predictors of temperature or precipitation, but he stopped short of calling the almanac’s meteorological methods a bunch of hooey.

“In science you have to have an open mind. Someday, someone could conceivably find some scintilla of evidence that it’s useful,” O’Lenic, chief of the operations branch, said of the almanac’s methodology. “For the time being, we have to stick with what produces results for us.”

“For the record, NOAA’s Climate Prediction Center anticipates a warmer-than-normal winter for the mid-Atlantic and Southeast and colder-than-normal weather in the Northwest. That puts it at odds with the almanac, which calls for mild temperatures in the Northwest and cold in the Southeast.”

Here’s the October 21, 2010 Winter Outlook from NOAA’s Climate Prediction Center:

“The Pacific Northwest should brace for a colder and wetter than average winter, while most of the South and Southeast will be warmer and drier than average through February 2011, according to the annual Winter Outlook released today by NOAA’s Climate Prediction Center.”

“Northeast and Mid-Atlantic: equal chances for above-, near-, or below-normal temperatures and precipitation. Winter weather for these regions is often driven not by La Niña but by weather patterns over the northern Atlantic Ocean and Arctic. These are often more short-term, and are generally predictable only a week or so in advance. If enough cold air and moisture are in place, areas north of the Ohio Valley and into the Northeast could see above-average snow”

“Florida: drier than average, with an equal chance for above-, near-, or below-normal temperatures.”

“Central U.S.: equal chances of above-near-or below normal temperatures and precipitation”

Here’s Accuweather’s September 8, 2010 forecast:

“Wintry Battle Zone But No Snowmageddon

In general, the East Coast will be granted a reprieve from the tremendous snowfall that caused 2009-2010’s winter to be dubbed “snowmageddon.”

This does not mean a free pass for the Northeast. Bastardi predicts late November and December could get winter off to a fast start in the East, with a major thaw coming for much of the country in January.

Bastardi makes the early cold connection between this year’s active hurricane season and his winter forecast.

He said that years that see significant landfall, such as 1995, 2008 and 2005, usually also have cold for much of the eastern and central portions of the nation in December.

He said this year from the central Rockies to the Northeast a higher variance of temperatures will be present – “greater-than-normal swings between winter’s coldest and warmest days.” The conflicting warm and cold air masses contributing to these temperature fluctuations have placed this area into what Bastardi calls the “Wintry Battle Zone.”

Despite the wild swings in temperatures, cities like New York, Philadelphia and Washington, D.C., will still have near-normal snowfall. To put this in perspective, New York City receives an average of 28.4 inches of snowfall during winter.”

Here is the Old Farmer’s Almanac Atlantic Corridor Annual Weather Summary :

“Winter will be colder and drier than normal, on average, with below-normal snowfall in New England and above-normal snowfall elsewhere. The coldest periods will be in mid-December, January, and mid-February. The snowiest periods will be in early January and mid- and late February.”

Hmmm, “with below-normal snowfall in New England”. According to this January 28, 2011 Boston Globe article January 28, 2011 Boston Globe article “In Somerville, New England’s most densely populated city, some snowbanks are so tall that they deflect the plume of snow cleared by plow trucks and send it sliding back down to the street, said Michael Meehan, a city spokesman. Between storms, crews have been trying to clear snow piles and dump them on basketball courts, while the real estate trust planning a 50-acre redevelopment at Assembly Square has offered the city private land for use as a snow farm.”

In terms of The Old Farmer’s Almanac forecast that “The coldest periods will be in mid-December, January, and mid-February.” here are Weekly Mean Temperatures for the Northeast:

Week-Ending | Mean Temperature | Anomaly

20101204 | 33.76 | 0.90

20101211 | 26.15 | -4.02

20101218 | 23.80 | -4.01

20101225 | 22.68 | -3.12

20110101 | 24.45 | 0.35

20110108 | 24.73 | 2.00

20110115 | 22.28 | 0.37

20110122 | 20.86 | -0.54

20110129 | 19.89 | -1.64

20110205 | 19.93 | -2.15

20110212 | 20.84 | -2.22

20110219 | 25.70 | 1.20

20110226 | 26.21 | -0.20

20110305 | 28.28 | -0.41

Source: National Oceanic and Atmospheric Administration (NOAA) – National Climatic Data Center (NCDC):

I guess that you could call December 5th – 25th “mid-December”, but the first half of January had the warmest anomaly of an otherwise freezing winter and “mid-February” i.e. Feb 13th – 19th, was actually the only positive anomaly in the month of February.

