August 29, 2011

When Did Irene Stop Being a Hurricane?

On Sunday morning Anderson Cooper of CNN was asking about the strong winds that were being forecast and this brings up something that has really bothered me about the storm:  there is really no reliable evidence of hurricane-force winds at any time the storm was over North Carolina or moving up the East Coast.

First, what is a hurricane?  The official definition is that a hurricane is a tropical cyclone with SUSTAINED winds of 64 kt or more  (74 mph or more).  A gust of 65 kt  or more does not indicate a hurricane unless the sustained winds reach 64 kt.

I took a look at all the observations over Virgina, Maryland, Delaware, New Jersey, and New York.  Not one National Weather Service or FAA observation location, not one buoy observations, none reach the requisite wind speed.  Most were not even close.

Surely, one of the observations upwind of landfall, over Cape Hatteras or one of the other barrier island locations, indicated hurricane-force sustained winds?  Amazingly, the answer is still no.

Here is a map for reference.  The strongest winds I could find was at Cape Hatteras (CLKN7) where the winds got to 59 kt.

Or buoy 36, south of Cape Hatteras over the water...only got to 49 kt there.

Or plot the winds when the storm was just making sustained winds even close (see graphic).  Solid triangle is 50 knots, big line is 10 kts, small line is 5 kts.  Look for a triangle, solid line and small line (65 kt), or more....none exist.

Yes, there were a handful of hurricane-force wind reports but none of them were from official stations and there is considerable doubt about their reliability.  Furthermore, satellite imagery clearly showed a poorly formed storm off of North Carolina--with little evidence of an eye.

The truth is that there was little chance of intensification of the system as it moved up the East Coast.   Storms derive their energy from warm ocean water and the second the storm made landfall half of the storm was over land--which saps the strength of the system.  The other half was over increasingly cool water.  This system was toast.   But as a tropical storm weakens and "goes extratropical" there is a tendency for the precipitation to swing to the W an NW of the storm.  That is exactly what happened .  The big threat was flooding, not winds.

I assume that upon further study the NWS will eventually downgrade this storm as it moved up the East Coast.  Considering the tendency for media to hype storms it it crucial for meteorologists to stick to the exact story and not overwarn in the hope of encouraging people to take effective action.  If the storm was known NOT to be a hurricane earlier might the Mayor of NY have held off closing the City down, thus saving billions of dollars?


  1. Cliff- Great analysis, and I agree with you. Unfortunately, it won't make any difference. NY/DC consider themselves to be the centers of the universe (financial and government, respectively), and nothing that might be said will change that. You're dealing with people who are proud of the fact that they haven't taken a vacation in several years (why the world might stop if they took a day off, of course, that might be a cause of the hype, but that's a story for another day).

  2. Cliff,
    I find this very interesting.. why were the NHC advisories still calling it a hurricane with such high winds if it wasn't?

    Advisory 19 talks about a plane reading on the pressure:

    Advisory 21 hurricane hunter aircraft

    Air Force recon plane:

    NOAA hurricane hunter

    Air Force hurricane hunter specifically reported winds

    Two different hurricane hunter aircraft reported pressures right before the storm made landfall in NC

    Air Force hurricane hunter reports 90 mph wind

    On the ground; sustained winds reported at 85 mph

    How did SO MANY planes measure things and get it so wrong? I'm not saying they're right; certainly, the damage at my dad's beach place in Bogue Banks NC would argue that this was not so bad (according to my dad "a piss-poor excuse for a hurricane").

    If NYC was staring down a Cat 3 in NC that might be a Cat 1 by the time it hit Manhattan, then I think they made good decisions BASED ON WIND. If it was a Cat 1 in NC and just a tropical storm by NYC, then the decision is more questionable but likely still good based on existing ground saturation and the amount of rain expected from Irene.

    Certainly, they scared people too much. Hurricanes, after all, are just wind, rain, and punishing surf, often with added tornado spin-offs; they're not a special color, they don't have fangs, and they don't shout at people (so many people were so disappointed in how not-scary it was that it's easy to wonder what people really did expect!) I hope this doesn't make people ignore the next hurricane that comes up the Eastern seaboard. Most people in NC and further south know better because they remember true monster hurricanes of the past, but people in NYC don't have the same experience.

  3. It's also important to remember that the NHC uses a 1 minute averaging time for reporting the sustained (i.e. relatively long-lasting) winds. The maximum sustained wind mentioned in the advisories that NHC issues for tropical storms and hurricanes are the highest 1 minute surface winds occurring within the circulation of the system. These "surface" winds are those observed (or, more often, estimated) to occur at the standard meteorological height of 10 meters (33 feet) in an unobstructed exposure (i.e., not blocked by buildings or trees).


