Another Monster Goes *POOF*

[jes]

Mac,
I know exactly what you are talking about when you say "poof" and you are completely right to be concerned about the public's potential apathy when it comes to taking future storms seriously. I tend to feel that way myself.

[JQ Public]

the nasty hurricanes are probably 1 in 5 or 1 in 10. you seem to forget Charley from last year was definitly not a poofer. It seems that if the hurricane is strong days before landfall it will eventually lessen in strength. Its a part of the cycle. Normally hurricanes that can do the worst damage are those that are minimal up until about 200 miles to the coast and then they bomb. Also the fast moving hurricanes seem to maintain their strength faster and carry its effects further inland.

[Mac]

I suppose my thinking is that, with a better understanding of WHY a storm may gain or lose intensity in the critical hours leading up to landfall, the NHC and meteorolgists might be able to offer the public better explanations regarding preparations and why. Sure, in an ideal word all people should comply with evacuation orders. But the reality is that many people calculate odds--regarding the cost and inconvenience of evacuating vs. the potential risk of staying--and make their decisions accordingly. With several extremely powerful hurricanes diminishing in intensity shortly before landfall over the past couple of years, I fear evacuation decisions will be swayed towards gutting out the storms.

I don't think the average person really appreciates how lows, highs, SSTs, etc., factor into intensity and direction. I would really like to see an effort made to explain possibilities in the simplest of terms so the layman can fully understand the true risks.

[george_r_1961]

135 mph Category 4....no communication from Cozumel...that's poof?

Agreed. I find it amazing that when a storm goes from a Cat 5 to a Cat 4 that its considered poofing.

[SouthernWx]

Well, we have yet another monster hurricane that went *poof* at landfall.

It seems to me that we have been seeing quite a bit of this lately, with such storms as Dennis, Ivan, et al—monster hurricanes which fizzle out right before mainland landfall.

It's always been that way. In 1924, Tampa residents were warned a "200 mph killer hurricane" was on the way....which it was in Cuba (actually 150-155 mph or so); but it completely fell apart between Cuba and SW Florida....was barely a hurricane at Florida landfall.

This didn't just begin happening....there have always been some hurricanes which weakened rapidly just before landfall AND others which bombed into monsters at landfall....like the 1935 "Labor Day hurricane" and 1957's hurricane Audrey. Thanks to the information highway and 24 hour newscasts, we just notice hurricanes weakening and strengthening more closely

I’m talking about storms which seemed to have all the necessary ingredients to remain monster Cat 4/5 hurricanes all the way to a mainland coastline, but, for whatever reason, lost intensity just in the nick of time.

Emily DIDN'T have all the neccesary ingrediants to remain a monster....although in the NW Caribbean, it's always a possibility. Emily didn't just go "poof" my friend....she had been weakening slowly for hours-- the central pressure much higher (950-955 mb) than 18-24 hours earlier (929-930 mb. There was shear affecting Emily as it approached the Yucatan.....the weakening didn't surprise me; many models had forecast it.

While I am thankful that these storms spared lives and property, I find it a bittersweet victory when such storms diminish in strength right before landfall. I fear that this “diminishing strength” trend will cause more people to fall into harm’s way in the future. Evacuations are extremely costly and, let’s face it, downright disruptive and inconvenient.

Just another reason coastal residents need to learn all about hurricanes they can; to know what can happen. If anyone on Tybee Island, Miami Beach, or in Gulfport harbor fails to evacuate from an approaching powerful hurricane because "Ivan weakened".....then my friend, they are idiots. Don't ever judge the next hurricane threat by the last one to strike your area....that kind of logic is why 400 died in Cameron, Louisiana in 1957 and Pass Christian, Mississippi in 1969....they didn't believe it would be that bad....until it was (and too late to escape

Although Cozumel and Cancun obviously took some damage, initial reports would seem to indicate that they did not take nearly the damage that they could have—or perhaps should have.

