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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Time for me to hit the shower, get dressed, and go play...Hope you all have a great Sunday!

Back later
Member Since: September 2, 2008 Posts: 93 Comments: 30633
oops...out of coffee...gotta make a store run before MissNadia can respond lol

Yo, pat
How's the kingfish bite on the lake???
Member Since: September 11, 2008 Posts: 9 Comments: 10030
Then you'll have to cruise thru here in the Spring..
We can do it right..

Daugther is a High School Senior ..she can dig in with the Best too.

Beautiful Girls with Happy Smiles there.
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Does this look like faces that would scarf down stacks of Crawfish.......LMAO.....

Member Since: September 2, 2007 Posts: 177 Comments: 20430
Quoting Patrap:
Yeah,,tyvm Tampa...hes bout twice as tall ,that Boy.

He Can eat a whole Sack of Crawfish too...LOL


OH hell yes....i love Crawfish....my kids including the girls would put a place out of business eating Crawfish....some people sqinch at the thought not my southern girls....LOL
Member Since: September 2, 2007 Posts: 177 Comments: 20430
Ditto MissNadia
I'll bow out to "them Carolina yankees" when the temp drops...LOL...Don't send the boys after me ;>)

Member Since: September 11, 2008 Posts: 9 Comments: 10030
Yeah,,tyvm Tampa...hes bout twice as tall ,that Boy.

He Can eat a whole Sack of Crawfish too...LOL
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Quoting TampaSpin:


Ate there many times.......great atmosphere..:)...and the food is dam good also...lol..


Yep, he plays out on the patio, usually afternoon and early evenings. I love places that you can get to by boat...gets pretty congested there sometimes.
Member Since: September 2, 2008 Posts: 93 Comments: 30633
578. Patrap 9:26 AM EST on November 23, 2008
Morning everyone..
Jr and I West-casting on Lake Pontchartrain pre-K.


Pat....those are the things with our children that they will always remember......its amazing the bonding that happens when doing things like that....NOT ENOUGH PARENTS DO THOSE THINGS WITH KIDS.....GREAT PARENTING PAT........not enough of that going around is the problem in this world..
Member Since: September 2, 2007 Posts: 177 Comments: 20430
576 Tampa
You got that right !!!
If you can see the squall line on the horizon, then you've waited too long...lol
Member Since: September 11, 2008 Posts: 9 Comments: 10030
Morning everyone..
Jr and I West-casting on Lake Pontchartrain pre-K.

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Quoting RobDaHood:
TS - will be doing the Tampa/GOM in December. One of my old bandmates is the bass player in the house band at Sheppards on clearwater beach. We've been trying to get together and fish for a couple months but schedules and storms keep interferring...

Vort - hehe, these cold fronts never really hurt much until this year...back, shoulders, elbows...I'm becoming my own barometer. LOL


Ate there many times.......great atmosphere..:)...and the food is dam good also...lol..
Member Since: September 2, 2007 Posts: 177 Comments: 20430
Quoting theshepherd:
562 Tampa
Perfect boat for your area. A fishin' machine.



*****ORCA*****mail****


Its just big enough and Small enough to know you better understand weather and how fast in can turn in the GOM in the Summer months....LOL
Member Since: September 2, 2007 Posts: 177 Comments: 20430
Quoting theshepherd:
Anyone with friends on the kingfish tour?
My nepwhew bailed out of Bilouxi and came home.
6 to 8 foot seas, freezing temps. Most packed up and called it a day.
Tried to get him to drag over to Lake Ponchartrain and look for them there, but he said he's "all done"....

I know two down there. At the end of the first day one was in first and a close neighbor was in fourth. These Carolina men are tough!!!!
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562 Tampa
Perfect boat for your area. A fishin' machine.



*****ORCA*****mail****
Member Since: September 11, 2008 Posts: 9 Comments: 10030
Here is my Daughter on ours......only thing i could find to get the kids to still have fun with dad.......have a 22, 20, girls, and 17yr old son..really hard to find something that everyone enjoyed and the Jet Ski is it...lol

Member Since: September 2, 2007 Posts: 177 Comments: 20430
Anyone with friends on the kingfish tour?
My nepwhew bailed out of Bilouxi and came home.
6 to 8 foot seas, freezing temps. Most packed up and called it a day.
Tried to get him to drag over to Lake Ponchartrain and look for them there, but he said he's "all done"....
Member Since: September 11, 2008 Posts: 9 Comments: 10030
TS - will be doing the Tampa/GOM in December. One of my old bandmates is the bass player in the house band at Sheppards on clearwater beach. We've been trying to get together and fish for a couple months but schedules and storms keep interferring...

