Winter forecast, part II: NOAA's predicts a warm winter for the Central U.S.

By: Dr. Jeff Masters , 2:51 PM GMT on November 21, 2008

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Let's follow up on yesterday's discussion about the long range forecast for the coming United States winter. Those of you outside the U.S. will probably be more interested in what the International Research Institute for Climate Prediction has to say for your country, and I encourage you to check out their excellent web site for their seasonal forecasts.

The official National Oceanic and Atmospheric Administration (NOAA) 90-day forecast for the upcoming winter, issued on November 20 by their Climate Prediction Center (CPC), calls for above average temperatures across the Central U.S. and Alaska. The remainder of the country has equal chances of above or below average temperatures. A dryer than average winter is expected over much of the Southern U.S., including the drought-stricken Southeast U.S.


Figure 1. Temperature forecast for the upcoming winter--December, January, and February 2009--made by NOAA's Climate Prediction Center. No areas of the country ar forecast to have an above-average chance of being colder than normal, but the Central U.S. has up to a 50% chance of having above-average temperatures.

How are the NOAA winter forecasts made?
NOAA uses several tools to make their forecasts. One key tool is their Climate Forecast System (CFS) model. This model includes a version of the GFS forecast model that we use for everyday weather and hurricane track forecasts. The CFS model also includes an ocean model that interacts with the atmospheric model. These models solve mathematical equations of fluid flow using a supercomputer for the entire globe, on a 100-km grid. NOAA also uses statistical models, which look at past winters and see how they depended on quantities such as sea surface temperature anomalies. Temperature trends are important, too--if it has been warmer than average the last ten years, it's a good idea to forecast a warmer than average winter.


Figure 2. Skill of the official 90-day forecasts issued 0.5 months in advance by NOAA's Climate Prediction Center. Note that the average skill over the past ten years is not very high (9 on a scale of 0 to 100), and has remained flat, indicating that our skill in making long-range forecasts has not improved.

How good are the NOAA winter forecasts?
NOAA rates its forecasts using the Heidke skill score, which is a measure of how well a forecast did relative to a randomly selected forecast. A score of 0 means that the forecast did no better than what would be expected by chance. A score of 100 depicts a "perfect" forecast, and a score of -50 depicts the "worst possible" forecast. For 90-day temperature forecasts issued 0.5 months in advance, NOAA has averaged a 9 out of 100 on the Heidke scale since 1995 (Figure 2). So, while there is some skill in forecasting what winter temperatures will be like, this skill is not much better than flipping a coin. Depressingly, Heidke skill scores for three-month precipitation forecasts are even worse, averaging just a one on a scale of 1 to 100 over the past 15 years.

Let's look at some examples. Last's year's winter temperature forecast issued in mid-November did poorly (Figure 3), failing to forecast that the U.S. would have equal areas with both above and below average temperatures. The 90-day forecast done in mid-November of 2005 for the winter of 2005-2006 was awesome, with a Heidke skill score of 45. However, the 90-day forecast done in mid-November of 2006 for the winter of 2006-2007 had virtually no skill, with a Heidke skill score of one.



Figure 3. Temperature forecast for Dec 2007-Feb 2008 issued by NOAA's Climate Prediction Center on November 15, 2007 (top). They predicted Equal Chances (EC) of either above or below-average temperatures for the Northwestern U.S. (white colored areas), and a 30-60% chance of above average temperatures over most of the remainder of the country. In reality, the U.S. experienced an average winter, with approximately equal areas of the country receiving above and below average temperatures (bottom). Image credit: National Climatic Data Center.

Why do seasonal forecasts do so poorly? Primarily, it's because the long-term weather patterns are chaotic and fundamentally unpredictable. To a lesser degree, we are limited by our imperfect physical understanding of what controls the climate, and our imperfect computer models we use to simulate the climate. As computer power continues to increase and our models include better representations of the weather and climate at finer grid sizes, I anticipate that seasonal forecasts will improve. However, given that long-range forecasts have not improved since 1995 despite a large increase in computer power, I doubt that this improvement will be more than 10-20% over the next thirty years.