  4. Cliff,

    I had the joy of vacationing on the east coast for the past four days. All of the news reports over here did downgrade it to a tropical storm, granted after it landed in North Carolina... but more importantly, every word of warning was around flooding... and those warnings came for the NWS, CNN, NBC and state governors that were providing updates as they could. A lot of us did sustain damage, and many are still without power. I might be one of the few, but I'm more then happy that there was so much "hype" about this storm so that everyone could be more then well prepared.

  5. In terms of evacs, the decision to be overly cautious must have had a lot to do with political influences - nobody wants a repeat of the way Katrina was handled.

  6. Cliff,

    Long-time reader, first time chiming in. In case you haven't seen this little piece of "commentary", seems the NWS can't win for loosing.

    Best, JG

  7. Your observation begs in interesting question about Irene: Given that the winds were not that bad, why did so many trees fall, causing such widespread power outages?

    The answer is another essential reason that we must switch to clean energy sources and DRASTICALLY reduce emissions, not just from CO2 but the "other" greenhouse gases that create air pollution - because trees are dying from exposure to tropospheric ozone. All around the northern hemisphere, they are turning fall color already in summer, if the leaves aren't just shriveling up and falling off. Pine needles - especially the inner layers that have been exposed to multiple seasons of tropospheric ozone - are yellowing and dropping. Just go outside and look at them! This is as true for areas that have had normal or extra precipitation as areas that have been dry.

    That ozone is toxic to vegetation (and people, causing epidemics of cancer, emphysema and asthma) isn't a secret. It's just "the biggest environmental disaster you've never heard of"...because scientists and policy makers know the only way to stop sending emissions of ozone precursors like nitrous oxide into the atmosphere is to sacrifice our energy-gobbling habits, and radically curtail our current lifestyle and use of energy. But the alternative is famine (annual crop yields and quality are stunted by ozone too) and losing trees means a collapse of the ecosystem upon which we depend, not least for the oxygen we breathe.

    Links to research and photographs of Irene's aftermath here:

  8. Cliff,
    Thanks for some sensibility to the usual media hype. And while a lot of people had power outages and flooded basements (some relatives of mine included) this is not all that unusual for the east coast. It seems to me that there was far more damage and pain in this past Spring's tornado outbreaks.

  9. That item pointed out by drjwg could really use a proper Cliff Mass treatment. The authors are astoundingly myopic, selectively so judging from how they were able to seek out "evidence" to support their absurd premise.

    Back on the Irene topic, Jeff Masters has a nice summary regarding precipitation, here:

  10. Cliff, prepare to be "slashdotted".

  11. You got Slashdotted.... It is pretty cool when that happens.

  12. The decision to shut down the transit systems turned out to be 100% correct as multiple mudslides, fallen limbs and telephone poles, not to mention outright flooding affected every single railroad in New York City.

    The warnings I heard were 100% about flooding, almost nothing about wind and they turned out to be correct.

    The only place I heard hype was from Fox News who kept showing footage from the 1938 "Long Island Express" Cat 3 storm, insisting that this storm was going to be similar.

  13. They presumably use Doppler radar, which can measure speeds throughout the system, instead of relying on point sources, which can't.

  14. Cliff, you have several interesting points. You might also want to consider that all of the sites were on the left side of the hurricane. In my experience, most, if not all, locations on the retreating side experience much lower wind speeds (10mph-30mph) than locatios on the advancing side of the storm.

  15. Congrats on being slashdotted! I've made you our quote of the week.

    I had similar observations at the time:

  16. "Given that the winds were not that bad, why did so many trees fall, causing such widespread power outages?"

    We've had three storms here in Ohio which blew down trees since spring this year, and not one of 'em got labelled a hurricane (and only one made national news... for tornados a couple of hundred miles away).

  17. The wind aloft were much stronger than the winds at the surface.

    You can check upper level winds at which uses a lot of automated collecting from airplanes to make relatively accurate forecasts of what the winds are doing at the upper levels of the atmosphere.

    The strongest winds that I saw during Irene were at 4000ft which were pretty consistently 20 knots faster than the surface winds. (I'm an air traffic controller)

  18. Personally I considered it more a statement on hurricane politics than East Coast Narcissism. No one wants to be the person who appears sleeping at the wheel, a la Katrina. What was that dip-wads name who was head of FEMA again?

  19. Exactly Geoffrey Landis in Ohio. As a friend just pointed out (who lives in Massachusetts) trees that made it through numerous much worse storms in the past, including wintertime nor'easters laden with ice and snow, have fallen.