Vort - hehe, these cold fronts never really hurt much until this year...back, shoulders, elbows...I'm becoming my own barometer. LOL
Member Since: September 2, 2008 Posts: 93 Comments: 30633
2 weeks ago brother caught a 112lb Drum....OMG was that a fight.......LOL
Member Since: September 2, 2007 Posts: 177 Comments: 20430
Quoting TampaSpin:


Today and Tomorrow.....SW winds in Tampa SWEET Wind for off shore......the GOM will be like GLASS...


Made a mistake i meant SE winds....LOL....sorry....when the wind is out of the SE Florida blocks off the winds....and the lite Southerly breeze is sweet...
Member Since: September 2, 2007 Posts: 177 Comments: 20430
Shep - yeah, the tech advances in modern outboards is amazing, and I agree the limp home factor very important.

TS - good boat for your area...Nice catch ya got there too.
Member Since: September 2, 2008 Posts: 93 Comments: 30633
I like fast, scary...not so much! I've also reached the point in my life that I know I'm not 10ft tall and bullet proof...

Hahaha....I finally figured that out too.
I protested for many years though.
My doctor told me a few years ago to either sell my jet skis or don't bother him anymore!
Argh.
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Quoting RobDaHood:
I like fast, scary...not so much! I've also reached the point in my life that I know I'm not 10ft tall and bullet proof...Winds should be down a few mph today and temps up a few degrees will be more fun, yesterday was pretty choppy on the big lakes.


Today and Tomorrow.....SW winds in Tampa SWEET Wind for off shore......the GOM will be like GLASS...
Member Since: September 2, 2007 Posts: 177 Comments: 20430
I like fast, scary...not so much! I've also reached the point in my life that I know I'm not 10ft tall and bullet proof...Winds should be down a few mph today and temps up a few degrees will be more fun, yesterday was pretty choppy on the big lakes.
Member Since: September 2, 2008 Posts: 93 Comments: 30633
Got a 26Ft Triton now.......much better for the GOM.

Member Since: September 2, 2007 Posts: 177 Comments: 20430
mornon rob
Removed comment, better to take to mail.

New outboards are the ticket. I run Evindude ETEC's on all my boats. Can't beat the "get home safe" system. On synthetic oil they'll run 8 hrs with and oil failure. Engine shuts back to 1250 rpm for any problem. Even if it over heats. Too much heat and they shut off entirely and after it cools you fire her back up and run a bit more. Dealer doesn't want to see them for 3 years for tune up.
Member Since: September 11, 2008 Posts: 9 Comments: 10030
Had a 22ft stratos bass boat with 2 grow men in it would go 85mph .....freaking scary.....
Member Since: September 2, 2007 Posts: 177 Comments: 20430
557. vortfix
HeHe, I had one too and loved it. Ditto the fuel economy thing...ah the good ole days!

You got a makeover (avatar) almost didn't recognize you!
Member Since: September 2, 2008 Posts: 93 Comments: 30633
Morning everyone......here are the latest model run for the GFS for next Sunday as i said a Winter Storm would be........

Here is the GFS..


Member Since: September 2, 2007 Posts: 177 Comments: 20430
I used to have a 16 foot Checkmate with a 135 Merc...back in the 70's.

Most fun boat I've ever owned.
Even with that motor and propped right it made 63mph.
we weren't that concerned about fuel economy back then...LOL

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Morning all!

This is early for me on a Sunday! will give the sun an hour or two to get to work before jumping in the playboats and taking advantage of the dip in fuel prices. One guy I met yesterday has one of the new mercury 150's on a 16 ft checkmate. Runs 65 mph before it gets to squirrely but get this...9 mpg. Had all us big block boys cryin at the gas pumps. I don't think my little jon-boat even gets that kind of fuel economy!