Seasonal forecast models vs. climate models
A common complaint one hears about global warming predictions made by climate models is, "How can we trust the predictions of these climate modes, when they so such a lousy job with seasonal forecasts?" It's a good question, and there is no doubt that seasonal forecasts have pretty marginal skill. However, there is a fundamental difference between making a seasonal forecast and making a 100-year climate forecast. A seasonal or a short-term weather forecast is what mathematicians call an "initial value" problem. One starts with a set of initial meteorological and oceanographic values that specify the initial state of the planet's weather, then solve the equations of fluid flow to arrive at the state of the atmosphere a few days, weeks, or months into the future. This forecast is highly sensitive to any imperfections one has in the initial conditions. Since there are large regions of the atmosphere and ocean we don't sample, it's guaranteed that the prediction will suffer significantly from imperfect initial conditions. Furthermore, the chaotic and turbulent nature of the atmosphere leads to many "bumps" in the weather pattern over time scales of days, weeks, and months. The nature of turbulence makes it impossible to accurately forecast these "bumps" that are superimposed on the mean state of the climate.

A 100-year climate forecast, on the other hand, is what mathematicians call a "boundary value" problem. Given an initial and final set of factors (called "forcings") that influence the climate, one runs a climate model 100 years into the future. The final state of the climate will depend on the strength of the forcings supplied. This type of model is not very sensitive to initial conditions, and is not trying to forecast the "bumps" of chaotic, turbulent atmospheric motion superimposed on the mean climate. Rather, one is trying to forecast the mean climate. As computer power increases and our physical understanding of how the climate works grows, these type of models will continue to significantly improve. While climate models do fail to properly simulate important aspects of our past climate, such as the Arctic warming of the 1930s, and the observed 0.1°C global temperature increase that occurs at the peak of the 11-year solar sunspot cycle, they have been very successful at simulating things like the global cooling triggered by the 1992 Mt. Pinatubo eruption, and the observed pattern of greatest global warming in the Arctic. I believe that climate models are already significantly more reliable than seasonal forecast models, and should continue to improve steadily in coming years.

Support the Portlight Christmas for Gulf Coast Kids Honor Walk
Saturday is the portlight.org Christmas for Gulf Coast Kids Honor Walk. This is a fundraiser to buy gifts for the kids along the Gulf Coast who might not have much in their stockings this year because of the ravages of Hurricane Ike. Our own StormJunkie will be walking up the Arthur Ravenel Jr. Bridge in Charleston, SC, and will be taking his webcam along. Tune in to the webcam site at 2:30 pm EST to follow the walk, and participate in a live chat. Sponsorships of any amount, small or large, are appreciated! The cam will go active about an hour before the walk. It should be a cold but beautiful day.

Jeff Masters

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Member Since: Posts: Comments:
Quoting MichaelSTL:
Come on, when are you going to fold? You can't win, I have debunked every piece of misinformation and lies that you have posted so far.


I am a conspiracy theorist to the end. Only time will tell. My bet is we are not causing “climate change.” Scientific theory is only as good as the mathematical formulas devised to produce the intended results. And that is what they are looking for. So that is what they will find.

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all I know is that our pollution has an effect on the earth but no "Day after Tommorrow" type of scenario

PS I gotta show everyone something that happened last night if you weren't up

brb to upload a photo
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Catch you later...men are appearing...point to bellies.......
Member Since: July 18, 2007 Posts: 30 Comments: 26536
Taz -- bearer of ...News 96L never would have believed it...but I kept my mouth shut so I don't have to eat crow this time
Member Since: July 18, 2007 Posts: 30 Comments: 26536
well lets see theres......


INVEST 96L!!!!!!!!!!!!!!!

LOL sorry had to do it!
Member Since: Posts: Comments:
I have not the scientific background, or savvy to discuss GW -- but I feel that until we do know for sure.... why would we do anything that could be contributing to a situation that is not healthy for the planet earth.

Telsa did some very fascinating work in regards to energy(although there is much in regards to weapons I find horrifying)
Member Since: July 18, 2007 Posts: 30 Comments: 26536
Quoting MichaelSTL:
How significant are human impacts?

