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.

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

    Of course they are never going to get it right, this is nature we are talking about...unpredictable, can change on a dime weather. Forecasters are not God.

    August 30, 2011 at 4:21 pm | Report abuse |
  2. a disgrace

    the press was so hysterical trying to get ratings that blew a summer rain storm into the storm of the century!

    August 30, 2011 at 4:25 pm | Report abuse |
    • Robin

      You certainly are a disgrace for feeling that way. Haven't you ever heard the expression, "Better safe than sorry"? You are acting like the mayor of Amity in "JAWS" that wants folks to swim in the shark-infested ocean.
      Next time there's a hurricane headed your way, sign a waiver that you take responsibility for your own safety and that you won't claim any insurance money for damages occurred and sit it out. Until then, just shut up.

      August 30, 2011 at 4:35 pm | Report abuse |
    • mdubbs

      NYC is not the center of the universe.. It's far from being that important. For your sake, I hope the next storm coming is "just a summer rainstorm" as well. Or maybe you'll all get the direct hit you were apparently all so hoping for.

      August 30, 2011 at 4:38 pm | Report abuse |
    • Amazed

      If you were in Irene's path and had the damage many of the areas have had, you wouldn't call it "a summer rain storm". Many have lost their homes, their businesses and a few, their loved ones. Don't be so quick to be so critical.

      August 30, 2011 at 4:43 pm | Report abuse |
  3. Vezalo

    Power just cut on about 10 minutes ago. Seemed like a pretty bad storm to us. Glad we listened and prepared. Yes the forecasters were off. But ,by the sound of these posts, it seems most of you wanted to see massive destruction and loss of life. Thankfully, the northeast did not get hit as hard as forecasted.

    August 30, 2011 at 4:29 pm | Report abuse |
    • Ralph

      I lived on the NC COAST for 7 years. I say listen and get out. It's for safety. Why do people complain when nothing happens? Be happy. 20 years ago there was NO WARNING. Now, there is some warning. Sometimes it's wrong. So what?

      August 30, 2011 at 4:37 pm | Report abuse |
  4. Twilighttrail

    Ye gods, why are we not glad that we know more than we used and have more warning than we used to? The weather is never going to be totally predictable. I am sure the families of the people who died think it was bad enough, and cities digging out from under will think the bill high enough. No matter how much technology we have NOTHING in this world will ever be 100% certain. Give the weather people and the media a break.

    August 30, 2011 at 4:29 pm | Report abuse |
  5. input

    just more BS from mainstream media. This was media driven hysteria with one goal in mind. An audience. Entertainment at it's most destructive. Now they will start on the next one and get the name as close to Katrina as they can.

    August 30, 2011 at 4:41 pm | Report abuse |
    • Auntie Warhol

      So there was no hurricane?

      August 30, 2011 at 4:49 pm | Report abuse |
    • Paul

      Tell the families of those who died in this storm that it was overhyped. No really, you who say this was overhyped please find out someone who died in this storm, give the families a call and tell them what wimps they are. The mayor of New Orleans killed 1200 people when he didn't order an evacuation. If New Jersey and NY had not ordered evacuations, the death toll would have been much higher than it was. Great job to all that got the word out.

      August 30, 2011 at 5:06 pm | Report abuse |
  6. john

    If recon planes can fly into the eye, out at sea, why can't they detonate a high explosive, causing hot dry air, collapsing the column of a hurricane?

    August 30, 2011 at 4:42 pm | Report abuse |
    • Bill

      as I read the article, I thought the same thing. you would think that if we could figure out how the hurricane works (which we did), we could shut it down.

      August 30, 2011 at 4:56 pm | Report abuse |
    • Timmy

      Because it can't be done:

      August 30, 2011 at 4:56 pm | Report abuse |
    • Bresson

      Well that couldn't be easier said than done, can it?

      August 30, 2011 at 5:02 pm | Report abuse |
    • MarkinFL

      If we could just find that dang switch!

      August 30, 2011 at 5:04 pm | Report abuse |
  7. 4F

    Why Irene's forecast missed the mark
    It would have been worse if these folks got their wishes:
    ✓ Bachmann prayed for total destruction of DC.
    ✓ Al Gore also wished for total destruction – Gore wanted to blame it all on global warming so he could perpetuate his environmental fraud.
    ✓ Ron Paul wanted wide-spread devastation so FEMA would be shown to be inept.
    ✓ Everyone wanted Obama to look bad – but really how hard is that to accomplish.
    Bottom line: God toned it down. He figured DC is not quite yet Sodom & Gomorrah.

    August 30, 2011 at 4:45 pm | Report abuse |
    • Auntie Warhol

      I guess those innocent people he killed were just collateral damage, eh? Good thing he toned it down...

