List of Category 5 Pacific hurricanes

Category 5 hurricanes are tropical cyclones that reach Category 5 intensity on the Saffir-Simpson Hurricane Scale. They are the most catastrophic hurricanes that can form. They are rare in the eastern Pacific Ocean and generally form only once every several years. In general, Category 5's form in clusters in single years. Landfalls by such storms are rare due to the generally westerly path of tropical cyclones in the northern hemisphere.

The term "hurricane" is used for tropical cyclones in the Pacific Ocean, north of the equator and east of the international date line. A Category 5 Pacific hurricane is therefore a tropical cyclone in the north Pacific Ocean that reached Category 5 intensity east of the international dateline. Identical phenomena in the north Pacific Ocean west of the dateline are called "typhoons" or "super typhoons". Category 5 super typhoons generally happen several times per season, so cyclones of that intensity are not exceptional for that region. This difference in terminology therefore excludes storms such as Super Typhoon Paka, which formed east of the dateline but did not reach Category 5 intensity until after crossing the dateline.

tatistics

A Category 5 hurricane sustained winds of greater than convert|135|kn|mph km/h|1|lk=on.cite web|url=http://www.nhc.noaa.gov/aboutsshs.shtml|publisher=National Hurricane Center|date=2007-08-17|accessdate=2008-09-14|title=The Saffir-Simpson Hurricane Scale] Sustained winds refers to a one-minute average measured convert|10|m|ftin|1|lk=on above the ground. Short gusts can be up to 50% higher than the sustained winds.cite web|url=http://www.aoml.noaa.gov/hrd/tcfaq/D4.html|publisher=Atlantic Oceanographic and Meteorological Laboratory Hurricane Research Division|work=FAQ: Hurricane, Typhoons, and Tropical Cyclones|author=Chris Landsea|accessdate=2006-01-04|title=Subject: D4) What does "maximum sustained wind" mean ? How does it relate to gusts in tropical cyclones?] As a tropical cyclone is moving, its wind field is asymmetric. In the northern hemisphere, the strongest winds are on the right side of the storm (relative to the direction of motion). The highest winds given in advisories are those from the right side.cite web|title=Subject: D4) What does "maximum sustained wind" mean ? How does it relate to gusts in tropical cyclones?|url=http://www.aoml.noaa.gov/hrd/tcfaq/D6.html|publisher=Atlantic Oceanographic and Meteorological Laboratory Hurricane Research Division|work=FAQ: Hurricane, Typhoons, and Tropical Cyclones|author=Chris Landsea|accessdate=2006-01-04]

Between the 1959 and 2006 seasons inclusive, only 12 hurricanes have reached and were recorded as a Category 5. There are no known Category 5 storms occurring before 1959. It is possible that some earlier storms reached Category 5 over open waters, but the strongest winds were not measured.cite web|publisher=National Hurricane Center|title=Eastern North Pacific Tracks File 1949-2007|accessdate=2008-09-14|url=http://www.nhc.noaa.gov/tracks1949to2007_epa.txt|format=plaintext|date=2008-03-21]

Lists of Category 5 Pacific hurricanes

Listed in chronological order

This lists all of the Category 5 hurricanes in the order in which they formed. Only 1994's Hurricane Emilia and 2006's Hurricane Ioke have reached Category 5 intensity more than once; that is, by weakening into a Category 4 or weaker storm and then re-strengthening.

Before the advent of reliable geostationary satellite coverage in 1966, the number of eastern Pacific tropical cyclones was significantly underestimated.cite web|url=http://www.aoml.noaa.gov/hrd/tcfaq/E10.html|publisher=Atlantic Oceanographic and Meteorological Laboratory Hurricane Research Division|work=FAQ: Hurricane, Typhoons, and Tropical Cyclones|author=Chris Landsea|accessdate=2006-01-04|date=2002-06-11|title=Subject: E10) What are the average, most, and least tropical cyclones occurring in each basin?] It is therefore possible that there are Category 5's other than those listed, but they were not reported and therefore not recognized. However, the lack of Category 5's during the late 1970s, 1980s, and early 1990s, is certain.