Here are all of the Old Farmer’s Almanac Regional Annual Weather Summaries:

Note that you can verify the veracity, or lack thereof, of many of the weather predictions on the new WUWT US Weather History Reference Page:

And let us not forget about the UK MET Office who are apparently still trying to figure out what their forecast was, or at least what they renamed it and where they buried it on their website;

http://autonomousmind.wordpress.com/2011/02/01/met-office-document-shows-it-only-renamed-its-seasonal-forecasts/

http://wattsupwiththat.com/2011/01/11/the-plot-thickens-bbc-hits-uk-govt-with-freedom-of-information-demand-in-cold-winter-forecast-fiasco/

http://wattsupwiththat.com/2011/01/04/the-met-office-bullhockey/

but, according to this October 28th, 2010 article in the Telegraph;

“Although the Met Office no longer issues long-term forecasts, their latest data suggest a high probability of a warmer winter for London, the East of England, Scotland and Northern Ireland.

The South West, Wales and most of the North of England are less likely to enjoy such relatively pleasant temperatures but still have a 40 to 60 percent chance of being mild.

The statistics were generated by the Met Office’s new £33million supercomputer built by IBM.

Forecasters used it to analyse how likely temperatures and rainfall were to be above normal for winter but not how far above.

Related Articles

The average temperature for winter from 1971 to 2000 is 3.7C (39F). However, last year was 1.5C (35F), meaning anything above the 30-year normal this winter would be a marked improvement with far less chance of snow and ice.

As well as the milder winter, the computer concluded that almost all of Britain had a 40 to 60% of being drier than normal, with only the south coast more likely to see normal amounts of rain.”

How bad was the MET Office’s forecast? Per this March 4th, 2011 Article in Farmers Weekly Interactive;

“Britain’s worst winter weather for 100 years will cost farmers more than £100m, a Farmers Weekly investigation has revealed.

Farmers across the country have been left counting the cost of lost crops, collapsed livestock buildings and burst pipes.

Rural insurers said 2010 would go down in history as the worst year on record for cold weather claims.

Among the worst-hit are England’s 4000 sugar beet growers. Temperatures plunging to -13C in December followed by a mild and wet January left £52m of sugar beet rotting in the fields, according to Farmers Weekly calculations based on British Sugar figures.”

In summary, the long range forecasts of the Farmer’s Almanac, NOAA’s Climate Prediction Center, the Old Farmer’s Almanac, Accuweather and the UK MET Office all appear to be suspect. Why?

Advertisements

  Subscribe  
newest oldest most voted
Notify of
P Walker

Why ? Because they’re not using wooly worms .

Engineer Bob

Why is predicting weather 3..6 months in advance so hard?
Weather is notoriously chaotic, from a mathematical perspective. Non-linear relationships with feedbacks on many timescales — *of course* it has sensitive dependence on the initial conditions and ongoing inputs.
I’m reading a textbook on Thermodynamics that was old fashioned when it was written 50 years ago. They could hand-calculate the limiting cases, but had to throw up their hands on anything realistic. I actually find that refreshing, and am in awe that they could design power plants with just the accuracy they could get on their slide rules. Nowadays, people just throw the whole thing into a computer and believe the results. It’s partial differential equations, after all, and they have a solver. What could go wrong?

Carl Chapman

It’s hard to predict exactly what a chaotic system with non-linear feedbacks will do.
If you build faulty assumptions about CO2 into your system, it’s even harder.

