Camile not as bad as I thought!!!!

[skywarn]

The below link will give you a satellite photo taken of Camille by the earlier Nimbus III satellite 1 day before she made landfall. There are also other photos you can view on some of the damage she left behind.

http://www.nationalgeographic.com/force ... _1_11.html

[Derek Ortt]

MGC,

the pressure did start to rise in the final hours before landfall from 905 to 909mb. What may have bene happening was a classic eye wall replacement cycle. What often happens in these cases is for the winds to decrease significantly, but little pressure change (Floyd only weakened 10mb during an EWRC from 922 to 932mb, yet the winds decreased from 135 to 105KT). Also Gilbert weakened from 888 to 900 right before landfall, yet the winds decreased from 165-140KT. I suspect something very similar was starting to happen with Camielle just due to the increase in pressure

[SouthernWx]

MGC,

the pressure did start to rise in the final hours before landfall from 905 to 909mb.

Derek, that 905 mb reading was taken during the late evening of August 16th, 1969....over 24 hours before landfall.

There were only three eye penetrations made into Camille's eye between western Cuba and landfall at Bay St Louis.....early on the afternoon of August 16th, a C-130 recon plane from Orlando (McCoy AFB) penetrated and found 908 mb/ 26.81". Later that evening, a 905 mb reading was obtained by the same USAF crew.

During the night of August 16th and morning hours of August 17th, no further penetrations of Camille's eye were made....although USN recon planes flew missions on the periphery of Camille's eyewall, reporting the eye diameter less than 8 n mi at times on their radar scopes.

Early on the afternoon of Sunday August 17th, a USAF C-130 penetrated Camille's eyewall and reported a central pressure of 901 mb/ 26.61" and flight level winds of over 180 kts. This was the basis of raising Camille's sustained winds from 160 mph to 190 mph on the late afternoon advisory.
There were plans for the USAF plane to stay in Camille until near time of landfall, but unfortunately on the outbound leg, the plane experienced an engine failure and was forced to limp home on 3 engines, making a successful emergency landing at Houston, Texas.

Upon review of the recon crews calibration, it was determined the actual central pressure around 18z on August 17 was 918 mb/ 27.11" instead of the widely reported 901 mb (in the press). This final central pressure reading was measured about four hours before Camille passed near the Mouth of the Mississippi river, and about 8 1/2 hours before landfall near Bay St Louis, MS.

That's one of the big mysteries of hurricane Camille....was the pressure at 18z on 8/17/69 really 918 mb or 901? If the "official" 918 mb figure was right, then Camille deepened 9 mb between 2 p.m. and 10:30 p.m. (time of landfall); or did the pressure rise near the Mouth of the Mississippi river...then deepen during those final 2-3 hours while traversing the extremely warm shallow waters of Mississippi Sound? We'll never know for sure...

FYI: Also, after witnessing similar extreme intensity hurricanes since Camille (Mitch, Gilbert, Allen, Ivan), I now have considerable confidence that Camille's true peak intensity may have well been near or below 900 mb, at least for a short time. Just imagine if NOAA and USAFR recon had only obtained three central pressure readings from hurricane Gilbert between Grand Cayman and Cozumel....odds are we'd have missed the true minimum value (record breaking 888 mb).

PW

[donsutherland1]

Perry,

You wrote:

Structural engineer Herbert Saffir surveyed the wind damage after hurricane Camille's passage and stated afterwords:

"The wind damage caused by this great hurricane is far worse than any hurricane I've previously surveyed (since 1947); the wind damage is severe over an extensive area both along the coastline and inland. Even inland away from the gulf, structures were splintered....damage consistent with wind speeds of a major tornado" (F3 or higher)

To put this into perspective, here's some information from the Fujita Tornado Damage Scale:

F3: 158-206 mph: "Severe damage. Roofs and some walls torn off well-constructed houses; trains overturned; most trees in forest uprooted; heavy cars lifted off the ground and thrown."