They say that you can't see anything man-made from space, but this shows otherwise:



Of note is that aerosols only remain in the atmosphere for days, so you need a large constant output to maintain high levels, unlike greenhouse gasses which will accumulate due to much longer lifespans, even the shorter-lived ones like methane, which still has about 20 times the warming potential of CO2 over a century despite having a residence time of only 10 years (note that this can be misleading; it doesn't just all vanish in 10 years but rather more like radioactive half-life where half lasts 10 years, 1/4 20 years, etc). On very long time scales (irreverent to the present), levels of greenhouse gasses, mostly CO2, vary due to geologic processes, along with global temperatures (levels of CO2 have been gradually declining since Earth formed, while temperatures have remained relatively constant, excluding swings (largely caused by continental drift; e.g. Antarctica drifting towards the South Pole and becoming isolated caused a big drop), because of long-term solar brightening).

Perhaps of greatest concern is what happened in the past when sudden jumps in greenhouse gasses occurred; e.g -

Paleocene–Eocene Thermal Maximum

The event saw global temperatures rise by around 6 °C over 20,000 years, with a corresponding rise in sea level as the whole of the oceans warmed.[2] Atmospheric carbon dioxide (CO2) concentrations rose, causing a shallowing of the lysocline. Regional deep water anoxia may have played a part in marine extinctions. The event is linked to a negative excursion in the δ13C isotope record, which occurs in two short (~1,000 year) pulses. These probably represent degassing of clathrates ("methane ice" deposits), which accentuated a pre-existing warming trend. The release of these clathrates, and ultimately the event itself, may have been triggered by a range of causes. Evidence currently seems to favour an increase in volcanic activity as the main perpetrator.


(recent findings have added to concerns that large amounts of methane could be released; of course, the warming from that, if it happens, could be considered "natural", but not the warming that lead to it)


True, the location of continents has a large impact on the Earths climate. The location of continents affects the oceanic currents which distribute thermal energy.
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I don't know about "Global", but it has been below freezing every night for a week here in N. Ga. 16 last night. 1" of ice across my 1/2 acre pond. Spring feed & 15' deep.
Not even Thanksgiving yet!
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we now have 96L



WHXX01 KWBC 232110
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2110 UTC SUN NOV 23 2008

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

DISTURBANCE INVEST (AL962008) 20081123 1800 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
081123 1800 081124 0600 081124 1800 081125 0600

LAT LON LAT LON LAT LON LAT LON
BAMS 9.9N 80.1W 9.6N 82.7W 9.5N 85.0W 9.4N 87.0W
BAMD 9.9N 80.1W 10.2N 81.8W 10.6N 83.4W 11.1N 84.9W
BAMM 9.9N 80.1W 10.1N 82.0W 10.4N 83.8W 10.6N 85.4W
LBAR 9.9N 80.1W 10.1N 80.6W 10.5N 81.4W 11.0N 82.1W
SHIP 30KTS 35KTS 38KTS 39KTS
DSHP 30KTS 35KTS 32KTS 29KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
081125 1800 081126 1800 081127 1800 081128 1800

LAT LON LAT LON LAT LON LAT LON
BAMS 8.9N 88.6W 8.0N 91.8W 7.6N 94.7W 7.3N 97.5W
BAMD 11.4N 85.9W 11.0N 87.2W 10.6N 89.2W 10.1N 91.8W
BAMM 10.4N 86.6W 9.4N 88.7W 8.9N 91.0W 8.0N 93.4W
LBAR 11.6N 82.2W 13.2N 81.2W 15.9N 77.8W 19.9N 72.3W
SHIP 40KTS 31KTS 15KTS 0KTS
DSHP 32KTS 23KTS 0KTS 0KTS

...INITIAL CONDITIONS...
LATCUR = 9.9N LONCUR = 80.1W DIRCUR = 90DEG SPDCUR = 1KT
LATM12 = 10.2N LONM12 = 80.5W DIRM12 = 158DEG SPDM12 = 3KT
LATM24 = 10.7N LONM24 = 80.4W
WNDCUR = 30KT RMAXWD = 60NM WNDM12 = 30KT
CENPRS = 1007MB OUTPRS = 1012MB OUTRAD = 200NM SDEPTH = D
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM
Member Since: Posts: Comments:
Quoting theshepherd:
Uh oh mom
Capt Sparrow is on the tube...