T Braunlich

Not only have they been way wrong, but they seem to have been consistently wrong the last several years. That suggests to me that the methods they are using might not be as well founded as they think they are.

Engineer Bob

What is the predictor’s “skill”?
Why not accumulate statistics and see.
I’ll grab the easy one. I predict that today’s weather is the same as yesterday’s. I’ll miss all the changes, but, counting successful predictions, my statistics may be higher than a predictor using actual intelligence.
Same thing for annual predictions. Compare the forecaster’s results to the null hypothesis.

littlepeaks

Could it be that there are some truly random processes involved, that make long-term weather forecasting impossible?

Dennis Sharp

More details concerning the chaos of weather:
All chaotic systems have a strange attractor, and I have never seen anyone make a strange attractor of temperature, precipitation, or the number of fronts passing a location in a year. Everyone acts as if the weather acts according to some secret equation that only they know, when in fact, it is merely tracing paths in its strange attractor; and no one knows exactly what path it will take. However, it is only a matter of detail. I can accurately predict that January in the northern hemisphere will be cold and July will be hot, but I can’t predict exactly which days in January will be below zero in Colorado or which days will be above 100 and July in Colorado. All the weather forcasters are trying to push the boundaries of the amount of detail they can predict. They just need to stop trying to put more and more variables in their equations and concentrate on finding strange attractors of whatever they are trying to predict. That is the signature of chaotic systems.

Mike Bromley

Not that the soothsayers are unwilling to open their mouths to change feet! If you cover enough bases, your prediction has a 0-100% chance of being right!
Isn’t that what is being done by constantly changing the root “concept” to fit the data?

James Sexton

Because we don’t know what we don’t know. Our level of understanding our climate, or long term weather, if you will, is very poor.

Jeff K

My definition of arrogance: the inability to acknowledge how ignorant you really are. No statement is truer than, “the more you know, the more you realize you don’t know,” unless arrogance gets in the way.

Jimbo

They’re bound to get it wrong sometimes. The question should be what is each one’s level of accuracy in percentage terms?
The Met Office gave up on seasonal forecasts for the public probably due to their computer’s warming bias. The people of Britain are now grateful that they don’t have to endure anymore misleading forecasts. The government and other organisations who subscribe to there nonsense were mislead this past winter too.
http://www.bbc.co.uk/blogs/paulhudson/2010/01/a-frozen-britain-turns-the-hea.shtml

Curiousgeorge

It’s said that prostitution is the oldest profession. I think prediction is. Or maybe that’s a distinction without a difference.

Don K

Old Farmer’s Almanac Atlantic Corridor Annual Weather Summary :
“Winter will be colder and drier than normal, on average, with below-normal snowfall in New England”
NOAA’s Climate Prediction Center: “Northeast and Mid-Atlantic: equal chances for above-, near-, or below-normal temperatures and precipitation. … Northeast could see above-average snow”
Here’s Accuweather’s September 8, 2010 forecast:
“Wintry Battle Zone But No Snowmageddon
In general, the East Coast will be granted a reprieve from the tremendous snowfall that caused 2009-2010′s winter to be dubbed “snowmageddon.”
====
Burlington, VT winter snowfall total as of last Sunday = 128.0 inches – third snowiest Winter on record. May still creep into second place as there is sometimes appreciable snowfall up here as late as mid-May. Cold? 6594 heating degree days vs normal 6718. So, a bit warmer, with much more snowfall than usual.
Old Farmers Almanac and Accuweather — Prediction wrong on all counts. NOAA — unspecific, but less awful. I reckon I could do about as well with a table of random numbers, a ouija board, or a magic eight-ball.

Engineer Bob

@justthefactswuwt: Thanks for the link to the NOAA skill page.
It looks like they have a bug in their script. They are obviously updating the *headings* periodically to reflect the current date, but the *data* stops at 2007 as you said.

