August 30th, 2011
11:23 AM ET

How Irene's forecast missed the mark and why it could happen again

They know they missed it. Forecasters at the National Hurricane Center in Miami say when it comes to the strength of Hurricane Irene as it approached North Carolina, they know they were off. Way off.

“At least in the guidance we were looking at there was no indication of anything that would cause the storm to weaken. So, we thought we would have a Category 3 at landfall,” said Bill Read, the director of the Hurricane Center. Irene came in at a Category 1, the weakest. Read said there’s good reason they were so far off.

The science of forecasting how strong or weak a storm will become is simply not very good. With Irene, forecasters say they weren’t even as good as their five-year average.

“Every storm comes up with a surprise,” Read said. “In this case it was one where it went downhill. Charlie a few years ago is one that went uphill. Neither case did we see that coming, and that’s my measure of the fact that we have a long way to go.”

Bill Read, of the National Hurricane Center, talks about the difficulty of predicting hurricanes.

Hurricane forecasters say they want to get it right all the time. But if you are going to be wrong, they say it's better to be wrong in weakening storms like Irene.

“I’d say a bigger worry than one weakening at landfall is the ’35 hurricane that came through the Keys," Read said. "Charlie if it’s a little bigger. Audrey in 1957. Get the picture?”

In all of these cases, the storms rapidly intensified as they neared the coastline. By then, it’s too late to order massive evacuations.

CNN's severe weather expert Chad Meyers said when Hurricane Irene smashed into the Outer Banks of North Carolina, the contact weakened the storm.

So, forecasters had the path right, but the impact of landfall changed what the amount of destruction would be in some areas. Wind shear helped knock down velocity, and unexpected dry air sucked some of the power out of the storm.

"It literally knocked the stuffing out of the eye," Myers said. "It never got its mojo back."

Meteorologists measured pressure levels inside the storm that could have allowed it to strengthen back into a Category 3 hurricane, Myers said, but Irene's romp over land in North Carolina prevented the eye wall from spinning into a more destructive storm by the time it arrived in New York.

"It never had that opportunity because North Carolina got in the way, dry air came across over Virginia and Maryland and got in the way, and although this was very low pressure, the reason why we could never let the guard down for New York City ... was because the pressure was low enough that at any time, if this storm decided to get its act together, it could have gone from a 60-70-80 miles per hour storm - it easily could have been a 110 (miles per hour) storm like it was in the Caribbean and like it was in the Bahamas."

Add to that the difficulties of having true accurate model data when it comes to hurricane forecasts.

“Real-time observations, like that collected by NOAA’s Hurricane Hunters, are put into these models to hopefully give a more accurate forecast. We are much more accurate on forecasting severe storms and their behavior for this very reason, the availability of observations," CNN meteorologist and weather producer Sarah Dillingham said. "These storms occur over land, allowing scientists to take measurements within those storms and use that data to run computer models. Think about a hurricane, over water, with no way to collect data except from above.

"Makes it difficult to see what is actually going on, right?"

Dillingham said dropsondes, instruments that are dropped from above and into these storms, are used to collect data inside hurricanes as they fall to the surface.

"This is helpful, but you are also trying to view the data it collected, track where it was in the storm, and at the same time determine what that means from a scientific perspective," she said. "Also, you may think, what about trying to send something up into the storm from below. In a hurricane? Good luck with that."

Dillingham said "the sparsity of real-time observations in tropical systems is what makes it so difficult to produce a more correct intensity forecast, and certainly makes it difficult to improve them."

"The track of these storms depends on atmospheric winds and surrounding storm systems, and we understand these factors much better, giving us a better handle on the 'steering' of these systems," she said. "This makes tracking more accurate overall. Things like RI, or rapid intensification, in tropical cyclones is just not fully understood yet, and until we can obtain that vital observational data within these storms - while they are over open, warm waters - we will struggle to model these kinds of processes.”

For that reason, Dillingham said Read's explanation of why they have trouble making these predictions is spot on.

And that's also why Read says the decisions to evacuate made by emergency managers and state and federal officials was the right one.

In every aspect of the storm except for wind speed, Read says, they got it right.

According to their initial analysis, the track forecast of the storm was 20% better than their five-year average. They do very well at predicting the path of a hurricane.

“We had storm surge flooding all the way up from the Carolinas into New England," Read said. We’ve had tremendous and tragic rainfall flooding. We’ve had loss of life from trees down well inland and the power outages.”

Hurricane forecasters admit their ability to foresee a storm’s strength is not much more today than it was 20 or 30 years ago.