Shep, I was thinking the same thing about Trinidad...Orca needs to talk to Pottery tonite.
Member Since: September 2, 2008 Posts: 93 Comments: 30633
Quoting all4hurricanes:

Hanna hit Haiti hard but I think Dominican dodged some bullets


Just got back from Puerto Plata. Some beaches were severely damaged but most not. There was no major infrastructure damage though considering how they build, is is somewhat hard to tell.
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gm all
Member Since: September 11, 2008 Posts: 9 Comments: 10030
Quoting all4hurricanes:

Hanna hit Haiti hard but I think Dominican dodged some bullets

Yeah. As for vacating down there, they have everything from an inexpensive vacation in a lot of places, to Casa del Campo, in La Romana, which is as elite a place as one can find in the world. :)
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Quoting surfmom:
ipswich -- thanks for the morning's video's -- so lovely to look at, but not a comfortable reality for me!! I wish I could (my body) enjoy it the change.....but being cold just hurts and I get more tired trying to keep my inner furnace going


Its ok.. NO SNOW LEFT )=
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Quoting Orcasystems:
Query, if someone could answer this via WU mail I would appreciate it?

Has anyone been to the Dominican on Vacation.. and if so, where and what did they think? I am looking at going on a last minute vacation down there.. or somewhere warm.

How bad was the Dominican area hurt by the Hurricanes this year?I know they were hit by few of the TD's.

Hanna hit Haiti hard but I think Dominican dodged some bullets
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video is a hoot ! Spouse just woke.... got to pour him coffee & get out running --gather up Dave the Cat & take a Nap!! Sleep is important -- specially w/school and all..... See you later Cot : )
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Quoting surfmom:
Cot -- do YOU sleep? What time on your island


...Link

:)

Though seriously, yeah, just haven't being sleeping too well lately.

It's just past midday here.
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Cot -- do YOU sleep? What time on your island
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Chickens are causing making all kinds of noises this morning -- they handle the cool weather (cold) better then me -- though they do go through feed far more quickly.

Polo horses are thriving in this weather. I love their woolly winter coats & well most people clip for the look, because the herd we care for is outside 24/7 they keep their coats. It's such a great feeling to warm your hands on their bodies after they've warmed up from a work out
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Amazing, it's reached low 40s here...
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ipswich -- thanks for the morning's video's -- so lovely to look at, but not a comfortable reality for me!! I wish I could (my body) enjoy it the change.....but being cold just hurts and I get more tired trying to keep my inner furnace going
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Good Morning, Sipping some coffee, enjoying my quiet sleeping house, and getting ready to face the cold (I know this is relative) for a Sunday morning run
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Good Morning All... Its been Snowing in England.. and I have 2 movies of the snow... So here you go:




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Widespread heavy snow warnings in place here...

Already some here this morning. Though, it's bucketing sleet right now.
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Brisbane Storm images Link
Story on the worst hit street in Brisbane Link
Cheers AussieStorm
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Quoting Stormchaser2007:


They were hit by Gustav-(90mph) Hanna-(outer rain bands) Kyle-(Heavy flooding) and Fay-(40mph)....I dont know if they repaired most of the damage.


Its really hard to find some place to go on such short notice. A lot of Mexico is already booked.
Member Since: October 1, 2007 Posts: 81 Comments: 26493
Quoting Orcasystems:
Query, if someone could answer this via WU mail I would appreciate it?

Has anyone been to the Dominican on Vacation.. and if so, where and what did they think? I am looking at going on a last minute vacation down there.. or somewhere warm.

How bad was the Dominican area hurt by the Hurricanes this year?I know they were hit by few of the TD's.


They were hit by Gustav-(90mph) Hanna-(outer rain bands) Kyle-(Heavy flooding) and Fay-(40mph)....I dont know if they repaired most of the damage.
Member Since: Posts: Comments:
Query, if someone could answer this via WU mail I would appreciate it?

Has anyone been to the Dominican on Vacation.. and if so, where and what did they think? I am looking at going on a last minute vacation down there.. or somewhere warm.

How bad was the Dominican area hurt by the Hurricanes this year?I know they were hit by few of the TD's.
Member Since: October 1, 2007 Posts: 81 Comments: 26493

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About JeffMasters

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