Colonial

It’s difficult to grasp data for a number of sources (e.g., the Old Farmer’s Almanac, NOAA, Accuweather, etc.), especially when each is associated with a number of variables (in this case, predictions for various portions of the winter). It would be helpful to organize the data as a table and include “Reality” as a source, showing what actually happened. This would make comparisons between the sources easier, and would show trends that are lost in the verbiage.

izen

It is relatively trivial to make correct predictions about the future climate as long as you restrict such predictions to very large areas (nothing smaller than a hemisphere) and long timescales – nothing shorter than a month.
As another poster pointed out, there is no problem with predicting that July will be warmer than January in the Northern hemisphere, its when you try and predict the conditions in an area of less than 20% of the Earth’s surface for less than 5% of the year that major errors arise.
As others have suggested this is because local weather is a chaotic process – lots of no-linear effects interacting. But lower resolution predictions CAN be accurate about such chaotic systems because they deal in boundary conditions rather than specific or initial conditions.
An example invoking one of the simplest chaotic systems may help clarify.
The dripping tap may seem to be a simple periodic system, the drips occurring regularly with the same size according to the input flow and the size of the spout. But when measured accurately the timing of the drips and their size is NOT regular, it is chaotic with the values for drip size and the period between drips fluctuating by several percent in a deterministic but chaotically unpredictable manner. While there is some autocorrelation between drip size and time for a series of drips, it is inherently impossible to predict the exact time and size of the next drip given the size and time of the last seven. (any similarity with ENSO cycles is purely educational)
But given the flow rate and spout size it IS possible to predict the average size and timing for 1000 drips. Despite the chaotic nature of individual drops, the long term consistency of the system makes it possible to use the system as a clock as the development of water-clocks based on this principle in several civilizations shows.
It is also possible to predict the average size and timing if the flow rate or spout size changes. That will alter the average size and timing of drips, but will not make it any easier to predict the size and timing of individual drops.
Weather and climate – and the prediction of each have similar features to the dripping tap. Individual drops are like the weather, they will vary within a range and be chaotic, but climate is like the average size and timing of drips over MANY individual events, it shows consistent results for a given level of input and process. In one case water pressure and spout size, in the other energy input and thermal emission pathways.

ferdberple

“I can accurately predict that January in the northern hemisphere will be cold and July will be hot, but I can’t predict exactly which days in January will be below zero in Colorado or which days will be above 100 and July in Colorado.”
This is the Uncertainty Principle in particle physics, as applied to large scale object. You can know “what” OR “when”, but you cannot know “what” AND “when”.
Nathanael Herreshoff, the father of modern yacht design applied this to boats. You can have speed, comfort and low-cost. But never more than two at the same time.

Paul Vaughan

“The Pacific Northwest should brace for a colder and wetter than average winter”
Was a warm winter here.
(A lot of people thought it would be cold because of linear misconceptions about the nature of relations with other indices such as SOI, N34, MEI, & AAM.)

stephen richards

izen says:
April 9, 2011 at 11:21 am
Yes but they are useless predictions. The whole purpose of predictions is avoidance. If you cannot be specific in where, when, how much and how and WHY, it’s useless. It might be approximately right in one aspect and completely wrong in another. If the climate of southern spain is warm in this epoque I assume you think that is climate prediction but in spain, costa del quoi, it snows sometimes. If a climate prediction cannot tell me whether that snow will become more persistent then it is useless and climate models cannot provable predict in any way shape or form so they are useless and should be shut down right now.

rbateman

Why? The GCMs, upon which the aforementioned mis-forecasts are based, come pre-polluted with a warming bias (or trend). The result is one of two foregone conclusions:
a.) The warming trend continues in nature and the GCM’s are along for the ride or
b.) The cooling trend replaces the warming trend and the GCMs are lost in space.
The GCMs are computer programs incapable of dealing with climate that is not warming.
Contrast the GCM based results with a real metorologist who cracks the books.

George Turner

P Walker nailed it with the first comment, and wooly worms are much cheaper than supercomputers.