According to the Hurricane Center’s initial analysis, “Irene exemplifies the state of the science.” They are pinning their future hopes on programs like the Hurricane Forecast Improvement Project. Scientists say they are seeing some promising results. This program uses high-resolution models and enhanced Doppler radars to measure the core of Hurricanes.

Forecasters say that three out of four times you will likely be asked to evacuate and you’ll coming back saying "Why did I leave?"

But that fourth time, if you don’t, Read says, you’ll wish you had.

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Filed under: Flooding • Hurricane Irene • Hurricanes • Weather
soundoff (639 Responses)
  1. Jim

    I think the news is more "upset" about the weak storm than the people who are getting home and saying "thank God they were wrong". In a culture of 24/7 news coverage, a natural disaster is ratings gold. Had Irene been a category 3 and caused wide-spread damage, it would have given CNN and other channels something to fill the air for a few weeks.

    They did the same thing with the earthquake that hit the East coast. I was watching CNN soon after it happened and they were just searching like crazy for SOMETHING to be broken. In every interview the fear-mongering was rampant as the anchor asked about the completely undamage nuclear power plant in a way that made it sound like half the coat would be glowing for the next 200 years.

    August 30, 2011 at 1:49 pm | Report abuse |
    • vmaxnc

      Should we be thanking god for the 28 people who died? Are the families of those people thanking god for the outcome of the storm?

      August 30, 2011 at 2:00 pm | Report abuse |
    • Feast of Beast

      Good point. The media IS a bunch of bloodhounds waiting for a fresh kill to report. Surprising that they didn't threaten one of their field reporters with the loss of his job if he didn't throw himself over a seawall for dramatic action once the wind was over 20 mph. Reminds me of the Glenn Frey song "Dirty Laundry", an accurate description of media hype and apathy.

      August 30, 2011 at 2:02 pm | Report abuse |
  2. byron henry

    Remember, we are not God and will never be able to pinpoint the exact strength of a storm. In Nahum 1:3, the Bible states that "The LORD is slow to anger, and great in power, and will not at all acquit the wicked: the LORD hath his way in the whirlwind and in the storm, and the clouds are the dust of his feet".

    Basically, please let God do HIS job and trust in HIM. Maybe through your prayers and good relationship with HIM, the storm might be a blessing to everyone. It seems this is the time when everyone gets "scared" and focused on what they are supposed to be doing right in life.

    I hate that lives were lost including a rescuer, but it seems like the world pays attention when airplane flight cancellations, major events cancellations, and TV warnings from politicians prompt action. If you noticed, no one ever came on the news talking about President Obama or anything else negative. The President is doing an outstanding job even though some people criticize him for everything? I wonder why people criticize him even when they are not the PTA president, or even the president of the local football league, or local college. Doesn't it take more than that to be the President of the United States?

    Anyways, how the tide can turn in a couple of days? Interesting!

    August 30, 2011 at 1:50 pm | Report abuse |
    • vmaxnc

      Should we be thanking god for the 28 people who died? Are the families of those people thanking god for the outcome of the storm?

      Yes, it's the same post as above. It fits just as well here. I'm sure the families of the dead are thanking Him In All His Wisdom For Allowing Their Family To Die.

      August 30, 2011 at 2:04 pm | Report abuse |
    • W. Ellington

      vmacnc, its called freewill. They where were they were at there own freewill. It is not for us to judge why they died or to blame God, only to feel there loss and greeve for the families of the lost. Do not ever try and second guess his will. He even said it was not his wish that any of us should perish, but we brought it upon ourselves for our own greed.

      August 30, 2011 at 3:23 pm | Report abuse |
    • byron henry

      Like Wellington stated, we are "pottery" and we should not be trying to figure out the "Potter's" reason for what has been done or made. Do we question the bank teller after we make a deposit to make sure the money is there or do we call the DOT (Department of Transporation) for every bridge that we drive over, or do we question the manufacturer of a cheap TV about defects? Well, I think that we don't. So why do we always question God?

      August 30, 2011 at 3:49 pm | Report abuse |
  3. Jueceman

    Its a storm. it alows us to strengthen our power grids and draining systems or roads when thing go array. Maybe people should get trees inspected around the house more often. Maybe cities should invest in underground infrastructure on the east coast. Well kept trees actually sheild underlying things from storms, so maybe should plant more trees. These things raise ideas that normally wouldn't be thought of. Its better to be proactive. But predicting the weather precisely has to be one of the most riduclous things I've ever heeard of. People actually are going to have to evacuate certain areas every year in Hurricane season??? C'mon, how about if you're at risk for hurricanes it is mandated that where you live is hurricane proof. Steel beam housing???? Advance draining systems???? Where are the engineers??? Who's thinking in America??????