In another post, you mentioned the experience of the planes that had attempted to penetrate Camille's eye. On August 26, 1969, The New York Times reported, "He [Vice President Agnew] said the Government had found that Navy storm-hunting planes had excellent meteorological equipment but were not strong enough to stand up against a hurricane with the 200-mile-an-hour winds of Camille. On the other hand, Mr. Agnew said, the Air Force had more durable planes but lacked advanced scientific weather-finding instruments." Given the accounts of what took place, the limited number of measurements, and difficulty obtaining measurements, the 909 mb reading at landfall and the structural damage are the best measures of Camille's true strength. Arguments that Camille was weakening or strengthening near landfall are speculation given the above constraints.

If one wants a reasonable estimate of Camille's strength, one must go by the credible evidence: structural damage (which you've done a great job describing), barometric reading, and accounts of the experts who were on the scene. Dr. Robert H. Simpson, then director of the National Hurricane Center observed following his inspection of what occurred:

By very conservative measurements, the high water reached a level of 31 feet above high tide marks, and this is 50 percent higher than we ever have measured in any storm before.

We will never know the maximum velocity of the winds, but on the basis of my experience and observations, I would conservatively estimate they ranged at or above 200 miles per hour.

Dr. Simpson was no uninformed novice who wanted to make a wild account of the storm. He was one of the nation's foremost experts whose credibility depended on accuracy based on the facts.

If one is familiar with the Saffir-Simpson scale, one will note that a Category 5 hurricane has a storm surge of 19 feet or more. Camille's storm surge was at least 31 feet. Even if one takes into consideration the affected area's geography, the argument that Camille was at the low-end of a Category 5 storm is not supported by the storm surge that took place.

In the end, if one goes by the evidence, it is very reasonable to presume that Camille had maximum sustained winds of at least 170 mph-180 mph at landfall with gusts of around 200 mph:

• Barometric reading (909 mb)
• Structural damage equivalent to an F3 Tornado
• 31-foot storm surge
• Personal observations of NHC Director Dr. Simpson

In contrast, the case against such strength is very weak:

• Small windfield: Just because a hurricane does not have a large windfield does not mean it is not strong. The Labor Day Hurricane (1935) was also a very compact storm
• The 909 mb reading was above the storm's lowest reading: With the limited number of measurements taken and the difficulties in obtaining them, one simply cannot conclude with any degree of confidence that Camille was weakening or strengthening immediately prior to landfall. One can only know its strength at landfall per the barometric reading at landfall.
• Camille was barely a Category 5 storm at landfall: Structural damage, storm surge, and Dr. Simpson's expert analysis all debunk this hypothesis
• Wind measurements were lacking: Wind instrumentation was damaged or destroyed. The lack of such measurement does not in any way confirm a weaker storm. The structural damage and storm surge reveal that Camille was not a borderline Category 5 storm at landfall but a healthy Category 5 storm.

[donsutherland1]

Perry,

Exactly right. The U.S. Navy's planes were not sufficiently strong to withstand Camille's strength, hence their ability to take many measurements was impaired. The USAF was able to take measurements with stronger planes but the number of reconnaissance missions was limited.

Great point about Hurricane Gilbert.

[vbhoutex]

To put this into perspective, here's some information from the Fujita Tornado Damage Scale:

F3: 158-206 mph: "Severe damage. Roofs and some walls torn off well-constructed houses; trains overturned; most trees in forest uprooted; heavy cars lifted off the ground and thrown."

I saw this type of damage 50-60 miles inland after Camille. It is beyond me how anyone can argue that Camille was not a STRONG CAT5!!!!

Very good analysis Perry and Don!!! It is always nice to have learned people help us put everything in perspective.

[donsutherland1]

For those who are interested, even immediately prior to landfall, Camille was over water with a temperature of 29.5°C-29.75°C, which would help, at a minimum, to allow it to sustain itself:

[vbhoutex]

Looking at that map and knowing the track of Camille tells us one of the reasons Camille was so intense. Looks almost like she followed the warmest areas right to the coast.

