I don’t know about you but I’m relieved that the weather won’t be “static”. – Anthony
Contact: Carmeyia Gillis FOR IMMEDIATE RELEASE
301-763-8000, ext 7163 Nov. 20, 2008
NOAA’s U.S. Winter Outlook Calls for Variability
In announcing the 2008-2009 U.S. Winter Outlook for meteorological winter from December through February, forecasters at the NOAA Climate Prediction Center are calling for warmer-than-normal temperatures for much of the central part of the nation, and a continuation of drier-than-normal conditions across the Southeast.
With the absence of La Niña and El Niño in the equatorial Pacific Ocean this season (climate patterns that give forecasters clues about potential weather events months in advance), predicting weather patterns on seasonal timescales becomes increasingly challenging. Instead, other climate patterns over the Arctic and North Atlantic regions may play a significant role in influencing U.S. winter weather.
“These patterns are only predictable a week or two in advance and could persist for weeks at a time,” said Michael Halpert, deputy director, Climate Prediction Center. “Therefore, we expect variability, or substantial changes in temperature and precipitation across much of the country.”
Regional Outlooks
· Northeast and the Mid-Atlantic: Equal chances for above-, near-, or below-normal temperatures and precipitation.
· Southeast: Increased chance of above normal temperatures in the central and western parts, along with below-normal precipitation.
· Central Region: Increased chance of warmer-than-normal temperatures, with above- normal precipitation anticipated in parts of the central Plains.
· Western Region: Equal chances for above-, near-, or below-normal temperatures, and an enhanced likelihood of below-normal precipitation across parts of the Southwest.
· Alaska: Milder-than-normal temperatures except along the southern coast. Equal chances for above-, near-, or below-normal precipitation.
· Hawaii: Above- normal temperatures for eastern Hawaii and below-normal temperatures for western Hawaii. There are equal chances for above-, near-, or below-normal precipitation throughout the state.
The U.S. Winter Outlook does not include a snowfall forecast. Snow forecasts are heavily dependent upon winter storms and are generally not predictable more than several days in advance.
Prepare for winter weather through NOAA Watch, http://www.noaawatch.gov. The site gives you the latest weather patterns, forecasts and warnings issued by NOAA’s National Weather Service. Also, tune in to NOAA Weather Radio All Hazards to get your up-to-the-minute local forecast and warnings.
NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.
On the Web:
NOAA’s 2008-2009 U.S. Winter Outlook:
http://www.cpc.ncep.noaa.gov/products/predictions/long_range/seasonal.php?lead=1
Winter Weather Safety Information: http://www.noaawatch.gov/themes/winter.php
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Looking at how this NOAA forecast has played in the press, I don’t think people understand it very well. These forecasts are relative to 1971-2000 normals. All “above” means is that temperatures are expected to be something like the average of the 10 warmest years in that period. Similarly, “below” means something like the average, or in the range, of the 10 coolest years of that period. And “neutral” is the 10 years in the middle.
The next thing to understand is the way the probabilities work. Take a look at this media representation of the forecast:
http://www.google.com/hostednews/ap/media/ALeqM5jrA_kODE6e2V-Uu2Ps3onm3icrGg?size=m
I’m pretty sure they have it wrong. The “50” in the center doesn’t mean “50% warmer” but simply “50% probability of warmer than ‘normal.’ That’s a big difference in meaning. There is no way that NOAA is projecting that the winter anywhere is going to be 50% warming than normal! If you understand how to read these charts, then you can also calculate the probability of “neutral” and “cooler.” Where the most likely probability is 50, neutral will be 33, and cooler will be 27. So, where there is a 50 percent chance that temperature will be above normal, there’s also a 50 percent chance that it will be normal, or below normal!
The media doesn’t get it, and I wonder of NOAA cares?
There was a study done years ago at a racetrack over who won the most money….the little old lady ‘hunch’ players going with a ‘vibe’ or the scientific systems players with their graphs and charts. The hunch players beat the pants off the ‘experts’. Sounds like some sort of immutable Newtonian law to me. I got a hunch about the coming winter based on the PQ factor (psycho-quotient) of my resident backyard squirrels. They’re insane. See you in April!