    It's not normal. Our trees are dangerously weakened. In fact I have an Amtrak ticket to go to DC tomorrow, to join the arrests at the Tar Sands protest in front of the White House - and it's no good because the tracks are covered with fallen I'm scrambling for a ride.

  20. We in manhattan may consider ourselves fortunate. And yes, in terms of wind force gales, this storm is not what was expected.

    If we take a look at our neighbors in New Jersey, Long Island, Westchester and points north (Vermont, rural MA) then quite a different cup of tea, isn't it?

    The storm's damage is from flooding. In terms of insured loss, this is quite a disaster.

  21. Gail said, " ... trees that made it through numerous much worse storms in the past, including wintertime nor'easters laden with ice and snow, have fallen."

    And every year, people who have lived for seventy, eighty or ninety years pass away. People get old and infirm. Trees get old, big, gangly, weak, infected and eventually come down. If they didn't, there wouldn't be room for any new ones.

  22. "And every year, people who have lived for seventy, eighty or ninety years pass away. People get old and infirm. Trees get old, big, gangly, weak, infected and eventually come down. If they didn't, there wouldn't be room for any new ones."

    That would be a just brilliant observation except for one little problem. MOST species of trees, unlike people, normally live for CENTURIES. So yeah, they do of course pass away. But not when they are 20, 50 or even 100 years old.

    Captcha is..shmeessi. Which pretty well captures you level of intellectual capabilities.

  23. Gail,

    Are you the same Gail that claimed in Feb 09 at the old Wonk Room that NOTHING was going to survive that winter in New Jersey? I believe something to the effect that ALL the trees were dying and there would be NO crops that coming growing season.

    I thought I recognized of writing.

  24. maybe you should have looked at the cumulative wind maps on

    hurricane force winds didn't really make it too far to land. Once it hit NC, the eye weakened.

    I've been through plenty of extremely devastating hurricanes here in Miami.
    In fact, every one since 1980.

    Tropical storm force winds are not an emergency. They are cause to be cautious and prepared. However, in places that don't expect hurricanes too often like NC, they aren't as prepared. As for NYC, the hype was purely political. When hurricanes hit, we fire up the generators and get out the camp stoves. It's a way of life to deal with extreme storms here.

    We do not panic. We do not hope the federal government will come in and give us debit cards with welfare.

    I'll bet you didn't realize that in 2005, we got hit by Katrina(cat1), Rita(cat1) and Wilma(cat2) all in the same season. There was an awful lot of damage that season.

    I don't remember the media making a huge hype about Miami. Not since Andrew '92

  25. "Considering the tendency for media to hype storms it it crucial for meteorologists to stick to the exact story and not overwarn in the hope of encouraging people to take effective action" ... So where does The Weather Channel fit into this equation? ;-)

  26. JPtech, How many folks in NYC do you think have emergency generators or camp stoves to fire up?

    I miss the point of your comment particularly the bit about preparations being political. There is nothing easy about decisions affecting the lives and livelihoods of millions.

    Cliff, you just added a few more bits of kindling for the folks who would like to burn down the house. How do you think defunding the NWS would affect your program at UW?

    I really value the work of NWS and look forward to the contribution that will be made by our new radar in Copalis Beach.

    Analyzing forecasts after the fact is a valuable exercise that is probably best conducted amongst the experts rather than in the blogosphere. Have you discussed your analysis with Jeff at Wunderground?

    Paul Middents
    Silverdale & Copalis Beach

  27. From the LA Times earlier this evening:
    "More than 48 hours after Irene made landfall early Saturday, about 4.5 million people remained without power in Washington and 13 states from North Carolina to Maine. The death toll was at least 40, the Associated Press reported, and some rivers had yet to crest, meaning flooding might not be over. Hundreds remained stranded in communities cut off by washed-out roads, including at least 2,500 residents of remote Hatteras Island in North Carolina...."
    But, hey, it wasn't a hurricane, so, no big deal, right?

  28. Gail, having grown up in Seattle, I know that when we get moderate windstorms with saturated ground, trees come down. Lots of them. I have seen plenty of people talking about saturated ground in Irene's path re: flood dangers, so I would guess that it played at least some part.

    (Yep, I'm an asthma sufferer, and I know about tropospheric ozone, but it's never just one thing that causes it!)

  29. Irene's central pressure of 950 millibars after landfall in NC made her tantamount to a Cat 3 hurricane, whatever her wind speeds were. And she was so enormous and dumped so much rain that epic flooding is now occurring from NC to Vermont. A lot of folks who refused to evacuate are now isolated in the midst of rising floodwaters and waiting for rescue.