Bigdinny

Forget the long term forecasts. Why are we so bad at the short term? My father was an avocado grower, and for a while subscribed to a weather service who advertised an 85% accuracy of prediction. He quickly realized that they ensured their accuracy by constantly making revisions and issuing updates. He finally threw his hands up in the air (there was no CO2 then to harm him) and said, “Hell, I don’t need to pay somebody to look out the GD window. I can do that for free myself.

Gary D.

Never make predictions, especially about the future.
– Casey Stengel

izen

@-stephen richards says:
April 9, 2011 at 11:38 am
“Yes but they are useless predictions. The whole purpose of predictions is avoidance. If you cannot be specific in where, when, how much and how and WHY, it’s useless. It might be approximately right in one aspect and completely wrong in another. ”
Unfortunately it is inherent in the nature of chaotic systems that the level of detail you demand is impossible. It is like asking for the ability to predict the size and timing of an individual drop.
The only possible predictions for such a system put constraints on the RANGE of values for drop size and time, and can give the probability distribution for that range in some circumstances. The boundary conditions – but it cannot give you predictions that are useful for avoidance of specific events.
-“If a climate prediction cannot tell me whether that snow will become more persistent then it is useless and climate models cannot provable predict in any way shape or form so they are useless and should be shut down right now.”-
Again it depends on the climate model and the resolution of the prediction.
It will never be possible to tell you how much snow you will get at a certain location during a certain month. But climate models using pen and paper (and maybe a slide rule) are capable of predicting the cooling from major volcanic eruptions.
Direct observation of the cooling after Agung El Chichon and Pinatubo combined with measurements of the solar dimming from the stratospheric emissions has provided an objective measure of the magnitude and duration of the effect of such volcanic events.
This will not satisfy the level of detail you are demanding, but the knowledge that a volcanic event of a certain size will reduce surface temperature by a certain amount for a certain time (with probability ranges) is still useful information for those that need to plan for future heating fuel use or agricultural productivity changes at the global or continental level.
The difficulty in predicting the timing and magnitude of the ENSO changes indicates the problem with specific predictions. But the 1LoT constrains the balance of positive/negative events so that the prediction that the overall effect on temperature for many cycles will be neutral.
The equivalent of the water flow rate for the dripping tap constraining the amount of water that drips over many events.

commieBob

Anybody know how Piers Corbyn did?

dp

The evolution of weather in New England is dependent upon the evolution of weather over many degrees of longitude to the west, and over many degrees of latitude to the south and north, and that weather is dependent on the evolution of weather over many degrees further west, north, and south and so on until we’ve circled the globe.
This continuous evolution is energized by the sun in a self-modifying way that impacts its own evolution, principally as a result of phase change of water. A snapshot of the global state is climate and that is changing moment to moment within the constraints of the existing state (and which is also changing moment to moment). The climate tomorrow cannot become what the constraints of today prohibit. Regional snapshots are what humans call weather. Weather can be anything allowed by the constraints of the climate state and cannot become tomorrow what today’s state prohibits.
Phase change creates step changes in the rate of change as evidenced by increased or reduced albedo, cloud cover, precipitation, glaciation, glacial lakes, and sea level changes, and where, in the system, these changes take place. There is a hell of an interesting story in the history of the Caspian sea, for example. The flooding of the Mediterranean sea is another epoch climate changer. It would be difficult to imagine either history is independent from phase change of water in the environment.
Geologic features such as mountains, land masses, and plate tectonics can influence the consequences of constraints of the current climate and so the future of the climate. There are ocean and atmospheric patterns that emerge from current geographic and climate state conditions (middle latitude deserts, for example) and these patterns change as climate evolves. Imagine how different the global climate would be if the isthmus of Tehuantepec or the isthmus of Panama were to open naturally allowing free flow of equatorial water between the Pacific and Atlantic. Same with the great rift valley of Africa. My estimate is if there were a significant equatorial path between the oceans the poles would freeze like we’ve never seen. Oddly, that could result in sea level dropping, cutting off the equatorial exchange, completely isolating the oceans. That is just a fun mental exercise, btw.
In fact there is no regional weather that is independent of global weather, but that is not what populates the weather page in the NYT. People need to see and predict local weather and much money is wasted trying to predict well into the future what that weather will be. That is a fool’s errand.
Or not. I invent, you decide.