Then there is the matter of “skill.” In some parts of the country where there is supposed to be a 50% probability of above normal temperature this winter, the skill is not very good:
http://i34.tinypic.com/zjasxy.jpg
The NOAA forecasts are poor, and consistently so. I have been following the NOAA ENSO evolution site for some time.
http://www.cpc.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
If you haven’t visited it, and you live on the west coast of the US or like to ski in Washington,Idaho, B.C., or Alberta you should check it out. It is updated weekly and this is my second season following the trend. It is the single largest driver of the quality of my ski season. A weakly negative Index number say between 0 and -0.5 is about right for us. We don’t like a lower that -1.5 index either.
Here is this site’s outlook from Monday of this week. Looks a lot different…
The image is on page 29 of the above PDF. It is the NDJ 3 month temperature outlook. Note the flip flop of temperatures anomalies from the south of Alaska to the north of Alaska for the DJF shown by Anthony above. They predict a warm Alaskan winter…
Basil (16:02:40) :
Umm, I don’t know. I sent Joe a note, but when he’s busy he doesn’t reply. If he does, I’ll pass it on.
I really don’t understand that graphic. Exactly how is a 50% probability of being warmer than normal different from an equal chance of being warmer or colder?
And wouldn’t a 33 percent probability of being warmer mean there would be a 66% probability that it will be colder or normal? I think that graphic shows exactly the opposite of what they intended it to show.
Try making your own seasonal climate predictions for where you live, and you will find out how bad your predictions will be. I live in the Northern Plains and I looked at what happened in the past in my area when the PDO has been strongly negative as it has been all of this year. Since 1935, this has happened about 10 times. For winter temperatures, 5 of the years were well below normal and the other 5 were well above. So which extreme do you chose for a prediction? For Precipitation, half were normal precipitation and the other half where well above normal. (Good news for our drought.)
My point is that it is easy to throw darts at NOAA and their probabilistic outlooks. I admire the fact that they admit that when they go with their “Equal Chances” outlook, they are basically saying that they have no skill in their seasonal prediction. I know that I don’t have much skill. The problem is that some important factors that shape the predominant weather patterns are only at best predictable for two weeks in advance. Madden Jullian Oscillation is an example of such a factor.
I know that CPC, in times of low skill, now prefers to use trends instead of normals. The last 10 years have been warmer than normal during the winter across the Northern Plains. So the last few years, CPC has gone with a higher probability for warmer than normal tempatures. For the most part, this has worked out really well…especially a year in advance. The one problem with using trends is that CPC better have a good feel about what is causing the trend. If I were to ask CPC as to what the cause of the trend is, I suspect most of the staff would say AGW privately. Publicly, I’m not so sure they want to get into that debate. I personally think that part of the trend is caused by PDO/AMO oscillations. In addition, their predictions are verified against temperature data that are not corrected for UHI.
Maybe the NOAA outlooks need a different focus. Maybe they should provide odds for drought/prolonged flooding rainfall. How about odds that winter temperatures will be a standard deviation or more below normal. These are climatic events that impact the public and would be great to give them a heads up. This is done with Hurricanes via Dr. Gray and NHC. They are not perfect, but they help people start preparations.
Well, so far their temperature map sucks. Supposed to be a balmy 15 degrees F here in MO tonight.
Basil, go over to ICECAP and send Joe an email. He usually replys to me in a day or two.
Well we had a chilly day here in Boise. I think we tied with a year in the 60’s But that really was weather. A big wild wind came through and blew away our California smoke inversion and cooled us down:) Mystified up our weather casters greatly. We havent had snow in the mountains locally yet. The skiers are bummed. Someone may have stole our snow:P But so far the Farmers A. is right on.
Hey…..How long does it take for fire smoke to be taken out of the atmosphere. Could the let it burn policy be a factor in the rising Co2 content? Is that considered manmade? I know many places adopted the practice in the late 60’s early 70’s. Would ya be able to tell the difference between factory and fire emissions?