The minimum central pressure of these storms is, for the most part, estimated from satellite imagery using the Dvorak technique. In the case of Kennacite web|url=http://www.nhc.noaa.gov/2002kenna.shtml|title=Tropical Cyclone Report Hurricane Kenna|date=2002-12-26|accessdate=2008-09-14|author=James Franklin|publisher=National Hurricane Center] and Ava,cite web|url=http://www.photolib.noaa.gov/htmls/wea01151.htm|work=NOAA Photo Library|accessdate=2008-09-14|author=F.J. Hoelzl|date=1973-06-06|publisher=National Oceanic and Atmospheric Administration|title=wea01151, NOAA's National Weather Service (NWS) Collection] the central pressure was measured by hurricane hunter aircraft flying into the storm. In the case of the 1959 Mexico hurricane, the best central pressure reading was measured after landfall. Because of the estimation of central pressures, it is possible that other storms more intense than these have formed.cite web|url=http://www.nhc.noaa.gov/1997guillerm.html|title=Preliminary Report Hurricane Guillermo|date=1997-10-02|publisher=National Hurricane Center|accessdate=2008-09-16|author=Max Mayfield]

The reason for estimating the pressure is the fact that most of these storms did not threaten land.cite web|url=http://www.aoml.noaa.gov/hrd/tcfaq/H2.html|publisher=Atlantic Oceanographic and Meteorological Laboratory Hurricane Research Division|work=FAQ: Hurricane, Typhoons, and Tropical Cyclones|author=Neal Dorst|accessdate=2006-01-04|title=Subject: H2) Who are the "Hurricane Hunters" and what are they looking for?] As Kenna was threatening land, its pressure was measured by a dropsonde. Hurricane Ava never threatened land. However, it was flown into to test equipment and conduct research.

Before 1997, the means for estimate pressure from satellite imagery was not available. Older storms have incomplete pressure readings taken by ships, land-based observations, or recon aircraft. Ava's minimum known pressure was measured when it was a Category 4, for example. John and Gilma have incomplete pressures because the Central Pacific Hurricane Center, in general, did not publish pressure on systems in the central Pacific (140°W to the dateline) at the time.cite web|url=http://www.nhc.noaa.gov/archive/storm_wallets/epacific/ep1989-prelim/dalilia/prelim03.gif|title=Preliminary Report Hurricane Dalilia|publisher=National Hurricane Center|accessdate=2006-01-04|date=1989-08-30|author=Jim Gross|format=GIF|page=3]

Note that this list is not identical to the list of most intense Pacific hurricanes. The most intense known Category 4 storm in the eastern Pacific was 2001's Hurricane Juliette. Juliette's lowest pressure was 923 millibars.

Climatology

In the eastern Pacific, Category 5 hurricanes usually occur only in El Niño years. During El Niño years, conditions are more favorable for tropical cyclones because of warmer sea surface temperatures and reduced wind shear. This is why Category 5's cluster in single seasons. The effects of El Niño are most significant in the central Pacific (140°W to the dateline).cite web|url=http://www.aoml.noaa.gov/hrd/tcfaq/G2.html|publisher=Atlantic Oceanographic and Meteorological Laboratory Hurricane Research Division|work=FAQ: Hurricane, Typhoons, and Tropical Cyclones|author=Chris Landsea|accessdate=2006-01-04|title=Subject: G2) How does El Niño-Southern Oscillation affect tropical cyclone activity around the globe?]

The general lack of Category 5's in non warm-ENSO years is because of there being limited space for development. The prevailing ocean currents of the area carry warm water to the west. As there is no large piece of land to block the water and cause it to "pile up" like in the Atlantic, the area suitable for all tropical cyclones is small. Farther out to sea, while waters are still warm, wind shear limits the development of tropical cyclones in the waters south of Hawaii. This makes an otherwise ideal region unfavourable for tropical cyclones.