[Scorpion]

I think that Camille made landfall with winds around 145-150 knots. It is just too unprecedented for Camille to have made landfall with 165 knot winds at that latitude, plus the fact that the Northern Gulf has been known to weaken most strong hurricanes. The damage was still tremendous however.

[donsutherland1]

Dave,

I absolutely agree with you. To further illustrate Camille's power, the following are some images:

Trinity Church (before):


Trinity Church (after):


Historic home that was to be Episcopal High School (before):


Same building (after):


Large ships driven aground at Gulfport Harbor:


Source of Photos: NOAA Historical Photo Collection

[donsutherland1]

For those who are not entirely familiar with the gradient wind equation, although it might suggest that Camille and Andrew were of similar strength, that's just one plausible scenario among several. When the factor of centrifugal force is incorporated in the equation, one can come up with a number of plausible scenarios. As Perry and I have written earlier, the structural damage, storm surge upon landfall, etc., all suggest greater maximum winds for Camille than for Andrew.

For those who want to learn about the gradient wind equation, even if one isn't very good at calculus, the Plymouth State website offers a good description. The following paragraph from the website highlights the important limitation I described at the beginning of this post:

The gradient wind is very much like the geostrophic wind, in that it is a frictionless wind which allows for flow that is parallel to the height contours. The one difference between the geostrophic wind and the gradient wind is that the gradient wind includes the centrifugal force, thereby allowing curvature in the flow field. At first glance, this may seem to be simply an addition to the geostrophic wind equation, since the two flows are very similar to one another. For example, if the curvature is equal to zero, then geostrophic flow is obviously the result. However, the addition of the centrifugal force complicates the equation tremendously and creates several different solutions to the gradient wind equation.

Consequently, if one must choose between one theoretical outcome among several, given the weight of the actual evidence, one should choose the stronger outcome. Again, if one engages in what is today referred to as "forensic meteorology," the overwhelming evidence points to Camille's greater strength relative to Andrew and her being a solid Category 5 storm at landfall.

[vbhoutex]

Don, those images were etched in my mind forever before I even saw pictures because I traveled along the MS coast(something I had done several times before Camille hit) on Oct. 20, 1969 and saw it first hand. The only word for what I saw is "INDESCRIBABLE". It literally looked like pictures of Hiroshima or Nagasaki after the A-bombs were dropped. It brought my mother and I both to tears.

[vbhoutex]

I think that Camille made landfall with winds around 145-150 knots. It is just too unprecedented for Camille to have made landfall with 165 knot winds at that latitude, plus the fact that the Northern Gulf has been known to weaken most strong hurricanes. The damage was still tremendous however.

What does unprecedented have to do with it?

Evidence I have seen presented suggest otherwise.

[donsutherland1]

Dave,

I agree with your insights from your personal observations. You also raise a great point with regard to what is "unprecedented." If one examines past great hurricanes that hit an area ranging from Louisiana to Alabama, one finds that for Camille to have retained most or all of her strength by landfall would not be "unprecedented" but actually quite consistent with what has occurred in the past.

In general, great hurricanes that have moved onshore at a northwest or north-northwest trajectory and were not turned quickly toward a more easterly trajectory afterward reached shore near or at their maximum strength. This is no fluke. Storms that turned rather quickly or were already heading somewhat east of north had encountered resistance/shear and were turned quickly or had turned.

The following is a list of major hurricanes that made landfall in this region since 1900 and moved onshore at a north-northwest trajectory:

Hurricane #6 (1906): conserved strength
Hurricane #8 (1909): conserved strength
Hurricane #1 (1916): conserved strength
Hurricane #3 (1926): conserved strength
Hurricane Frederic (1979): conserved strength

The following is a list of major hurricanes that made landfall in this region since 1900 and moved onshore with either a relatively quick turn or were heading somewhat east of north at landfall:

Hurricane #5 (1915): weakening
Hurricane Hilda (1964): weakening

In sum, even the historical experience argues that given Camille's path onshore and her only gradual turn once well inland, she was very likely close to her maximum strength at landfall. Combined with the evidence noted earlier in this thread, the case for her being a solid Category 5 hurricane at landfall is overwhelming.