    August 30, 2011 at 1:51 pm | Report abuse |
  4. cp

    What an idiotic headline! Just ask people in North Carolina, New Jersey & Vermont if the mark was missed.

    August 30, 2011 at 1:51 pm | Report abuse |
  5. kurtinco

    This story makes the wrong assessment. Yes, wind speeds were over-estimated. But Irene was never about wind. It was about rain and storm surge, and the estimates there where on the money. And it could have easily been far worse. I heard it described well the other night on The Newshour on PBS. Imagine an ice skater with her arms stretched out twirling in a stationary circle. As she brings her arms in, she spins faster and faster and faster. A hurricane is much the same way. In this case, by the time it reached New Jersey, the storms arms had spread out, slowing the spin of the storm. The storm's arms could have easily retracted, intensifying it's spin and then this story would never have existed. I for one appreciated the early warnings and the time to prepare.

    August 30, 2011 at 1:52 pm | Report abuse |
  6. Logic

    What's a few dozen miles per hour (sustained winds) among friends? I don't think the people who lost property or loved ones care one bit. It's a hurricane, they got the path right. Ok I am ready for 100 mph winds, oh only 75? Lucky me...

    August 30, 2011 at 1:53 pm | Report abuse |
  7. Mary

    CNN are the ones way off the mark on this story! The storm went exactly where the Weather Channel said it was going and at very close to the intensity they predicted. What in heck are you talking about? Did any of your people ever take ANY science classes?

    August 30, 2011 at 1:53 pm | Report abuse |
  8. American Man

    Blah blah blah. I'm so sick of the blame game. The Boy Scout Motto holds true even today: BE PREPARED.

    So what if they got it wrong? So what if the hurricane wasn't as bad as it could have been? Would people really want the burden on their shoulders if they instead said: "Ah, ignore it, it won't be that bad," and thousands died? It is better to be safe than sorry when things such as this occur.

    August 30, 2011 at 1:53 pm | Report abuse |
  9. Dale

    Even hurricanes these days are becoming political and choked with government bureaucrats trying to score points, and the press and the media took it hook line and sinker suckers.

    August 30, 2011 at 1:54 pm | Report abuse |
    • Dale

      One other thing today's meteorologist on CNN and Fox and all the others do they ever look at the vapor loops the moment I saw this hurricane sucking in all this dry air I knew it was, die quickly.

      Today meteorologist are clueless the only thing they're looking for is a headline talking head story.

      August 30, 2011 at 1:59 pm | Report abuse |
    • Old-Skool Conservative

      Speak for yourself Dale! If Obama hadn't tried to ram socialized weather down our throats, then free-weather principles would have prevailed, and... ...and... ...oh, errr, ummmm.... nevermind.

      August 30, 2011 at 2:01 pm | Report abuse |
  10. whattheheckdidyouwant

    Tell the families of the two dozen dead that it was a feeble, insignificant storm. Tell that to the people who lost their homes and didn't think they would ever need flood insurance. CNN is just mad that they don't have a captivating story of horrific destruction and thousands dead or dying so they can get some nice big ratings. Sorry it's not as hideous and gruesome as you were hoping for.

    August 30, 2011 at 1:54 pm | Report abuse |
  11. Robert

    OK, now for those idiots who refused to evacate and now need help let THEM pay for it. If people did not have an IQ of i/2 there would be less expense and less death. Why do people ignor forecasts?

    August 30, 2011 at 1:54 pm | Report abuse |
  12. Ryan

    They mean "Charley" the hurricane that slammed FL as a cat 4

    August 30, 2011 at 1:55 pm | Report abuse |
  13. Maxxron

    What's sad is a category 1 creating the amount of havoc that it did on this supposed "first world" nation.

    August 30, 2011 at 1:55 pm | Report abuse |
  14. Luis

    This is mother nature how can we expect to "predict" what she will do. I live in South Florida and they are pretty much on the money when it comes to the time the storm will hit and where the storm will hit. You cant ask for more than that.

    August 30, 2011 at 1:55 pm | Report abuse |
  15. Times

    Hurricane Katina is coming with possible round 2 for everyone again and though I hope it would not be true. We'll have to wait and see.

    August 30, 2011 at 1:56 pm | Report abuse |
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