1DandyTroll

“Why are we so bad at long range weather forecasting?”
Because the hippies are diluting the population?! :p

Latitude

a 40% – 60% chance…..that’s the same as saying a 50% chance which is no chance at all
either it does or it doesn’t, we don’t know…..
above – near – or below normal???
People actually get paid for this?
If this is what they consider a forecast, then they are not able to forecast at all……………

David O.

This spring, the forecast (one day in advance) was for 6 inches of snow. We got 22 inches. The next blizzard, the forecast was for 2 inches of snow. We got 8 inches. Even next day forecasts are suspect in my opinion, and when you can’t forecast one day forward, how are you going to forecast 5 days or longer.

Bigdinny

My farmer father also said that the temperature and rainfall always averaged out over the course of the year. So if you had a cold, wet winter expect a hot dry summer. A “normal” winter generally meant a “normal summer”. And by my observation, the notion is generally spot on. I think that’s why I continue to read the Farmer’s Almanac. Even when it’s wrong it’s entertaining.

Pete Olson

I’m with Commie Bob: How did Piers Corbyn do?

anthony holmes

Well , the UK met office are consistently right by their long range forecasts , its just that you have to know how to ‘read’ them properly – as in whatever they say it will be the opposite . Everyone in Britain knows this and uses their information properly . If they ever tried to get the forecasts right it would cause absolute chaos as people wouldnt know what to think !!
We should all know that the weather forecasters are just guessing and really havnt a clue – we want them to know , we think that because they get paid good money have degrees and get to play with multi million computers then they ought to get it right – but really they really havnt a clue as to what will happen in the future – but they cant say so or they will be out of a job !!!!

Joe Bastardi

Okay, first of all, the Jan cold lasted, but the idea of the cold, rip roaring start was darn good and the warm Feb was good too.
That doesnt excuse me from Jan that was cold, in spite of the AO flipping almost right on time. And missing here is the fact that in late December I made darn sure people knew I had changed the Jan idea to cold… also missing is the forecast from the year before which talked about HOW WILD WINTER WOULD BE, more so than other sources.
Interesting, since the idea of the winter battle zone was stressed and in battle the line fell about 100 south of the forecast so we got the snow and cold down to PHL.. NYC was never going to get off scott free and the lakes and New England were supposed to have a nasty winter.
I find it interesting people dont mention what happened in DC and places in the mid atlantic that had less than 25% of the snowfall of the year before.
Again, Jan was the kind of problem I had in Jan 2006…. though opposite.. but having the winter coming hard out of the gate and a Feb that would be nothing like last year, which WAS THE MONTH OF THE WINTER. There was supposed to be a huge fight with a winter that started cold and ended on a warm note… and while certainly not perfect if you actually look at what happened, that was merit.
The last La Nina winter in 07-08 was a non winter in the northeast and that certainly was not the forecast this year.
BTW, yes the 10-15 days of brutal cold into the deep south was not seen before hand. But instead of picking out pieces of what I said, I notice that no one bothers to
talk about how I was concerned about the winters of 16-17 and 17-18 with low solar and northern latitude volcanic activity as my big worry. Problem is one does not have the charts needed to form a concrete idea on these things, but at the least one could see my concern.
And by the way, just what was wrong with forecasting the brutal cold start in nw Europe and then saying it would reverse. In fact, I parted ways in a major manner with people I have formed an alliance with on AGW debates on that issue, saying it would collapse in the nw after December when many were waiting for the other shoe to drop, or had not seen it at all. Sadly, the mid and late winter cold never cranked until too late in the east ( Russia)
There are big things going on now, and WUWT and many of the more open minded blogs on the climate issue are making sure you see them. However I can not control what you read from me. While I agree, there were places where the winter idea came up short, the December idea, which I am very sensitive to credit since it is from a theory of my dads on late hurricane seasons in the southwest atlantic basin and why December is cold in the east, and I harped on that constantly from summer in my writings, and then the warm Feb OPPOSITE OF LAST YEAR in the east, and the battle that developed ( battles lead to storms) I think should not make the forecast go down as a washout, though it was not what I expect of myself!
On Nov 26th, saying 50% of the nation would be covered by snow on Christmas day
and having it 50.3% should get some consideration also. That is not an easy forecast to make
peace and out
JB