  30. Big hurricanes like Irene don't stop being "mega-Katrinas" just because their winds peter out and their eyes fade away. The media need them far too much to let that happen. I mean, such storms "prove" once and for all that global warming is real, it's man-made and it's getting worse. What more could you ask of a confused, candy-ass, down on its luck tropical storm?

  31. Big hurricanes like Irene don't stop being "mega-Katrinas" just because their winds peter out and their eyes fade away. The media need them far too much to let that happen. I mean, such storms "prove" once and for all that global warming is real, it's man-made and it's getting worse. What more could you ask of a confused, candy-ass, down on its luck tropical storm?

  32. Big hurricanes like Irene don't stop being "mega-Katrinas" just because their winds peter out and their eyes fade away. The media need them far too much to let that happen. I mean, such storms "prove" once and for all that global warming is real, it's man-made and it's getting worse. What more could you ask of a confused, candy-ass, down on its luck tropical storm?

  33. The implication of this and your previous post seems to be that the people of the northeast are weak, self centered babies who worry about storm systems too much. First of all, the population density is WAY higher here than in WA or even NC or FL. The reason the media covers events here is that these are the largest media markets. Basically, no one cares if there is bad weather in Queets--it's economics, not a media conspiracy.

    Also, there was a very high +5.5 tide predicted for 8/28, pushed by strong on-shore winds over a long fetch, hence the heightened concerns about flooding.

    Also, we have mudslides, deciduous forests, skyscrapers and extensive infrastructure below sea level including roads and rail networks. They've never shut down the subways on Miami or Forks, WA, why? Because they have no subways there (Miami Metrorail is elevated, Forks is barely paved). It was hugely complicated to move all the trains out of the storage yard at Coney Island and find places for them at higher altitude--its not something you can do in a couple of hours when you start noticing a problem. I don't know if you all think everyone in NYC panicked, but most people were pretty psyched to get an unexpected 3 day weekend and an excuse to sit around drinking and watching videos.

  34. The trees fell because the ground was saturated and the roots couldn't hold. Many trees are shallowed rooted...duh. That really is a no-brainer, you climate freaks.

  35. Rita and Katrina were both Cat 5. Look it up JPTech. IKE was a Cat 3. The rains can be a problem, local tornadic activity that isnt registered on buoys. But the east coast is made up of whiners.

  36. Hi All, I believe Cliff has stated that we know more about the track a hurricane will take then we know of the intensity a hurricane will have. If this is true, then it is understandable to err on the side of safety even if we have to suffer some avoidable costs. I'll leave it to the meteorologists to decide if correct message got out about this amazing storm. R

  37. M...I'm touched that what I said years ago at the Wonkroom resonated so much with you that you actually remember it! It makes me feel like maybe it's not a total waste of time, trying to raise people's awareness that the ecosystem upon which we depend is collapsing.

    True, I was off the mark. But so was Ehrich, and Hansen about SLR. But, it's the trend that is important, and in that I was quite correct. Many, many trees do not have any leaves, and there are NONE that have the full complement they should. Have you looked at any lately?

    Agricultural experts around the world for decades have recognized that crop yield and quality are stunted from exposure to tropospheric ozone, and since the background levels are inexorably increasing, that too is a dangerous trend. Ask any backyard gardener how their tomatos are doing this year.

    A friend of mine once said, "Zawacki is a verb that means I told you so."

    Ha well, I have to pack. Last time I went to DC to protest I actually got my picture taken with Dr. Hansen. They posted it at the Wonkette here:

  38. Great thread. We went through Irene here in the Hudson Valley and yes, no huge winds but the flooding is intense. We have gotten way more rain this month than normal, the ground is beyond saturated, and older root systems cannot support very large trees in many cases. Those are the ones that came down. However, there are still millions of old growth trees standing just fine here in NY. More trees were lost in that NE ice storm of the late 90s by far.

    Not sure Gail has ever been to the NE. We are a complete forest, NO trees dying from "global warming" (which was utterly discredited 2 years ago). Further, as soon as I see "clean energy" and "emissions" in a post or comment, I know I'm looking at the dogmatic rant of a loon. Kinda like bloated gasbag Algore, someone you really do not want to be associated with. It's not the earth these people care about - it's that they just despise humanity.

  39. The trees didn't fall because of Tree Armageddon. They fell because it rained like hell on top of ground that was already saturated. Wet ground weakens root systems so that trees can't withstand relatively mild gusts. All the forecasters started predicting that exactly this would happen days before the storm -- and whaddaya know, they were right.

    As for the leaves changing, it's almost September. At this time of year you can always spot a few branches here and there that have gone gold or red, and if you look closely, all the foliage has begun to lose the deep green of summer and take on a golden tinge. It happens every year just like this, and it's not ozone or mustard gas or death rays. It's called autumn.