Shepherd... ahhh thanks- RUNNING TO TV IN SEARCH OF THE CLICKER....a few days ago, I showed my spouse a picture of Captn' Jack Sparrow ...spouse says "I don't look like him"... I replied laughing "OH YES YOU DO!!"
Member Since: July 18, 2007 Posts: 30 Comments: 26536
Quoting theshepherd:
Yo, mom
Been fishin' lately.
Waiting to see if you improved on my mango/plum salsa ???


No Time -- just a few minutes to catch my breath. Polo season has arrived, and now my work goes into full gear. All the families have just about returned, the barns are almost all filled up. From a ghost town to a vibrant horse filled athletic facility. Training and more training,(horses, young buck) games & practices, cleaning of tack, grooming -- very little time to be near my ocean -- or snitch away to surf. Plus physically I get beat. The work is labor -- I love it mind you -- but it tires me
Member Since: July 18, 2007 Posts: 30 Comments: 26536
"Data discovered on NASA's Goddard Institute for Space Studies (GISS) website revises recorded temperatures for the United States. It is expected that similar revisions will also be made for global temperature recordings. This information was discovered by Steve McIntyre of Climate Audit on Wednesday (8/8/2007). No NASA press release, no James Hansen (head of GISS) announcement, nothing. Could it be because they don't want anyone to see it? The data is certainly devastating for the Al Gore camp which has based much of their Carbon Credits sales pitch on recent temperatures (e.g. claiming that 1998 was the warmest on record)."
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Uh oh mom
Capt Sparrow is on the tube...
Member Since: September 11, 2008 Posts: 9 Comments: 10165
Yo, mom
Been fishin' lately.
Waiting to see if you improved on my mango/plum salsa ???
Member Since: September 11, 2008 Posts: 9 Comments: 10165
T.C.F.A
EST POS
11.4N/79.9W
DEV SLOW TO OCCUR
PRECIP 200+MM
FLOODING RISK HIGH
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Quoting Skyepony:
My father showed me a hydrogen powered remote control car, all excited & followed with this story. When he was a teen, a friend had run across a 1920 something ford that was electric & ran on hydrogen. It had a thing to distill water & a hydrogen still to make hydrogen from water. They spent a few weeks rewiring it & fixing it up. Ran beautifully & for free... When cars were 1st introduced they weren't just gas. People prefured electric. Ford & the rest didn't give it to us then or since. If we have to bail them out, I want to be able to plug my next car into a solar panel or my hydrogen still, not pay another country so I can drive it..

The serria club article sounds like pro oil propaganda to me.
Knowing a bit about exotic animals myself, you should take anything the Sierra Club publishes with a grain of salt.
Electric cars are no problem, it's the battery thingy that needs work. lol
Some interesting hydrogen generators on ebay. Their shortcomings are evident.
Member Since: September 11, 2008 Posts: 9 Comments: 10165
He is going to PR -- not me ; (
Member Since: July 18, 2007 Posts: 30 Comments: 26536
MichaelSTL - tapped a note to my surf weather buddy - asking him about the relationship of La Nina & El Nino in relationship to surfing -- (he also liked the link you gave me) I thought you'd enjoy.

"a moderately strong el nio is better for winter, la nia is better for cape verde hurricanes in lat aug &september

el nio's bring low presure to low lattitudes so we get lows in the gulf which can make for epic days 4-6ft and glassy

gotta go, packin for PR"

Member Since: July 18, 2007 Posts: 30 Comments: 26536
662. Skyepony (Mod)
My father showed me a hydrogen powered remote control car, all excited & followed with this story. When he was a teen, a friend had run across a 1920 something ford that was electric & ran on hydrogen. It had a thing to distill water & a hydrogen still to make hydrogen from water. They spent a few weeks rewiring it & fixing it up. Ran beautifully & for free... When cars were 1st introduced they weren't just gas. People prefured electric. Ford & the rest didn't give it to us then or since. If we have to bail them out, I want to be able to plug my next car into a solar panel or my hydrogen still, not pay another country so I can drive it..

The serria club article sounds like pro oil propaganda to me.
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661. IKE
Quoting sporteguy03:


Should be watching football Ike.:)


I am....
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Quoting IKE:


Exactly.