The reason the long range (monthly and seasonal) forecasts are often incorrect is simple atmospheric chaos and inputs from outside the atmosphere (solar, volcano, etc.) are unforseeable. The latter don’t matter much in day-to-day forecasting.
That said, weather forecasting out to three days has become markedly more accurate for periods of three days and less the last 15 years. To see the figures go here: http://www.geography.osu.edu/metclub/symposiuminformation.htm and downloade Jim Hoke’s presentation.
Or, to learn how storm warnings (short term forecasts) are saving lives by the thousands, I’d modestly like to suggest my book, “Warnings.” While a true story, it is written like a mystery novel and tells the story of how we unraveled everything from Category 4 hurricanes to F-5 tornadoes. It has received superb reviews. Details here: http://www.amazon.com/Warnings-Story-Science-Tamed-Weather/dp/1608320340/ref=sr_1_1?s=books&ie=UTF8&qid=1283787949&sr=1-1

Agile Aspect

Regional weather forecasts are typically valid for roughly 3-4 days. I always presumed it because meteorologists assumed an adiabatic atmosphere – or adiabatic equations of state. But I really have no idea.
I find the Farmers’ Almanac interesting because it’s based on observation but the hard part is trying to figure where the Moon was and which part of the ocean cycle they were in when the information was recorded.
We can’t even solve the heat equation (a simplified form of the Navier-Stokes equation) on a rotating 3 dimensional sphere alternating between between cold and hot.

Caleb

We’re not bad at forcasting. It is forcasting correctly that is hard.

Crispin in Johannesburg

When a few months ago I bought a new Farmer’s Almanac written specifically for Canadian climate regions I was very disappointed to find they have tossed their long term forecasting method and replaced it by some warmist who crowed about ‘a computer model’. The book was $6 worth of guff.
And to think that last year things were done so well.
Please, FA, an AG warmist and a computer GC model are not a good substitute for skill and knowledge. You just lost my custom.

No simple answers to complex questions. The simple answer to your simply stated question is simple. Ignorance, chaos and Mother Nature plays her weather game with loaded dice.

kalsel3294

The degree to which accurate long range weather forecasts can be made lies with how far out SST’s can be accurately predicted.
Some researchers seem very close to being able to do so looking 2 years ahead, and those analysts who base their seasonal forecasts on such relevant projections are increasingly able to consistently produce reliable forecasts. The general public who rely on the public weather services may not see much evidence of this, but those individuals and corporations who are prepared to pay private weather service providers for their expert, and specific analysis quickly decide whether they are getting value for money or not.

Don’t forget there is a difference between the “Old Farmers Almanac” and the “The Farmers Almanac”
Their 2010 forecast was:
…a winter during which temperatures will average below normal for about three-quarters of the nation….
…Near-normal amounts of precipitation are expected over the eastern third of the country, as well as over the Pacific Northwest and Northern Plains, while drier-than-normal conditions are forecast to occur over the Southwest and the Upper Midwest/Great Lakes.
Only the Central and Southern Plains are expected to receive above-average amounts of precipitation.

http://www.farmersalmanac.com/frigid-2010-weather-outlook/

william gray

Anyone know that Australian mob who have an 83.9% accuracy for long range forecasting. I know they include solar and plannetry activity, OHC etc?
I remember that they have a long line of forecasters going back to the 1840,s.
My computer crashes regularly, and I know save links on a memeory stick.