This does not mean that a Category 5 cannot form outside of an El Niño event. The entire year of 1959 was neither an El Niño or a La Niña, but had two Category 5's and was the deadliest pacific hurricane season ever recorded in history. Most of 1973 was during a La Niña, which reduces tropical cyclone activity in the eastern Pacific.cite web|url=http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml|publisher=Climate Prediction Center|title=Cold and Warm Episodes by Season|accessdate=2006-01-04]

Landfalls

Of all of the Category 5 Pacific hurricanes, the only ones to make landfall were the 1959 Mexico hurricane and Hurricane Kenna. The 1959 storm was the only one to make landfall as a Category 5, as Kenna had weakened to a Category 4 at the time of its landfall. These are the strongest and third strongest landfalls by east Pacific tropical cyclones, respectively—the second strongest was 1976's Hurricane Madeline.

In addition to those two systems, Hurricanes John, Linda and Ioke all threatened land for a while. John had minimal impact on Johnston Atoll and caused heavy surf in Hawaii. Linda was briefly forecast to approach southern California, and it passed close to Socorro Island near peak intensity.cite web|url=http://www.nhc.noaa.gov/1997linda.html|title=Preliminary Report Hurricane Linda|date=1997-10-25|author=Max Mayfield|accessdate=2006-01-04|publisher=National Hurricane Center] Ioke had minor effects on Johnston Atoll as well.

The reason for the lack of landfalls is that tropical cyclones in the northern hemisphere usually travel to the west.cite web|url=http://www.aoml.noaa.gov/hrd/tcfaq/G8.html|author=Chris Landsea|accessdate=2008-09-14|work=FAQ: Hurricane, Typhoons, and Tropical Cyclones|publisher=Atlantic Oceanographic and Meteorological Laboratory Hurricane Research Division|title=Subject: G8) Why do hurricanes hit the East coast of the U.S., but never the West coast?] In the Atlantic, this sends hurricanes towards North America. In the eastern Pacific, this sends tropical cyclones out into the open ocean to dissipate over waters too cool to support them or in environments with high wind shear. Hawaii, the only heavily populated island chain in the eastern Pacific, is protected from most hurricanes by a subtropical ridge and is small enough to avoid being hit simply due to low odds.

ee also

* List of tropical cyclones
* List of Pacific hurricane seasons
* List of Category 5 Atlantic hurricanes

Notes

References

* [http://www.weather.unisys.com/hurricane/e_pacific/index.html Unisys Archive] accessed January 4, 2006
* [http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml NOAA cold and warm ENSO episodes] accessed January 4, 2006
* [http://www.prh.noaa.gov/cphc/summaries/1959.php CPHC 1959 Summary] accessed January 4, 2006
* [http://www.prh.noaa.gov/cphc/summaries/1994.php CPHC 1994 Summary] accessed January 4, 2006
* [ftp://ftp.nhc.noaa.gov/pub/storm_archives/pacific/prelimep/ep1994/gilma/ NHC Gilma Summary] accessed January 4, 2006
* [ftp://ftp.nhc.noaa.gov/pub/storm_archives/pacific/prelimep/ep1994/john/ NHC John Summary] accessed January 4, 2006
* [http://www.nhc.noaa.gov/1997guillerm.html NHC Guillermo Report] accessed January 4, 2006
* [http://www.nhc.noaa.gov/1997linda.html NHC Linda Report] accessed January 4, 2006
* [http://www.nhc.noaa.gov/2002elida.shtml NHC Elida Report] accessed January 4, 2006
* [http://www.nhc.noaa.gov/2002hernan.shtml NHC Hernan Report] accessed January 4, 2006
* [http://www.nhc.noaa.gov/2002kenna.shtml NHC Kenna Report] accessed January 4, 2006
* [http://www.aoml.noaa.gov/hrd/tcfaq/tcfaqHED.html NHC Tropical Cyclone FAQ] accessed January 4, 2006