  40. Follow the money. Billions in disaster relief funds are being diverted from Joplin, Missouri and other red state areas to New York City and other Democrat strongholds. Reward your friends, punish your enemies. It's the Chicago Way!

  41. I am in Northern NJ and the whole thing here was about flooding. on their hourly forecast had winds ranging from 25mph to 36mph with gust to about 50. But we had lots of rain and places that I have never seen flood, flooded. Evacs - I can't say as that was south Jersey and I don't know what it was like down there.

  42. "MOST species of trees, unlike people, normally live for CENTURIES"

    I've never seen that claim made before.

    I've also never understood the passion for the post-event hype that overly examines the accuracy of the pre-event hype. In horse-racing, we call that "redboarding."

  43. I couldn't agree more. I too, was tracking Irene as it approached the NC coast, since we have properties there. None of the stations (NDBC, NOAA, NWS, etc..) showed any sustained winds approaching hurricane strength.

    I was wondering the same thing, since the hurricane center said hurricane force winds extended 70-90 miles from the center. Yet, none of the weather stations or data buoys supported that. At Cape Lookout, near where Irene made landfall, the sustained winds were less than 60 knots and rapidly trailed off as it passed. Even the trend line does not show anything above 60 knots. Same deal for the buoys out in the ocean.

    A lot of people wonder why any of the natives stay on the outer banks during a hurricane. Its experience, plus the internet!

  44. A lot of trees were not breaking in half, they were falling over. The ground was already pretty saturated before the heavy rains and winds. The roots could not hold them in the wet ground.

  45. @JPTech - As a South Florida resident as well...I totally agree. 2005 was a bad year for us, and the eye of Wilma passed about a mile from my house.

    But yes, we all here know how to deal with it. We do what needs to be done ahead of time and it isn't a major deal. But elsewhere in the NE US the situation isn't the same, and they aren't prepared.

    But going to the politics I've seen in the last few days...this talk of disbanding the NWS is purely stupid talk. That along with the talk of eliminating federal disaster relief altogether. The fact is that if our tax dollars are going to fund something, this type of relief isn't the worst thing out there to spend it on.

  46. Cliff, I was watching the NOAA weather model (GFS) and others like COAMPS last week and they barely predicted hurricane winds at Hatteras, let alone north of there. In fact the NOAS GFS model predicted the Irene winds here in Maine almost perfectly two days before the fact, even though they were well below the text and audio forecasts!

  47. Gail,

    we are all stupider from having read your comment. You are awarded no points; may God have mercy on your soul.

  48. Maybe Gail should learn the difference between ozone depletion and global warming before she pushes her "green" agenda on another blog. We had a bad drought in much of the northeast US in July, and that was the only time I saw trees dropping leaves. The leaves stopped dropping after we got a mere 1/2" of rain, and by the second storm new ones were coming out. The misleading vividness of the drought has corrupted your logic.

  49. JPTech,

    Looks like south Florida received at least $3.5 billion in FEMA assistance during 2005 with major disaster declarations for Wilma, Dennis, and Katrina.

  50. I agree that we should be careful with our definitions. That said, I feel that the warnings were warranted as there were storm surges that came close to doing serious damage in NYC. As for trees falling, there were seriously saturated soils. Same for flooding. This was and is a dangerous storm. I posted the article on PNW Cyclones vs East Coast Hurricanes and started a facebook storm of opinions. I had to agree we are comparing apples to oranges. Whatever you call it, it was a serious storm and everyone is better safe than sorry.

  51. Gail said, "MOST species of trees, unlike people, normally live for CENTURIES. So yeah, they do of course pass away. But not when they are 20, 50 or even 100 years old."

    Please familiarize yourself with the concept of succession.

    Succession ends in a climax forest filled solidly with two or three species of trees, all large and mature and long lived. High winds blow over the top of the canopy, not through it so there is little windfall. If you spent much time in such an environment you would know this. Also, walking through such a forest you’ll notice that trees that have come down haven’t broken but rather have pulled their roots out, weakened by saturated soil and/or erosion.

    Climax forests are rare. Most of us experience isolated stands of trees or single trees or mixed landscape that allows wind to get into and under the canopy to break trees and/or bring them down. Also, we dig up the ground, damaging root systems, cutting off natural water flows or causing erosion further weakening trees.

    And of course, no one notices a fallen tree unless it blocks a road, brings down a wire or takes off someone’s back porch. None of those things happen in an uninhabited, mature, natural, climax forest.

  52. Are you suggesting, as Monday morning quarterback, that the warnings along the coast of New England should have been Tropical Storm Warnings instead of Hurricane Warnings?