william gray

Found something this is the Mob.
http://www.abc.net.au/landline/content/2006/s1729787.htm
Yeah I saw the ‘shpelink’ mistakes.

william gray

From the link previously:
SALLY SARA: And what about the issue of climate change? Can we expect drier times ahead because of the changing climate?
HAYDON WALKER: No, I don’t think so. I mean, like with the global warming and so forth, all these conditions have happened before the Industrial Revolution. If you go back into the 12th, 14th, 15th centuries, all these catastrophes of weather and so forth have happened before the Industrial Revolution. It’s disgusting what goes into our oceans, it’s disgusting what goes into our waterways and what we put into the atmosphere, but I don’t think that the global warming is affecting the weather like the “experts”, so to speak, are saying.

wayne Job

With satellite imagery and storm tracking 3 to 5 day forecasts have become better but only in a regional sense. The smaller the target area the less chance of being right.
Long range regional forecasting is all but impossible with any degree of accuracy for there is nothing linear about the weather.
If all the pre-conceptions of the climate models were erased and all the cyclical knowns from ice cores, bore holes,geology ,raw temp data from long term thermometers and all other useful cyclic data such as solar and planetary mechanics. This would give our super computers something useful to chew on. The output would give us our place in the cycles and be useful on a decadal ,century and millenium scale.
They are at the moment p#@@ing into the wind and getting back on their faces.

BenfromMO

I have been doing long-term weather predictions for awhile now. When I say awhile, I do mean just shy of 2 years, and I can attest to the difficulty in getting in correct all the time. I am probably around 80% for Missouri and around 60% or so elsewhere. This is because most of my weather predictions for outside of MO. are based on extrapolation and anyone who does this realizes how inaccurate that gets and how quickly.
If I had more free-time, I would not extrapolate based on just MO, because as anyone else who does this will tell you, that is a rather poor substitute for locking down jet-streams, and patterns.
FYI, my general prediction for MO:
Spring, VERY rainy slightly cool. (until early June when we hit drought phase. Lots of storms.)
Summer: Very dry and just a little warmer then average. – This leads to the violent storms moving to the south over OK, Ark by early June…Tornado alley..
Fall will be normal. (Temps. and rainfall.) – Late August should start the normal temps/precip.
I make more precice predictions, but that is just my basics..its a tough business.
I got last fall wrong. The winter I nailed for MO.
But I got the SE wrong (both fall and winter) and SW terribly wrong (Winter) and was somewhat correct for Fall. But I did nail New England/East coast in both fall/winter. One of those things….its hard to predict how weather patterns will line up exactly.
Midwest was nailed, but I was slightly wrong for Pacific NW.
I have a lot of work to do obviously. But one thing going for me, this last winter was difficult for everyone (except farmer’s alm. which got the most right)…as a general rule.
Not sure how they predicted the SE US, that was a surprise to me and most others too.
I learned, and I am fairly confident of my predictions for the coming year.
If you notice, I haven’t started work on next winter ( I think its premature still)..
Six months is a general limit I would say overall as anything past that can really go downhill quickly. But preliminary work has shown next winter to be worse then this last (just take that to mean colder at this point.) Again, preliminary, its going to depend on how ENSO goes into summer. Also, tracking other factors is going to be a large job. Overall I tend to look at previous years a lot as an indication.
As a hint, the best year in the past that has corresponded to this year’s weather overall is before my own mother was born. You have to go quite a ways back to find similarities. If that is any indication, Next Spring will arrive early and with A TON of thunderstorms for upper and lower midwest.

Phil.

dp says:
April 9, 2011 at 12:46 pm
Imagine how different the global climate would be if the isthmus of Tehuantepec or the isthmus of Panama were to open naturally allowing free flow of equatorial water between the Pacific and Atlantic. Same with the great rift valley of Africa. My estimate is if there were a significant equatorial path between the oceans the poles would freeze like we’ve never seen.

I think you’ll find that the closure of the Panama gap led to the current era of ice ages.

The future is unknown and will remain unknown. 3-5 day forecasts deal with the present.