Category 5 Monsters

[CentralFlGal]

Something I ran across while organizing my bookmarks and didn't see here after a few searches:

To qualify as a Category 5 hurricane on the Saffir-Simpson hurricane intensity scale, maximum sustained winds must exceed 155 mph (135 kt). Through 1998, only twenty-two Atlantic storms have reached this intensity, and only eight were of category 5 strength at time of landfall. Of these 22, only two made U.S. landfall: the 1935 Florida Keys hurricane and Hurricane Camille, which hit the Mississippi coastline in 1969. The table below lists all known category 5 Atlantic hurricanes since records began in 1886.

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List of Category 5 Atlantic Hurricanes
(1886 - Present)

[See URL below quoted text for easier list-viewing format]

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Interesting Facts

Note that several infamous storms which struck the U.S. are listed in the table above, but no entry appears in the "Landfall" column. This is because the storms had weakened to below Category 5 intensity at the time of U.S. landfall. Hurricanes which had reached Category 5 intensity but had weakened by the time of U.S. landfall include: hurricanes of 1928, 1938 (New England Hurricane), and 1947, plus Donna (1960), Ethel (1960), Carla (1961), Beulah (1967), David (1979), Allen (1980), Hugo (1989), and Mitch (1998). Though it was an extremely strong Category 4 storm, even at landfall, Hurricane Andrew never achieved Category 5 status.

Most Intense At U.S Landfall: 1935 Florida Keys 892 mb/ 26.35 in/ 140 kt

Highest Winds at U.S. Landfall: 1969 Camille 909 mb/ 26.84 in/ 165 kt

Most Intense Atlantic Hurricane: 1988 Gilbert 888 mb/ 26.22 in/ 160 kt

Longest as Category Five:* 1980 Allen 899 mb/ 26.55 in/ 165 kt

* Hurricane Allen reached Category 5 intensity three times along its path through the southern Caribbean and Gulf of Mexico: twice these periods were of 24-hours duration and the third lasted 18 hours.

1) With the exception of Camille, no Category 5 hurricanes have ever existed north of 30 degrees N nor south of 14 degrees N.
2) Four oceanic areas have experienced Category 5 intensity hurricanes twice: (26.5N, 77W), (18N, 86W),(24.5N, 96.5W) and (28-30N, 89W) (the path of Camille)!
3) Areas which have never experienced a landfalling hurricane of Category 5 intensity include: the U.S. East Coast, Cuba, Jamaica, nor most of the Windward or Leeward Islands!

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NCDC / Satellite Gallery / Educational Topics / Category 5 Monsters / SAA / Search NCDC

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http://www.ncdc.noaa.gov/oa/satellite/satelliteseye/educational/cat5hur.html

[feederband]

I thought they promoted Andrew to a 5

[CentralFlGal]

You're right:

Summary:

Hurricane Andrew of 1992 caused unprecedented economic devastation along its path through the Bahamas, southeastern Florida, and Louisiana. Damage in the United States was estimated to be about $26 billion, making Andrew the most expensive natural disaster in U.S. history. This hurricane struck southern Dade County, Florida, with an intensity assessed back in 1992 as a Category 4 on the Saffir-Simpson Hurricane Scale, based upon estimated maximum sustained surface winds of 145 mph. Because of a better scientific understanding of the structure of the windfield in the violent eyewall of strong hurricanes, the intensity of Andrew has now been revised upward for five days during its track across the Atlantic Ocean and Gulf of Mexico. Hurricane Andrew of 1992 is now assessed to be a Category 5 - the highest intensity scale possible - at its landfall in southeastern Florida with peak sustained winds of 165 mph. This makes Hurricane Andrew only the third Saffir-Simpson Scale Category 5 hurricane to impact the United States since at least 1900. Documentation for why and how these changes were made are provided in the writeup below.

Chris Landsea
NOAA Hurricane Research Division
October 2002

http://www.aoml.noaa.gov/hrd/hurdat/andrew.html

Cat 5 at landfall; should be on that list.

[Steve]

Gilbert = the only hurricane that's ever scared the *%() out of me.

Steve

[Swimdude]

I could've sworn Hugo was a cat. 5 at landfall... Or maybe I just need to check on my hurricane knowledge.