Anyone looking over the USAF reconnaisance data should have known the core of severe winds (over 100 kts) was very small in diameter, even at peak intensity. If Emily missed Cozumel's beaches by even 30 miles, they got 75-100 mph winds instead of 130-140 mph....a helluva difference over a short distance. That isn't uncommon in severe hurricanes...why Homestead and Cutler Ridge were wiped from the earth during Andrew but Miami suffered minor damage.

It is obvious to me that there is still so much we do not understand about how hurricanes attain certain intensity, and how they maintain that intensity. There is also much we apparently don’t understand about how intensity correlates to damage.

duh!...that's why we have AOML and the Hurricane Research Division; to conduct research and try to learn why hurricanes sometimes bomb while some fall apart near landfall. Just as the National Severe Storms Lab re: tornadoes....we've learned a lot in the past, but still have much to learn.

I would really like to see this problem addressed. I would like to see more money poured into intensity research, so that we might garner a better understanding of how and why storms attain certain intensities, and the variables that play into maintaining intensity for a prescribed period of time. I think we’re missing the boat in this regard.

Have you ever heard of "state of the art" (or state of the science).
Why do some promising spring storms spawn dozens of killer tornadoes while an even more ominous storm system spawn nothing? Why do some nor'easters drop 3' of snow while others only bring heavy cold rain?
Why are some summers hot and others mild? BECAUSE IT'S GOD'S WORK....it's nature, and there are some things that are beyond comprehension, regardless of how talented the research scientists are or how advanced the newest "supercomputer" is.

You honestly are one of those folks who seems to expect too much of forecasters. Let me tell you from experience friend....give hurricane intensity forecasting a try. When you are humbled as I've been on a few occasions, you'll understand just how difficult it is to forecast intensity accurately; and no amount of research money will IMO give us a clear understanding anytime soon.

We've poured billions into medical research for decades....and people still die from cancer. While true, more folks today survive than in 1960 or 1989, people still sometimes die from it....just as my cousin Suz did in 2003...just as my sister's father in law is doing now (terminally ill w/ grade 4 prostate cancer). IMHO God almighty determines who lives and who died...just as he determines which hurricane falls apart before landfall and which blasts inland while deepening rapidly.

Just my .02¢ cents worth...from someone who's been learning about hurricanes the past 31 years...yet still gets fooled sometimes.

PW

My hurricane 05' site
http://community-2.webtv.net/SouthernWx61/Hurricane

[Mac]

the nasty hurricanes are probably 1 in 5 or 1 in 10. you seem to forget Charley from last year was definitly not a poofer. It seems that if the hurricane is strong days before landfall it will eventually lessen in strength. Its a part of the cycle. Normally hurricanes that can do the worst damage are those that are minimal up until about 200 miles to the coast and then they bomb. Also the fast moving hurricanes seem to maintain their strength faster and carry its effects further inland.

I've considered what you're saying--that hurricanes go through various life cycles--so only a certain percentage will actually hit as a stronger storm. I suppose a person could investigate this and arrive at statistical data by looking at various storms encountering various conditions over an extended period of time, and then calculating their average intensity vs. their intensity at landfall. If their intensity at landfall was approximately the same as their average intensity, then it would lend more credence to the "chance" theory of storm diminishment. But if the research indicated that storms are statistically weaker at landfall than they are over the average of their life, then that might indicate there could be more to this trend than initially meets the eye.

Thus, the need for further research. IMO

[vbhoutex]

Most of what I have seen over the last couple of years with these storms that seem to/do lose strength at landfall or that don't do the damage we would expect at landfall leads me to believe that we do not really understand how the winds mix down to the surface. In each of the storms mentioned above we have also seen swaths of severe damage and other areas, maybe even closer to the eye than the swath which were less damage. We need to remember a couple of things here. Some of the severe damage we see is probably caused by mini vortexs or tornados and even thought it is basically portrayed that way a hurricanes winds are not 135 mph everywhere within the core, just in a few places in seperate squalls. I think the perception of all these things make a big difference.