‘There’ll be no change if it stays like this.’
By the way, is there any more ignorant and arrogant title for a bureaucracy than one that claims to ‘administer’ the atmosphere and the oceans?
Ric, MattN,
I’ll send Joe an email.
My numbers in the example I gave above about how to read these charts didn’t add up correctly, so I’ll try again. Where the most likely probability is 50 percent, the neutral case is 33 percent, and the least likely case is 17 percent (not 27 percent). It is still true, however, that there is a 50 percent chance (33+17) of normal or cooler temperatures.
Maybe a better case would be to call attention to the 40 percent contour. In this case, there’s a 60 percent (33+27) chance of normal or cooler temperatures. Sure, the greatest single chance is (supposedly) for warmer temperatures, but overall the chances are greater for normal or cooler temperatures.
So these charts are not really saying what people are making them out to say.
Then, as I said also, there’s the matter of “skill.” NOAA issues these kinds of forecasts, for 0.5 to 12.5 months out. How often are they right? In the graphic I presented above, the “skill” in eastern Kansas is just 0.05, meaning that one time in 20 these forecasts turn out to be better than what could be obtained just forecasting “EC” (equal chances of above, normal, or below normal temperatures). (I should note that I limited my analysis to forecasts since 2000. The available data goes back to the mid 1990’s, as I recall.)
NOAA prognosticators consider 0.3 to be pretty good “skill.” In other words, if they can “beat” the EC odds thirty percent of the time, they believe that their forecasts have some usefulness or value. But there are lots of times and places where the weather is just too variable for them to achieve that level of skill in their forecasts.
The other thing that really needs to be hammered home in all of this is that these forecasts are all relative to 1971-2000 normals. There are not really any forecasts here of “specific” temperature levels or trends. That’s where that AP graphic I linked to got it all wrong. IOW, they are not like short term meteorological forecasts that temperatures will be such-and-such.
If anyone is interested, there are specific temperature profiles associated with these forecasts at the climate division level here:
http://www.cpc.noaa.gov/products/predictions/long_range/poe_index.php?lead=1&var=t
Since I live near one of the hot spots in this forecast, I’ve saved one of the detailed forecast profiles (of the Ozark Mountain region) here:
http://www.cpc.noaa.gov/products/predictions/long_range/poe_graph_index.php?lead=1&climdiv=52&var=t
They are projecting a 1.41 degree (warmer) anomaly for this region. I’ll be interested to see how well they do. Everybody around here is stocking up wood like crazy, thinking we are in for the worst winter in a while. And we did tie or break (I haven’t seen official results) the record low last night here locally. Based on their skill in this region, I give them about a 1 in 8 chance of beating an EC forecast. Farmer’s Almanac, anyone?
Northern Plains Reader (21:59:31) :
The one problem with using trends is that CPC better have a good feel about what is causing the trend. If I were to ask CPC as to what the cause of the trend is, I suspect most of the staff would say AGW privately. Publicly, I’m not so sure they want to get into that debate.
I think you are right here (that they think the trends are AGW), but because of the sensitivity of something I’m working on here, I will not go into detail. What is important, what I want to emphasize, is how correct you are that these forecasts are presently being driven primarily by trend analysis, specifically so-called “Optimal Climate Normals.”
I personally think that part of the trend is caused by PDO/AMO oscillations.
Exactly. Because of the flipping of the PDO, we’re now seeing a return a jet stream that sweeps across Canada and then down through the midwest and midsouth regions of the US, bring us colder arctic air more often than we saw during the warm phase of the PDO. Like in the bottom half of the following:
http://science.nasa.gov/headlines/images/elnino/jetstream.gif
It is barely past mid November, and we’ve already had three cold waves bringing subfreezing temperature to my area from this pattern. Assuming it continues, the CPC trend analysis doesn’t stand a chance of getting the forecast right for this coming winter. I think the Old Farmer’s Almanac stands a better chance of being right than the CPC forecast:
http://www.almanac.com/weather/graphs2009/graph.us.8.gif
25deg.F. this Nice clear Eastern Oregon morn.We are supposed to get our first significant snow in LaGrande(Since April) this Thanksgiving…
A month or so ago I posted that the Canada geese that have been wintering in my region of Kansas for the last decade disappeared. They did not bother explaining why they left, or whether they were going north or south, and they left in the night. Earlier this week, they showed back up for one day (enough time to make a serious mess of my sidewalks, I might add) and left again at night – again without saying where they were going.
