User:PolitiCalypso/MajorHurricanes

Introduction
This page contains a compilation of verifiable facts and my own opinions about major Atlantic hurricanes (Category 3+). It is not intended to be comprehensive. It is organized loosely and contains information and speculation that I find interesting, and that's the sole criterion for inclusion.

The 800 Club: Members
These hurricanes had confirmed pressure readings of under 900 hPa (mb).

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Hurricane Wilma
Wilma, the 4th Category 5 hurricane of 2005, rapidly intensified on the night of October 19 to become the most intense Atlantic hurricane recorded. Its pressure dropped precipitously from 946 mb at 8:00 pm EDT to 901 mb by 2:00 am EDT, then to a record value of 882 mb by early morning. It may have dipped lower than this briefly; reconnaissance did not have any planes in the storm from approximately 6:00 am till 9:00 am EDT.







Hurricane Gilbert
Gilbert achieved Category 5 intensity on September 13, 1988, rapidly intensifying from a 934 mb Category 4 storm to an 888 mb Category 5 in twelve hours. At the time, this was a record for intensity for the Atlantic, but it was broken by Wilma in 2005. Gilbert and Wilma both had extremely small "pinhole" eyes that likely contributed to their rapid deepening and extreme intensity.







Labor Day Hurricane
The Labor Day Hurricane of 1935 was a Category 5 storm that intensified from a tropical storm to an 892 mb Category 5 storm in a matter of 48 hours. It struck the Florida Keys at full force, decimating the islands and killing hundreds. The storm had a confirmed pressure of 892 mb and might have been lower; an unconfirmed reading of 880 mb was reported. The storm has many different wind speeds given in literature, from the current best track estimate of 160 mph to up to 200 mph. A NOAA PowerPoint publication by researchers Jamese Sims and David Glenn proposes making an official change of 185 mph to the best track, and it'll probably be adopted for the 2005 best track revision.







Hurricane Rita
Rita was the third Category 5 storm of 2005. Like the others in this list, it rapidly intensified to Category 5 status, then to sub-900 mb status. Its measurement of 895 millibars made it the most intense storm observed in the Gulf of Mexico (although I suspect Camille may have actually beaten or tied it--see below). The storm made landfall on the Texas/Louisiana border as a Category 3 hurricane.







Hurricane Allen
Allen was a long-lived Cape Verde hurricane that achieved Category 5 intensity three separate times in the 1980 hurricane season and briefly reached 899 mb. Despite the fact that its path took it through the Caribbean, it did not technically make landfall until it struck Texas as a low-end Category 3 storm. Until Hurricane Emily took the title from it in 2005, it reached Category 5 intensity earlier in the year than any other storm.




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The 800 Club: Suspects
These storms were close runners-up.

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Hurricane Katrina?
Hurricane Katrina's minimum pressure was recorded at 902 mb on August 28, 2005. This is almost certainly the lowest that the storm achieved, because Hurricane Hunter aircraft were in the storm during the whole of its most intense phase. If it'd dropped below 900 mb, they would have caught it. Verdict: Not in the 800 Club.







Hurricane Mitch?
Hurricane Mitch's minimum pressure was recorded at 905 mb. For similar reasons as with Katrina, Mitch almost certainly did not dip below 900 mb. In fact, airplane reconnaissance did intensive studies into the "wind profile" of Mitch, which was rather unusual. They found that the usual ratio of flight-level winds to surface-level winds did not apply with Mitch, and had they applied it, they would have estimated its wind speeds considerably lower than they actually were. Verdict: Not in the 800 Club.







Hurricane Camille?
Hurricane Camille's minimum pressure was recorded at 905 mb, along with an estimate of 190 mph surface wind speeds (made by recon). However, there were no further pressure measurements until the storm made landfall, at which time its pressure was 909 mb. The time between the reported minimum pressure and the landfall was 24 hours, almost certainly not long enough for it to weaken due to an eyewall cycle and then reintensify to its former intensity. Given the fact that intense storms such as Ivan, Dennis, Katrina, and Rita all weakened immediately prior to landfall, it is quite possible that the 905 mb was not Camille's lowest pressure. There is usually a pool of cooler water off this stretch of the Gulf Coast that contributes to the weakening of hurricanes, and it's clear that it at least knocked off 4 mb from Camille. I rather suspect it weakened it more than that, and that while the reconnaissance aircraft were absent from the storm, it intensified below 900 mb, so that its interaction with this pool of water did not drop it below Category 5. Verdict: Maybe!




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The (Probably) Seriously Overestimated
These storms were, in my nonprofessional opinion, overestimated in terms of wind speed. I would not be surprised if NOAA's ongoing Reanalysis Project downgrades some of them when it reaches them.

Hurricane Dog (1950)


This pre-satellite hurricane had no pressure readings reported, but the best track estimate shows it reaching 185 mph while heading almost due north in the open Atlantic Ocean, and maintaining that intensity for 12 hours. It also shows the hurricane holding Category 5 status for 2 days and 18 hours, not dropping below it during any time during this period. Considering where it was located and how it was moving, I'd say that this seems unlikely. It probably was a Category 5, but I doubt it had winds higher than 165 or 170 mph. Modern Category 5 hurricanes achieve extreme winds of 175+ mph in the Caribbean and Gulf of Mexico, and modern Category 5s that have stayed in the Atlantic Ocean during their time as a 5 (e.g., Andrew and Isabel) have not reached 180 mph. Also, hurricanes tend not to strengthen to extreme intensities while recurving northward in the Atlantic Ocean.

Hurricane Cleo (1958)
This storm allegedly became Category 5 in the open Atlantic. However, I seriously doubt that this was the case. Here's the best track data for it for which there are pressure readings (note that it includes the observation of Category 5 intensity):

I think that most of these wind speeds are too high, up to (but not including) the reading of 120 mph and 970 mb on the 17th of August. Ordinarily I'd give these pre-satellite era major hurricanes the benefit of a doubt, since usually there are not many consecutive pressure measurements, merely wind estimates. However, the data on this one--if complete--pretty much rule out the possibility that this storm had higher winds than about 145 mph.

Hurricane Ethel
This is the hurricane that, if the data are to be believed, went from an 85-mph Category 1 to a 160-mph Category 5 in 12 hours, back down to a 90-mph Category 1 in 6 hours, then down to a 70-mph tropical storm in another 6 hours... all over open sea (the Gulf of Mexico). Additionally, the sole pressure reading is one of 981 mb from when it had 125 mph winds reported, which itself is more than suspect. Rapid intensification is certainly possible, but such an epic disintegration immediately following it and a highly suspicious pressure record make me skeptical that this hurricane was ever much more than about a Category 2.

Hurricane Allen
I don't doubt that this storm was a Category 5, and it may well have had the 190 mph winds that it is credited with. I'm questioning the wind data from a specific period of time in the hurricane's life cycle:

For every data point here except possibly the reports of 135 mph wind with 955 mb of pressure, I would say that the wind speed is too high. I would downgrade the first three measurements to 155, 150, and 145 mph respectively (Category 4 intensity), downgrade the third from last to 140 mph, the second from last to 145 mph, and the last to 150 mph.

Future content

 * Selected storms that, in my opinion, should not have been downgraded at landfall
 * A list of the top 35 storms in intensity