    Further to the point about the bigger threat being flooding and not wind, what was the rationale for Brown/Franklin of the NHC who authored Irene Discussion 30 when they stated:

    "More so than with most storms...the winds with Irene increase sharply with height above the surface."? More so than most "storms"? What kind of storms? Tropical storms? Extratropical storms? They went on to scare people in Manhattan by saying, "As Irene moves through areas with high-rise structures...these structures will experience winds significantly stronger than indicated by the advisory intensity. Winds at the 30-story level will likely be 20 percent higher than at the surface...and winds 80-100 stories up could be about 30 percent higher than at the surface."

    Wow! So if NHC was treating Irene as a Hurricane (with Hurricane Warnings indicating a Hurricane was imminent), then those city skyscrapers and high rise condos must have been jeopardy and the wind stress must have surely knocked out quite a few windows right? The 30 story high rise concern doesn't really compute (and the 80 to 100 story) is marginal, based on [Anthes 1982] vertical wind profile of a typical hurricane. Oh wait a minute, Anthes was referring to a "hurricane", what Mass has argued is that we had a Tropical Storm (which probably reduces the need even further for Brown/Franklin to cackle about high rises which of course the doodads at The Weather Channel at one point simply aped ("rip and read") without questioning or giving this any critical thought or providing the audience with any further explanation.

    It is also disappointing to read blog posts from venerable TV meteorologists and AMS Fellows like Tom Skilling of Chicago who posted (last Friday) comments which implied something more for people to worry about more (how probable was the Gulf Stream influence?) ...

    > Category 3 Hurricane Irene,
    > with 115 mph sustained winds
    > late Thursday, could grow
    > even stronger after its trek
    > across the warm Gulf Stream
    > Friday.

    Which model / ensemble was cherry picked for such a (probable?) outcome.

  53. Cliff: I like this post, as it relates to how we define storms. A good article to look at, however, in relation to the so called media hype is over at

    Given the loss of life, at this point, this storm ranks #4 since 1980. Was it over-hyped? Or was the media reporting the wrong things to be concerned about (winds vs. rain/flooding)?


  54. Nate Silver, using available and preliminary damage information, finds that this storm has created damage equal to a category 3 hurricane. Those contrarians who are trying to say this was not a major and dangerous storm are making themselves look poorly. Serious flooding is still going on.

  55. Cliff,
    It seems to me that when you read the NHC forecast discussions for tropical cyclones, they generally err on the side of caution and lag behind the actual intensity when they downgrade a storm, whether it is making landfall or not. They want to make sure it is not going to restrengthen. This was exactly the case with Irene, where they were expecting an eyewall replacement cycle and associated rapid intensification to occur as she made landfall. The secondary eyewall never contracted though, so winds remained weaker than expected. They were also very careful in every discussion and public advisory to mention that whether Irene was a cat 1 or a tropical storm, preparations should be made regardless because of the immense size of the storm - the effects were not going to be much different.

    - Bonnie

  56. said...

    Congrats on being slashdotted! I've made you our quote of the week.

    Flattery of dubious provenance. Cliff is inadvertently conscripted into the Wattsian army, joining such seasoned volunteer veterans as Steven Goddard, Joe Bastardi.

    Proof once more that bad things can happen to good people and no good deed goes unpunished :-)

  57. Wind-wise, Irene didn't seem significantly different than the usual run of tropical storms or 'Noreasters we get here in South Jersey in a year. I have yet to have a tree downed by wind, on my 26 acre tree farm... then again, it's mostly oak, poplar, maple and beech. No pines.

    On the other hand, we had the worst power outages I've seen in the area, period. It took Atlantic City Electric 41 hours to get my power back on. And this was more rain than usual, on top of 10" from the previous week-and-a-half, so I had cellar flooding for the first time, thanks to the extra water and lack of power for the sump.

    And yeah, more trees down in the general area than I've seen before. I passed an area this morning that had had several trees downed, and the road is still closed, two full days after the storm left.

  58. The maximum wind speeds anywhere in the storm measured over a 1-minute period determines the classification.

    Even if a small section of the storm (usually near eastern side of the eye) measures winds over 73mph for 60 seconds or more, the storm is a hurricane. Even if the parts that actually made landfall only had tropical storm wind speeds.

    So yes, Irene was correctly classified as a Category 1 hurricane when it made its final landfall.

    Flooding from the storm surge is the most devastating effects of any hurricane. High winds may look impressive on video, but the storm surge is what you need to worry about.

    Since Irene was such a large storm, even if it were "only" a tropical storm, it still would have had a similar effect on the areas hit hardest.

  59. I don't get it. There was substantial property damage and 40 or so deaths. What fractional changes at any moment for the worse would have made the preparation and heads up unnecessary?