And another point-the average person-even a few who may read STORM2K don't care about a lot of the things we debate. They want to know if they need to evacuate or board up and want to be inconvenienced as little as possible. Even people in my family, who know what a weather weenie I am were woefully uninformed about the existence of a CAT4 hurricane named Emily that still might affect them. JMHO

[SouthernWx]

A couple other points I wish to make...

1) When you see a hurricane has 140, 150, or 165 mph sustained winds....please remember, except in rare cases (i.e.- Carla 1961; Luis 1995)...the violent winds are that intense over a very small area of the north or northeast eyewall. Look at those supplementary vortex charts sent back by recon aircraft....when Dennis had 150 kt flight level winds, it was only in a small area of the NE eyewall; when Dennis made landfall east of Pensacola, recon and Nexrad doppler velocity data showed the area of 100+ kt winds over an extremely small area....about 5-7 miles in width along the beachfronts (and BETWEEN Pensacola Beach and Navarre). The area of max sustained winds struck a national seashore with no condos or homes to destroy.

2) Before stating either Dennis or Emily went "poof"...check the calender. It is mid-July....when even 110 mph cat-2 hurricanes are climatologically unlikely. Between 1851 and 2004, only ONE lone cat-4 occurred during July....1 in 154 years. In this bizarre July 2005, we've already seen Dennis smash the record for most intense July hurricane of record....only to see Emily become even stronger less than two weeks later.

Why did Dennis weaken as it approached the Florida panhandle? The answer lies in the Tropical Cyclone Heat Potential charts from HRD. The TCHP (oceanic heat content) was simply NOT deep enough to sustain a cat-4 hurricane to landfall. This is an area where only one other cat-3 had ever occurred during July....so why should we have expected a cat-4??

Don't judge a climatologically out of season monster hurricane in the same way you would one a month or two from now. I have great confidence if Dennis had occurred in mid-August, it would have been a strong cat-4 hurricane smashing into the Florida panhandle....possibly a cat-5. The TCHP would have been much higher (which is the reason WHY hurricane Charley bombed from 964 to 941 mb in just a few hours before impacting SW Florida last year).

I don't look at hurricanes Dennis and Emily as "poofs" or "weak". I see them as extraordinary.....and give me great fear we may see a hurricane even stronger than Gilbert in late August or September. The sst's over much the deep tropical Atlantic are near record warmth....and unfavorable atmospheric parameters over the tropics are seemingly few and far between. That could mean a record breaking active hurricane season....and possibly a hurricane catastrophe for someone in August...September....or possibly even October

PW

[Mac]

There seems to be a tremdous amount of misunderstanding regarding what I meant by "POOF."

When I used the word "POOF" I did not mean it vanished...or it was weak. I merely meant that "POOF" the MONSTER disappeared. Now, that doesn't mean that a category 3 or 4 hurricane is unworthy of respect. I was just pointing out that Emily--an extremely powerful Cat 5 hurricane, if only briefly--SEEMED to have favorable conditions for maintaining her intensity unti landfall. Yet she didn't.

Yes, hurricanes go through various life cycles. And I understand that it is difficult for hurricanes to maintain such extreme wind speeds for extended periods of time. But I found it somewhat peculiar that Emily became disorganized when and how she did. The timing and manner in which she diminished in intensity was rather similar, IMHO, to some other very strong hurricanes as they also approached mainland landfall over the past couple of years.

Also, it seemed rather unusual that the damage reports did not seem to mesh with the reported wind speeds at landfall. And there were times with Emily when IR sat presentation didn't seem to match the NHC's recon reports.

I think, as has been suggested, that the most likely explanation is a lack of understanding regarding how winds mix and function in a hurricane. That's my opinion. Maybe we'll never know. But being a scientist myself, I tend to believe we probably will some day. I hope that day comes sooner rather than later, enabling us to spare lives and, who knows, perhaps even property.

