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. Abycats2

    Does the word 'forecast' tell you anything? Don't fool with mother nature.

    August 30, 2011 at 6:05 pm | Report abuse |
  2. Ron

    I thought they did a pretty darn good job of predicting where and when the storm would hit. It's also a LOT better for them to err on the strong side than the weak side. Right now, people are complaining that they were inconvenienced for a day because the forecast was wrong. If things were reversed, people could be complaining that everyone in their family was wiped out because the forecast was wrong. I'd rather the inconvenience.

    August 30, 2011 at 6:05 pm | Report abuse |
  3. tlobe

    Weather forecasters and public officials did not miss the mark. CNN did, however. CNN hyped the storm too such an extant that when NYC (the center of the solar system, of course) was not devasted, then everyone lied to New Yorkers, the world, and, most importantly, CNN. Poor Anderson Cooper now he won;t be able to stand in the middle of Wall Street and point to all the broken glass, dead people and aquatic species, and all the expensive yachts washed up on the streets of the "naked city." Screw you CNN and Gerald Ford said it right, Drop Dead New York(ers).

    August 30, 2011 at 6:07 pm | Report abuse |
    • rmm1231

      "Drop Dead" quote was never said by Gerald Ford.

      August 30, 2011 at 6:48 pm | Report abuse |
    • Robert

      Correct. Don't remember Hurricane Katrina getting that kind of hype even though they were almost certain it would hit land. And when they did report it, the concerns were with gas price gouging and refineries being shut down. Waiting for the next 0.1 earthquake to hit NY so we can hear about it for 5 weeks.

      August 30, 2011 at 7:10 pm | Report abuse |
    • Ira

      This is fine...the problem is when forecasters, like Chad Myers, make their predictions without even seeming to allow that they might be arrogance that can be prevented if they include as part of their forecasts where they might go wrong. Bigger point is that this is all about ratings...there is no way CN wants to report that the storm is weakening, because they lose viewers.

      August 30, 2011 at 7:22 pm | Report abuse |
  4. dakpluto

    It's Charley, not Charlie

    August 30, 2011 at 6:15 pm | Report abuse |
    • Jeltez42

      On the contrary. They were talking about hurricane Charlie (1951), not hurricane Charley (2004).

      August 30, 2011 at 7:34 pm | Report abuse |
  5. Dan

    They have a hard enough time predicting thunderstorms. They keep moving them and then canceling them. They've done this like 25 days this summer.

    Have you kicked the snot of out of a DC meter maid today?

    August 30, 2011 at 6:19 pm | Report abuse |
  6. Hank

    We live across the street from Chesapeake Bay on the Virginia eastern shore across from Norfolk. We had very high winds, rain etc. for about 24 hrs, but the ongoing forecasts missed the mark by a lot in terms of threats and damage (we have brick houses and didn't lose power), versus the havoc it created in more densely urbanized areas throughout Irene's path. But the problem was not the storm, it was the densely populated northeastern area with little ability for heavy rains to go anywhere except to flood.

    August 30, 2011 at 6:32 pm | Report abuse |
  7. gremlinus

    Because CFD and Atmospheric Science is HARD. Honestly with all of the models, we still can't do that much better than reliance on historical data. I model other fluids systems on the scale of meters and my simulations take days to run sometimes.

    August 30, 2011 at 6:47 pm | Report abuse |
    • Jeltez42

      Thank you for sharing that modeling a dynamic system is not as easy as typing in the location, wind speed and temperature, then hitting the any key. Atmospheric models leave out a good deal of the finer data points because it would take a hours to a day or so. By then they storm has long since moved on.

      August 30, 2011 at 7:39 pm | Report abuse |
  8. Suncatcher

    New England forecasters got it right. CNN and the WeatherChannel did their utmost to sensationalize a dangerous storm. I watch Boston and Springfield meteorologists and catch too if I want to know what is really going to happen weather wise.

    August 30, 2011 at 6:50 pm | Report abuse |
  9. Sunkanmi

    the scientist did not miss the mark with regard to the hurricane strength but some of took it to the Lord in Prayer specifically believing that "if you shall say to this mountain" we spoke to that hurricane and it heard the voice of God. its answer to prayer not an indictment on the scientist

    August 30, 2011 at 6:55 pm | Report abuse |
  10. xjthorn

    You can expect them to over forecast and over prepare foreever more to avoid being blamed. That was the lesson learned after George Bush caused Katrina and after Bush was responsible for $$ billions of damage in LA. I think Bush killed quite a few homeless and babies too during that huricane.

    August 30, 2011 at 6:58 pm | Report abuse |
  11. Richard

    Its beyond me why there are articles written saying the forecasters missed the mark. Ask the people of Vermont how bad the storm was.

    August 30, 2011 at 6:59 pm | Report abuse |
  12. Dammit

    I know we're the priveleged species and all, and how dare that hurricane not be precisely as advertised, but here's the thing: nature is wild and unpredictable and beyond our control. Take weather forecasts for what they are: horoscopes with numbers.

    August 30, 2011 at 7:18 pm | Report abuse |
  13. DCRed

    Did anyone see the satellite photos of Irene heading for the most populated part of the country? What else would you do but warn people about it? Repeatedly, since they don't seem to react to anything except hyperbole.

    August 30, 2011 at 7:32 pm | Report abuse |
  14. Brian

    Before a storm hits these forecasters talk like they have Papal infallibility. Afterwards they can give you a hundred reasons why they missed the forecast. I watched this hurricane on the Goes 8 satellite and two days before it reached NY I could see it was breaking up. Media hype is part of the problem.

    August 30, 2011 at 7:42 pm | Report abuse |
  15. zlul

    uh sounds like CNN got it wrong. They provided every single detail about the storm. Direction, movement speed, strength, etc. CNN just decided to hype it up like it was the storm of the century and that it was going to be worse than katrina.

    August 30, 2011 at 7:43 pm | Report abuse |
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