    Perhaps we should convert to a Bangladesh style weather service and civil preparation methodology.

  60. Mrs Whatsit said:

    "It's called autumn."

    Good job. Now Gail and her friends can spread the alarm about Hemiglobal Autumning! ;^}

  61. This thread went pretty crazy. That story that JG highlighted from Fox News back in the beginning of the thread is worth commenting on. I haven't read a more stupid article in a long time. Ridiculous.

  62. I love how people can figure out how to grind either their Tea Party or Green political axes on a weather thread. Neither axe makes much sense, unsurprisingly.

  63. Given the loss of life, at this point, this storm ranks #4 since 1980. Was it over-hyped? Or was the media reporting the wrong things to be concerned about (winds vs. rain/flooding)?

    I don't know about Cliff's view, but I question what is called a hurricane related death. Early on, the second reported death I heard was a guy who had a heart attack while boarding up his windows. A heart attack is not something I'd particularly blame on high winds, rain, lightning, or flood especially prior to those events occurring.

  64. Why was the NHC trotting a hurricane out if it wasn't a hurricane? That's easy. Because Obama was desperately hoping for a disaster in the same way that Bush was hoping for WMDs. Bureaucrats always take their queues from the top. If we're lucky, the President won't be able to get away with having FEMA occupy New England for the next 10 years.

  65. Describing Tharm's hypothesis more fully:

    -- President thinks to himself, "I sure do need a disaster, because after all things are not bad enough already and I need to take on another very risky challenge, incur more danger to my reputation."

    -- President communicates with Bill Read, Director of the National Hurricane Center, orders him to ignore any NHC internal analysis, maintain Irene at hurricane status regardless of data.

    -- Bill Read-- former US Navy officer serving as a meteorologist with the Hurricane Hunters and with a professional meteorology career spanning back to 1977-- obediently communicates the President's wishes to his staff, including analysts several paygrades lower in the NHS hierarchy.

    -- In a remarkable feat of close-lipped secrecy under scrutiny by a nationwide audience, workers at multiple levels within NHS manage to conceal the actual truth about Irene, convey instead false information.

    -- As part of the plan of deception, vast quantities of meteorological data are altered, subtly restructured so as to make it -appear- as though a hurricane happened when actually it did not. This work is accomplished on a realtime basis, a stunning feat in itself.

    -- Astoundingly, not a single staff person from Read on down int the NHS foodchain objects to the behind-the-scenes manipulation. Apparently an entire swathe of NHS personnel spanning nearly the entire organization are deeply corrupt.

    -- Despite overwhelming odds against it, the perfidious presidential plot succeeds, unlikely those this may seem.

    Sounds perfectly plausible to me.

  66. So, Doug...

    Using your reasoning, then, the fact that every one of the reporting stations measuring only tropical storm level winds throughout Irene's passage was part of a massive conspiracy to undermine Dear Leader's apotheosis...?

    Bozone poisoning indeed.

  67. The flooding was really the thing. New England may only get a storm that stays organized enough to resemble a hurricane about once every 20 or so hurricane seasons, but when it does the flooding can be catastrophic. (As we have seen in Vermont this week.) I watched the flood gauge on the Farmington River behind my mother's house and bit my fingernails all day Sunday and Monday.

    If it had been just a bit worse for New York, the flooding could have been extremely dangerous.

  68. Hair Bob, data is one thing, speculation is another. Tharn suggests that Obama guided NHC's public statements, meaning that NHC's press office would be the exposed point of a plan formed by Obama, working within NHC. When were the instructions issued? Prior to the North Carolina crossing? Afterwards?

    Tharn: Why was the NHC trotting a hurricane out if it wasn't a hurricane? That's easy. Because Obama...

    Ok, so -when- Obama, and -how- Obama? How exactly did this mechanism work, in detail?

    At a certain point we have to conclude that it's impossible to argue with somebody's emotions and imagination, I'll grant you that. This idea that NHC was parroting Obama's wishes is about 1mm removed from "Birther" fantasies, another intractable mental trap.

  69. Getting back to reality, Jeff Masters today posts some remarkable insights on intensity forecasting, the cost/benefit of running the NHC.

    Well worth a read:

    Grading the forecasts for Irene

    One of the things Masters mentions is the remarkably high cost per mile for evacuation as opposed to the relatively tiny cost of forecasting. Just a little bit of money spent on forecasting avoids vast sums wasted on needless evacuations.

    As now planned, "...the current proposed budget from the House of Representatives mandates a $400 million cut for NOAA, and the NOAA Hurricane Hunters are slated to have their budget cut by 40%, from $29 million to $17 million per year. If these cuts materialize, the ability of the NOAA Hurricane Hunters to continue to aid improvements in hurricane forecasting will be seriously impacted."