[dhweather]

I think that Camille made landfall with winds around 145-150 knots. It is just too unprecedented for Camille to have made landfall with 165 knot winds at that latitude, plus the fact that the Northern Gulf has been known to weaken most strong hurricanes. The damage was still tremendous however.

What does unprecedented have to do with it?

Evidence I have seen presented suggest otherwise.

I can assure you that precedence did not matter for Camille.
When you look at photos that different folks down here have, listen to
first hand accounts of damage and riding it out, look at marks where the
storm surge actually was - there is no doubt in my mind that 165kt winds
were here - there was just no instrumentation to keep up with them.

Don has done an exceptional job making the case that Camille still
ranks as the strongest, most destructive hurricane to ever make
landfall in the US.

[donsutherland1]

Thanks, Dhweather. I believe Perry (Southernwx) deserves a lot of credit, as well. I'm really quite suprised by the controversy given the strength of evidence in favor of Camille's strength at landfall.

[dhweather]

You are right Don - Perry also made significant input into this as well.

Kudos to both of you!

[MGC]

Does anyone have a link or radar picture of Camille near landfall? It would put to rest the agument that Camille was undergoing an eyewall replacement cycle. I have read conflicting reports some saying Camille had a tight 8 mile wide eye while others claim Camille had a double eye, typical of a replacement......MGC

[SouthernWx]

Does anyone have a link or radar picture of Camille near landfall? It would put to rest the agument that Camille was undergoing an eyewall replacement cycle. I have read conflicting reports some saying Camille had a tight 8 mile wide eye while others claim Camille had a double eye, typical of a replacement......MGC

At time of landfall, both NWS radars at New Orleans and Jackson indicated a perfectly symmetrical eye....only 11 statute miles in diameter. I've seen no evidence of either an eyewall replacement or concentric eyewall structure.

***If an eyewall replacement occurred, IMO it occurred earlier in the day (Sunday Aug 17) while Camille was still approaching the Mouth of the Mississippi. Both visible satellite and recon data early that Sunday afternoon indicated this....with a less distinct eye on satellite, and the central pressure of 918 mb/27.11".
It's entirely possible (IMO probable) the eyewall replacement cycle ended shortly after recon took the reading...and began to intensify again before landfall.

The set point (lowest possible central pressure) was likely around 895-900 mb....based on hurricane Allen in the same area (SE GOM) in August 1980. It's reasonable to assume Camille bottomed out near 900 mb (after the 905 mb recon report late on Aug 16th), then underwent eyewall replacement early on August 17th....with pressure rising to near 920 mb by early afternoon when recon took the final reading before landfall -- with additional deepening before landfall (but not back to 900 mb due to interaction with the Mississippi river delta).

We don't know with 100% certainty the "official" central pressure at landfall was 909 mb. The reading of 26.85"/ 909.3 mb was reported by a private citizen located near the west end of the Bay St Louis bridge. In a hurricane possessing such an intense and small eyewall...the pressure gradient in the eye was tremendous. If the weather observer was only 1 statute mile from the true pressure center, the true lowest central pressure could have been several millibars lower.

PW

[donsutherland1]

The top image is Camille's eye near landfall (Jackson, MS radar). The bottom image is Camille's eye after she was well inland (New Orleans radar):

[img]ftp://ftp.nhc.noaa.gov/pub/storm_archives/atlantic/prelimat/atl1969/camille/prelim04.gif[/img]

Even though the images are small, it is quite apparent that Camille had a very tight eye prior to landfall and not a double-eye structure.