[Andrew92]

There seems to be a tremdous amount of misunderstanding regarding what I meant by "POOF."

When I used the word "POOF" I did not mean it vanished...or it was weak. I merely meant that "POOF" the MONSTER disappeared. Now, that doesn't mean that a category 3 or 4 hurricane is unworthy of respect. I was just pointing out that Emily--an extremely powerful Cat 5 hurricane, if only briefly--SEEMED to have favorable conditions for maintaining her intensity unti landfall. Yet she didn't.

Yes, hurricanes go through various life cycles. And I understand that it is difficult for hurricanes to maintain such extreme wind speeds for extended periods of time. But I found it somewhat peculiar that Emily became disorganized when and how she did. The timing and manner in which she diminished in intensity was rather similar, IMHO, to some other very strong hurricanes as they also approached mainland landfall over the past couple of years.

Also, it seemed rather unusual that the damage reports did not seem to mesh with the reported wind speeds at landfall. And there were times with Emily when IR sat presentation didn't seem to match the NHC's recon reports.

I think, as has been suggested, that the most likely explanation is a lack of understanding regarding how winds mix and function in a hurricane. That's my opinion. Maybe we'll never know. But being a scientist myself, I tend to believe we probably will some day. I hope that day comes sooner rather than later, enabling us to spare lives and, who knows, perhaps even property.

Sorry, but 135 mph is still a monstrous storm in my opinion. It's a Category 4, capable of causing extreme damage.

-Andrew92

[Mac]

There seems to be a tremdous amount of misunderstanding regarding what I meant by "POOF."

When I used the word "POOF" I did not mean it vanished...or it was weak. I merely meant that "POOF" the MONSTER disappeared. Now, that doesn't mean that a category 3 or 4 hurricane is unworthy of respect. I was just pointing out that Emily--an extremely powerful Cat 5 hurricane, if only briefly--SEEMED to have favorable conditions for maintaining her intensity unti landfall. Yet she didn't.

Yes, hurricanes go through various life cycles. And I understand that it is difficult for hurricanes to maintain such extreme wind speeds for extended periods of time. But I found it somewhat peculiar that Emily became disorganized when and how she did. The timing and manner in which she diminished in intensity was rather similar, IMHO, to some other very strong hurricanes as they also approached mainland landfall over the past couple of years.

Also, it seemed rather unusual that the damage reports did not seem to mesh with the reported wind speeds at landfall. And there were times with Emily when IR sat presentation didn't seem to match the NHC's recon reports.

I think, as has been suggested, that the most likely explanation is a lack of understanding regarding how winds mix and function in a hurricane. That's my opinion. Maybe we'll never know. But being a scientist myself, I tend to believe we probably will some day. I hope that day comes sooner rather than later, enabling us to spare lives and, who knows, perhaps even property.

Sorry, but 135 mph is still a monstrous storm in my opinion. It's a Category 4, capable of causing extreme damage.

-Andrew92

Okay. So why hasn't the reported damage been consistent with 135 mph winds?

[SouthernWx]

I was just pointing out that Emily--an extremely powerful Cat 5 hurricane, if only briefly--SEEMED to have favorable conditions for maintaining her intensity unti landfall. Yet she didn't.

Friend, I never saw any evidence that Emily was of category 5 intensity. The lowest pressure of 929 mb is representative of a 130-135 kt cat-4.....the peak 700 mb winds were in the 151-153 kt range, which normally equates to roughly 135-138 kt at the surface....but as meteorologist Derek Orrt has pointed out, this hurricane has thusfar had surface winds on the order of 85% of flight level not 90%....meaning 153 kt @ 700 mb = 131 kt at the surface.