    Ouch, really. I'm trying but failing to see the parsimony in those cuts.

  70. Interesting thoughts:

    A couple of possible contributors to the confusion - Hurricane Katrina was huge in diameter miles, and definitely a hurricane before landfall - the resulting storm surge was devastating - more so than the wind.

    Hurricane Andrew accelerated to Cat 5 just before landfall just south of Miami.

    ??? Allison (Houston, many years ago)made landfall as a tropical storm, but dumped huge amounts of water on Houston - resulting in major damage.

    Why did New York shut down? Because of the threat of storm surge water damage to underground electrical, transportation systems, hospitals, plus accelerated velocity of the winds between tall buildings.

    Perhaps the threat of damage was too close to call with a large tropical system coming in, and they decided to err on the side of caution where infrastructure and hospital patients were concerned. Maybe because everyone heeded the warnings, we had no one out in harm's way.

    We all remember that Tropical Storm Allison disabled a hospital with critically ill patients needing emergency transport - a crisis.

    In view of the severe flood damages in 13 states and 45 fatalities, whether or not Irene was a hurricane while slamming into the East Coast seems to me to be less of a question to ask. The real question is - at what point do we tell people to risk staying home to wait it out, given the unpredictable nature of tropical systems?

  71. Given that you yourself posted that hurricane force is more difficult to predict than direction (or the predictions have not improved) I am very sorry to hear you complaining about whether those in the path of Irene should have been told not to do things like shut NYC down. I live in Rhode Island and was very glad we were prepared for the worst. In fact hundreds of trees and limbs came down in our neighborhood,we were without power for 58 hours, some are still without power and water because many have their own wells. I heard about others whose plywood shutters blew off and saidon the radio, they really were not prepared for even the force of wind we got. I read your blog because I lived in Seattle last year for six months. But this time I believe the tone of your blog feeds into the annoying wave of all the others who think they know better than someone else about this hurrican, usually those less well informed. By the way I am an oceanographer at URI.

  72. What a crock. Let's start with wind speeds. Obviously the strongest winds would be on the Eastern side of the storm, especially in the NE quadrant. Not on the Western side that was onshore. Just because the winds on land may not have been sustained at hurricane force doesn't mean there weren't winds else where in the system that were. Obviously the NHC recon plane found these winds as the storm remained classified as a hurricane. Also it maintained a central pressure of around 950mb most of the way up the cost, pressures normally associated with a Cat 2 or 3 hurricane. Also did you notice many of the land based weather stations stopped reporting as Irene moved closer? Many of them failed due to power outages, Internet outages, and possibly failures of the stations themselves. There were certainly plenty of hurricane force gusts around, and tornadoes. Also the inland flooding was horrific and historic in many places. Irene stopped being a Hurricane when it was downgraded to a tropical storm by the NHC, not when you feel it should have been based on wind speed readings taken by various stations. When Katrina hit it was hard to find stations reporting sustain hurricane forced winds, it almost always seems that way when hurricanes make landfall. Those types of winds can be elusive over land, or the weather stations fail, etc.

  73. Wade, you are wrong.

  74. I have lived in eastern NC for over 20 years and I've been through many hurricane seasons here. The thing about a hurricane is, even though you can track them for days or even weeks ahead of landfall, they still remain unpredictable in the end. And you never know just what the outcome will be, regardless of wind speed. Some bring intense flooding (the cumulative effects of Dennis and Floyd). Some swing randomly inland and take out Charlotte (Hugo). Irene caused massive flooding along the Pamlico, and more downed trees than most old-timers around here have seen in their lifetimes. Entire houses and roadways were washed away. Schools are closed indefinitely. People are suffering. The point is, the media should hype it up. You should be overly prepared. You should raid your local stores for every scrap of anything you think might be useful to you if you find yourself stranded with no power or running water for days on end. I'm so tired of hearing about how Irene was overblown in the media, they just used it for a ratings ploy, everyone overreacted, blah blah blah. It could have easily remained a Cat 2 or 3. The worst part is, articles like this will make people less likely to prepare in the future, which could lead to further loss of life and property. I invite to you to take a trip to Beaufort County, NC. You'll see the worst a hurricane has to offer.

  75. Really i appreciate the effort you made to share the knowledge.The topic here i found was really effective to the topic which i was researching for a long time.

  76. The other half was over increasingly cool water. This system was toast. But as a tropical storm weakens and "goes extratropical" there is a tendency for the precipitation to swing to the W an NW of the storm. That is exactly what happened . The big threat was flooding, not


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