Fortunately I have to go to town and will miss out on the rest of the arguing over it.



Should be watching football Ike.:)
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Quoting Drakoen:


It's always the same...


Which is why it has been added to my do not discuss list, along with politics and religion. ...oh yea, and hurricane forecasting :)
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A funny artical from the past


Link
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Link
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656. IKE
Quoting Drakoen:


It's always the same...


Exactly.

Fortunately I have to go to town and will miss out on the rest of the arguing over it.

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Link
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Quoting IKE:
Global warming debate***yawn***


It's always the same...
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653. IKE
Global warming debate***yawn***
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Aw, shucks, I gotta go. I haven't dipped into the GW debate for a while, and I was just getting my feet wet. . . .
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Quoting vortfix:
Hostile Green Takeover: The Auto Industry Faces Environmental Thuggery

Senate Floor Speech - November 20, 2008


Senator James Inhofe (R-OK) Ranking Member, Environment and Public Works Committee



The latest bailout demand making the rounds in Washington is for the Big Three auto industry. Democrats would have you believe the proposed bailout is all about saving jobs, but, having been in Washington long enough, my instincts led me to dig deeper where I unearthed green roots hiding beneath the bailout rhetoric.

The proposed $25 billion bailout of Detroit now appears to have been hijacked by the powerful environmental lobby.

I only want to comment that the $25 billion u are talking about is actually money that has been set aside for "green" automotive development in the first place. Can't hijack it for the greening process if it's already been put aside for the greening process. . .

Also, I really think Congress SHOULD demand auto industries look for ways to develop non-oil dependent technologies ASAP. America has lost a lot of its clout worldwide because it is so dependent on non-American energy. From my viewpoint, saving the auto industry is much less about the environmental concerns (though I believe strongly that these concerns matter) and a lot more about saving America from massive international debt and dependence.
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Quoting 15hurricanes:
The period 1995-2008 has been the most active for Atlantic hurricanes in the historical record.

2009 ??? Wait and see what happened!

hahahaha!!
The scary part about this is there is no way of knowing for sure if this so-called "active" period is actually closer to the norm, while the relatively inactive period seen in much of the 20th century was the anomaly . . .

Part of my concern about global warming predictions (regardless of whether they are actually reflecting the reality) is that our database on warming and cooling trends is so minute. Additionally, by the time we have gathered enough data, whatever trend or lack thereof will have played itself out . . .

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Thank you STL 642
someone needed to say it
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Quoting vortfix:



Pelosi was on TV this morning touting the new increased offer of 75 Billion to be made to the auto companies this upcoming week.
It's pretty obvious they want to get a shoe in that auto door and hope to push other agendas down their throats by doing so.
As much as I hate to see what is about to happen to the employees, retirees and children of auto workers...I feel bankruptcy is the best alternative.


Pelosi,Melosi. She's a bane on society.
I'm almost with you on bankruptcy, but I think the opportunity to pick them back up and stand them on their feet needs a good think. If the pursuit of efficient developement and the elimination of the UAW were the guiding premises, I would support a helping hand.
Member Since: September 11, 2008 Posts: 9 Comments: 10165
Quoting whatwhat1:
Another good link on Co2.


Link

So much for a review of high school freshman biology.
Member Since: September 11, 2008 Posts: 9 Comments: 10165
640 vort
The article doesn't mention that GM and Ford have reinvested $476 billion of their own money back into operations since 1997. What's another 25 going to accomplish???
It's way past time the UAW died it's long deserved death. With a wage scale 3 times the national average and living in a state with a zero economy, my sympathy goes out only to the children and retirees missled with a golden parachute retirement dream. The money should go for a union free reorganization and product reassesment. The less fortunate retirees need a hand for sure.
Just my two cents...lol
Member Since: September 11, 2008 Posts: 9 Comments: 10165
15Hurricanes, using the term "historical record" is meaningless. You mean since Hurricane records have been kept? - ie: a nanosecond in the greater picture? It is impossible to predict on such a slither of time and evidence - even if the green lobby will fool you into belivieving a few years worth of dubious data justify their doom theory.
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630
There are also them "what teach" and them "what do".
Member Since: September 11, 2008 Posts: 9 Comments: 10165

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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