Even IF you give the 90% ratio to 153 kt @ 700 mb (and 138 kt surface)....you still fall short of cat-5 intensity. While the Saffir-Simpson scale may say "sustained winds of 136 kt or more" constitutes a cat-5, we know NHC doesn't release advisories stating sustained winds of 158 mph...it's either a strong 135 kt cat-4 OR a 140 kt cat-5. Neither I nor most other hurricane experts would assess a hurricane as cat-5 UNLESS flight level winds were at least 155 kt (and 140 kt at the surface).

Also, Emily DID NOT seem to have conditions to maintain 130-135 kt sustained winds to Yucatan landfall. Both SHIPS and GFDL consistently WEAKENED Emily after the hurricane passed south of Jamaica....weakened the hurricane in an area where they normally intensify. The models were correct.....Emily did weaken. Even though flight level winds were 142 kts an hour before landfall, the central pressure was up to 955 mb...more indicative of a 110 kt cat-3 (which was IMO the true intensity of Emily near Cozumel).

Each and every hurricane you want to bring up as going "poof" (weakening) has a very valid reason as to WHY they did so. With Opal it was a combination of 1) inner eyewall collapse, 2) increasing vertical shear and 3) near shore sst and TCHP far below what is needed to maintain a cat-4/5 hurricane. Ivan also moved over an area with low TCHP....why it weakened dramatically the final 10 hours before landfall. Believe me friend, if TCHP had been high enough....both Ivan and Dennis would have been landfalling cat-4's...and possibly Opal as well.

PW

[Normandy]

Even though flight level winds were 142 kts an hour before landfall, the central pressure was up to 955 mb...more indicative of a 110 kt cat-3 (which was IMO the true intensity of Emily near Cozumel).

So even with 142 kt FL winds, you would reduce that to 110 kts at the surface?? thats a fairly big reduction.

[SouthernWx]

Even though flight level winds were 142 kts an hour before landfall, the central pressure was up to 955 mb...more indicative of a 110 kt cat-3 (which was IMO the true intensity of Emily near Cozumel).

So even with 142 kt FL winds, you would reduce that to 110 kts at the surface?? thats a fairly big reduction.

That could have been from a maverick convective burst and not representative of the true intensity....it occurred about the time of diurnal max. I also saw a 124 kt flight level wind in the same NE eyewall only 1-2 hours later. Based on those obs, a steady state central pressure of 955 mb, and the satellite and radar presentation, it's my opinion Emily was weakening at time of landfall with sustained winds of 125-130 mph (110 kt)...a strong cat-3 and not cat-4. That would also explain 1) lack of cat-4 damage and 2) why Emily was so weak after emerging into the southern GOM.

PW

[Normandy]

Even though flight level winds were 142 kts an hour before landfall, the central pressure was up to 955 mb...more indicative of a 110 kt cat-3 (which was IMO the true intensity of Emily near Cozumel).

So even with 142 kt FL winds, you would reduce that to 110 kts at the surface?? thats a fairly big reduction.

That could have been from a maverick convective burst and not representative of the true intensity....it occurred about the time of diurnal max. I also saw a 124 kt flight level wind in the same NE eyewall only 1-2 hours later. Based on those obs, a steady state central pressure of 955 mb, and the satellite and radar presentation, it's my opinion Emily was weakening at time of landfall with sustained winds of 125-130 mph (110 kt)...a strong cat-3 and not cat-4. That would also explain 1) lack of cat-4 damage and 2) why Emily was so weak after emerging into the southern GOM.

PW

I see....i think they were higher because there were lots of deep convective bursts....so there were prolly streaks of cat4 winds here and there mixed in with the cat3 sustained....but yea i agree with ur analysis mostly.

[Matt-hurricanewatcher]

A quastion...Emily in Dennis where both small powerful hurricanes. Dennis moved over Cuba for a better part of a day. In still had a compact inner core. While Emily moved over the Yuactan for about 6 hours in totally unwraps/losses its central/inner core. Emily must of been alot less oreganized then Dennis by far by this.