Now that these forecasts have been made public, it has become clear. The geese read the NOAA and CPC preliminary forecasts for the midwest, and flew up north. During a stay in Minnesota, they picked up a copy of the Farmer’s Almanac, read this more reliable forecast, then quickly ate their fill of fiber and took off for the southlands.
The current NOAA forecast basically ignores this:
http://www.cpc.ncep.noaa.gov/products/people/wwang/cfs_fcst/images/PDFcr_nino34SSTMon.gif
From Basil (20:07:11) :
Then there is the matter of “skill.”… http://i34.tinypic.com/zjasxy.jpg
end quote
Also notice that the only really blue (accurate) areas are down near the desert areas of Arizona et. al. I once saw a quote from a weatherman there that if you just predicted “hot and sunny” every day you would be 95% accurate. Think about it… notice that they are not the bright blue of 95%, but a little below? This implies that their forecasts subtract accuracy from “desert -> hot sunny”…
From pkatt (03:19:57) :… Would ya be able to tell the difference between factory and fire emissions?
end quote
I think so. C isotopes ought to be different from recent trees vs. coal and oil that have ages a few million years. I would expect it to be hard to do, though, unless it isn’t, but maybe it’s about average difficulty. ;=)
This report does not seem to really help my day to day clothing decisions.
I am interested in the comment about the absence of La Nina.
The two most recent ENSO indices according to http://www.cdc.noaa.gov/people/klaus.wolter/MEI/table.html read as -0.569 and -0.739.
Perhaps not quite long enough yet to call La Nina, but it seems as if we are on the precipice of another one.
I was curious, so I put some simple charts together that shows how the index looks as you collapse it into longer averages, and I think it’s rather telling. You can find that at http://digitaldiatribes.wordpress.com/2008/11/21/a-quick-look-at-the-enso-index/ if interested.
I’m intrigued by the wording of the article. So forecasters are “calling for warmer-than-normal temperatures…” A sensible request, it seems, but who (or what) do they expect will respond to their plea? :o)
Will let you all know if it does snow in London (again) over the weekend. One forecast is saying light sleet on Sunday morning. We shall see…
Northern Plains Reader (21:59:31) :
I am trying… just lack the motivation. I am trying to get some snowfall records from various ski hills and then relate them to the ENSO data. The short term delivery system(2 weeks heads up) of fluffy stuff comes at us based on convection and wind, driven by ENSO. Don’t confuse that with all the longer term (PDO) and unpredictable (MJO) parts to kick our but. Personally this winter looks a lot like last years… possibly. The wild card is the arctic. It’s cold, and when it gets cold we can sometimes have a monster low develop over Saskatchewan that could last for a month. That sucks for skiing.
I think Temp and Precipitation are uncoupled systems if traveling from distance.
Basil (16:02:40) :
Joe replied, saying “It is my forecast using the NOAA CDC tool compositing 1961/62, 1964/65 DJF.” So I think he made a new graph from old data that fit his forecast well.
NOAA’s seasonal outlooks aren’t worth the spit to make mud with to sling at such terrible forecasts. IMO
NOAA Claims “NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources”.
However I would be far happier if they claimed “NOAA understands effective Data and Configuration Management techniques, and are able to provide 24 hour public access to both current and archived baselines of your data and any software that has been used to process it in accordance with “.
Why “your data” – because the general public has pid for it’s gathering and storage – and if is being used to motivate policies that impact the lives of the general public. Both in themselves are sufficient reasons for an effective data and configuration management system to be in place.
Ref http://www.climateaudit.org/?p=4395#comments and http://www.climateaudit.org/?p=4414 at Climate Audit discussing the typical data mis-management within the AGW camp.