[SouthernWx]

I thought they promoted Andrew to a 5

They have....that site hasn't been updated in quite a while. It doesn't list Isabel (2003) or Ivan (2004).

I'm also personally very suspicious about some of the hurricanes on that list....especially before 1980. For example, the 1947 hurricane was indeed a very large, intense hurricane....but the lowest central pressure I've ever found for it was about 939 mb as it crossed Grand Bahama Island. A hurricane with such a large core would IMO be 120 kt or so. Hurricane Carla in 1961 is listed as cat-5, and there was no evidence sustained winds were that strong; the only 175 mph wind I'm aware of was a peak gust of 175 measured at Port Lavaca (I've seen other reports it was an estimate after the anemometer failed at 170 mph).
In either case, considering the size and central pressure, Carla's true intensity was likely 145 mph or so...cat-4. On the other hand, in September 1966, recon aircraft measured 927 mb and 198 mph winds in small violent hurricane Inez...at 8090' flight level. Inez isn't listed as a category 5, although flight level winds indicate surface winds were close to Andrew's (175-180 mph).


Unfortunately, in the days before 1970, U.S. military crews were sometimes notoriously off target with their wind speed estimates.....sometimes 30 kts too high or low. I see one 1950's era hurricane ("Dog") listed at 160 kt (185 mph)...but have never found a measured central pressure report anywhere close to cat-5 intensity, so I'm highly suspicious it was as intense as Gilbert and Camille (esp since it was several hundred miles NORTH of Puerto Rico). In 1960, Ethel is credited with 160 mph sustained winds....but that was based solely on an experimental buoy report I've never believed was accurate....there's NO WAY a hurricane could intensify then weaken so rapidly (from cat-1 to cat-5 then back to cat-2 in six hours.....no way!).

Also, I know those wind speed reports for David (1979) and Anita (1977) were 700 mb flight level winds...maxed out at 156 kt for David south of Puerto Rico and 150 kt at flight level for Anita just before landfall in NE Mexico. It's more like surface winds of 160 mph for David and 155 mph for Anita, not 175 mph for both as listed on that site.

There are hurricanes on that list that IMO don't belong....and others that should be there but aren't (Inez; Sept 1944; Nov 1932; etc).

PW

[Steve]

Hugo twas a 4, eh?

Steve

[CentralFlGal]

Steve:

Digitized Charleston WSR-57 radar image of Hugo with superimposed winds Note strongest winds well east of Charleston near Bulls Bay This area experienced Category 4 Hurricane conditions Charleston only experienced Category 2 Hurricane conditions Regardless, $9 billion damage done by Hugo on South Carolina coast

http://www.photolib.noaa.gov/historic/nws/nwind9.htm

Hope that helps!

SouthernWx:

Thanks for your insight! It's much appreciated and something to digest as we look at the data.

[SouthernWx]

Hugo twas a 4, eh?

Steve

At landfall along the South Carolina coast, Hugo was at cat-4 intensity. Based on 700 mb flight level winds of 140 kt (161 mph), storm surge height, and observed damage....it's likely surface sustained winds were 145 mph or so.

The only time in Hugo's life that it attained cat-5 status was for about six hours when the hurricane was well east of the Lesser Antilles (near 14 N/ 54.5 W), when the first NOAA aircraft mission found 918 mb and 160 kt at flight level, meaning a likely surface sustained wind around 160-165 mph. At this time, Hugo was a small and extremely intense hurricane....with 64 kt winds only extending 30 mi from the center. This was also the NOAA research mission that almost didn't come back (the last flight for Dr Jeffrey Masters).....when the plane was badly damaged (by extreme shear; lost all electronics and suffered some structural damage).

Thankfully, another NOAA research plane and a USAF WC-130 were nearby and able to assist the crippled P-3 aircraft out of the hurricane, and guide it back to Puerto Rico.

Hugo changed from a small, violent cat-5 to large, sprawling cat-4 before impacting land....cat-4 intensity is what it impacted Guadeloupe, St Croix, and South Carolina at (and a strong cat-3 landfall for Puerto Rico).

PW

[weatherluvr]

Seems like that page hasn't been updated in quite some time.