[docjoe]

I for one would like to thank Mac for this post. I have found it to be quite interesting although the way some have responded is sad. Even if you didnt agree with how it was worded it seemed very clear the intent and meaning of his post. I would like to know more about this as well. I was in Ivan and Dennis and had very similar amounts of damage. This in spite of being about 35 miles from land fall ( as the crow flies) from Ivan and having the eye of Dennis pass over my house.Both storms were approximately 120 MPH at landfall. Also we had more damage from Ivan where I am than some places closer to the eye. I would love to know more about how the land/sea interaction with the winds translates to damage at ground level.

docjoe
if this helps here is a link to HRD that probably relates to this topic
http://www.aoml.noaa.gov/hrd/project200 ... dfall.html

[CSickinFL]

I am a "lurker" who never posts but I had to add my two cents to this thread. Mac I am sorry you have been getting bashed for what IMHO was an insightful and intelligent post. I live in Navarre, approximately 5 miles east of where the center of Dennis' eye passed over. For a variety of personal reasons (not financial) our family did not evacuate for this one. (We did for Ivan) By the time we realized that Dennis was in fact coming RIGHT HERE, it was too late to leave. Between the hours of 3 AM and 2 PM Sunday, I was literally nauseous with fear, based on the somber and frightening info we were recieving from the local TV station, the Weather Channel, the NHC website, and this board. At 4 AM we had "EXTREMELY DANGEROUS DENNIS" coming at us with 145 mph winds. At 10 AM Dangerous Dennis had weakened slightly to 140 mph. At Noon, Dennis was "only" 135 mph. At 2 PM, we lost power, but I would later learn that Dennis made landfall as a Catagory 3 Hurricane, and that "Navarre Beach reported sustained winds of 99 mph with gusts to 121 Mph near landfall."
As I said, I live appoximately 5 miles East of where the eye passed over. My neighbors watched the eye pass over, from the vantage point of their front porch, where they spent the entire storm! ( I personally was huddled in my bathroom with my husband, three kids, and two dogs, praying not to die.) Here is the damage we recieved from Dennis: We lost a few shingles, and one section of our privacy fence fell over. That's it. I was in the north east quadrant of a landfalling Cat 3 hurricane, 5 miles from the eye, one block inland from the Santa Rosa Sound, and that is the complete extent of the damage we received. I personally am grateful, thankful, and extremely contrite that despite making a very bad decision (to stay) and risking my children's lives, we were very, very fortunate that nothing happened to us or our home. It was terrifying to realize that by deciding not to leave, I had put my children directly in harms way. I won't ever take that risk again. However, I can tell you that 99% of the people I have spoken to (who stayed) feel exactly the opposite. "See! Nothing happened. That was a Cat 3, and we didn't even have damage. Now we know we don't have to evacuate for the next one." Many of them are feeling smug that they avoided the hassle, inconvenience, and expense of evacuating, and "nothing bad happened!" I believe that this is exactly the attitude that Mac is concerned about, and was referring to. When the media has everyone thinking that we are all going to be wiped from the earth, and then.... the bad, scary things don't materialize, there are those ( I am NOT including myself in this category, learned my lesson, thanks) who will assume that bad, scary things won't EVER happen to them. This is something to be rightfully concerned about.

[beachbum_al]

Ask those in Gulf Shores and Orange Beach if Ivan fizzle out. I am sure they will say no!

[beachbum_al]

About the word Poof! I don't think you meant it the way that some of us took including myself. Some of us were hit hard by Ivan, Dennis, and I am assuming Emily. Even though Ivan might had weakened he did havoc on the Alabama and Florida Coast. It is still a mess even though they have come a long way since Sept. And then there was Dennis. Dennis might now had done a long range of damage like Ivan did but the area that were hit by Dennis were hit hard. And they were still recovering from Ivan. I guess some of us including myself are just a little touchy and don't mean to jump on your back but the word poof just pushed us a little over poof marker. Okay...I will be quiet now!