      August 30, 2011 at 4:50 pm | Report abuse |
  8. KIlovolt

    The six other articles on CNN's front page under "Irene", suggest the forecast didn't "miss the mark". Where do you go with a story that isn't a story?

    August 30, 2011 at 4:46 pm | Report abuse |
    • MarkinFL

      Pretty scary huh? It was supposed to be much worse. Good thing it wasn't.

      August 30, 2011 at 5:06 pm | Report abuse |
  9. Alan Stephenson

    How can they say they got it right when Vermont and Upstate New York were devastated. They had everything going to Massachusetts and then up the coast. I must have seen fifty maps that showed it going that way. Not once did I hear or see any mention that it would hit Montreal

    August 30, 2011 at 4:46 pm | Report abuse |
    • Auntie Warhol

      You're referring to the center of rotation. A hurricane is hundreds of miles bigger than the center of rotation.

      August 30, 2011 at 4:52 pm | Report abuse |
  10. Patrick

    This is like what happens when tey get 1" of snow down south and it paralyzes the entire bible belt. People panic at what they are not accustomed to. This storm was a lamb in comparison to the Hurricanes down south.

    August 30, 2011 at 4:48 pm | Report abuse |
    • MarkinFL

      Difference is that the lambs don't cause sever flooding on the gulf coast. You drop that kind of water in hills and mountains and it is a completely different kind of animal.

      August 30, 2011 at 5:07 pm | Report abuse |
    • gremlinus

      What MarkinFL said. My husband is from Appalachia and 2" of rain in one day there is a lot worse than 2" of rain in FL. In FL it runs off. In KY it pools in the valleys. Where the people live. Also there are a lot of mechanisms in place in places where they get more hurricanes. Snow is the same way. I imagine in Michigan they would laugh at 1" of snow or even 6". One inch is enough to almost paralyze a decent size southern city. When I lived in Louisville and we got like 18", we only had one or two plows for the whole city. We were out for weeks.

      August 30, 2011 at 6:53 pm | Report abuse |
  11. Treehouseview

    Weather predictors are damned if they do and damned if they don't. It's weather, and for ions it has done what it's wanted. We have come to rely on weather forecasters, who do their best, yet if they get it wrong, then people complain. If they get it right, there's really no accolades for them. Use common sense with a slight bit of information given and stay out of harms way. And if the storm doesn't hit you, then just be thankful, and don't slam the person who was trying to predict it.

    August 30, 2011 at 4:50 pm | Report abuse |
  12. Gerry

    Yessir, I woulda stood out there, naked as the day I was born, shouting into hundred-mile-an-hour winds, "Is that all you got? I can take it! I'm a man! You can't hurt me!". And then I woulda climbed up to my roof, and waited for the wall of water to come hurtlin' down the road, like a runaway freight train. And just in the nick of time, I woulda stepped out on to some debris flying by on the cresting wave, someone's roof maybe, or a picnic table. And then I woulda surfed that bad boy all the way to Ohio, laughing all the while, shaking my fists at the sky, fearing nothing in this universe. Why, I coulda been The Hero of The Storm!

    But the TV told me I could get killed by a flying street sign, so I packed up the kids in the minivan and drove to Altoona for the weekend.

    August 30, 2011 at 4:51 pm | Report abuse |
  13. Bella10

    I would say it's better to over-estimate in a situation like this than to under-estimate. It's a hurricane, an act of nature, no one can possibly accurately predict exactly what is going to happen with it. In this day and age there is so much mass media people can see the satellite images and should have the sense to know they should get out of harms way without relying on NOAA, the government or anyone else to tell them. If they choose to stay that's their decision. My heart goes out to all who have been affected by this disaster. Most of us will resume our normal lives in a few days and this storm will be a fading memory. Those who live in its path will feel the affects for years to come. Lastly I would say to all who come on these boards and think you are clever, or funny by spewing your nasty words, you're neither funny nor clever. You are mean and hateful and someday you may be faced with a situation like this storm and then you won't be so quick to make your snarky comments – and won't appreciate those who do.

    August 30, 2011 at 4:52 pm | Report abuse |
  14. Joe_2Timez

    Nyc got very luck; even with the damage done, throughout the tri-state area and nj, it was nothing compared to what was expected of the hurricane. Realistically, they give you assumptions and theories into explaining certain environmental activities! They are thories! Not Facts! You dont know what is going to happen cause its not in the hands of humans but in the hands of God!

    August 30, 2011 at 4:54 pm | Report abuse |
  15. Joe_2Timez


    August 30, 2011 at 4:55 pm | Report abuse |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26