Category 4, the second-highest classification on the Saffir–Simpson Hurricane Scale, is used for tropical cyclones that have winds of 130–156 mph (209–251 km/h; 113–136 kn). The division of the eastern and central Pacific basins occurs at 140° W; the eastern Pacific covers area east of 140° W, while the central Pacific extends between 140° W to 180° W. Both basins' division points are at 66° N as a northern point and the equator as the southern point. As of 2019, 126 hurricanes have attained Category 4 status in the northeastern Pacific basins. This list does not include storms that also attained Category 5 status on the scale.
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, and simply cyclone. A hurricane is a tropical cyclone that occurs in the Atlantic Ocean and northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean; in the south Pacific or Indian Ocean, comparable storms are referred to simply as "tropical cyclones" or "severe cyclonic storms".
The knot is a unit of speed equal to one nautical mile per hour, exactly 1.852 km/h. The ISO standard symbol for the knot is kn. The same symbol is preferred by the Institute of Electrical and Electronics Engineers (IEEE); kt is also common, especially in aviation where it is the form recommended by the International Civil Aviation Organization (ICAO). The knot is a non-SI unit. Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour.
An equator of a rotating spheroid is its zeroth circle of latitude (parallel). It is the imaginary line on the spheroid, equidistant from its poles, dividing it into northern and southern hemispheres. In other words, it is the intersection of the spheroid with the plane perpendicular to its axis of rotation and midway between its geographical poles.
Numerous climatological factors influence the formation of hurricanes in the Pacific basins. The North Pacific High and Aleutian Low, usually present between January and April, cause strong wind shear and unfavorable conditions for the development of hurricanes. During its presence, El Niño results in increased numbers of powerful hurricanes through weaker wind shear, while La Niña reduces the number of such hurricanes through the opposite. Global warming may also influence the formation of tropical cyclones in the Pacific basin. During a thirty-year period with two sub-periods, the first between 1975 and 1989 and the second between 1990 and 2004, an increase of thirteen Category 4 or 5 storms was observed from the first sub-period.
The North Pacific High is a semi-permanent, subtropical anticyclone located in the northeastern portion of the Pacific Ocean, located northeast of Hawaii and west of California. It is strongest during the northern hemisphere summer and shifts towards the equator during the winter, when the Aleutian Low becomes more active. It is responsible for California's typically dry summer and fall and typically wet winter and spring, as well as Hawaii's year-round trade winds.
The Aleutian Low is a semi-permanent low-pressure system located near the Aleutian Islands in the Bering Sea during the Northern Hemisphere winter. It is a climatic feature centered near the Aleutian Islands measured based on mean sea-level pressure. It is one of the largest atmospheric circulation patterns in Northern Hemisphere and represents one of the "main centers of action in atmospheric circulation."
Wind shear, sometimes referred to as wind gradient, is a difference in wind speed or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal wind shear. Vertical wind shear is a change in wind speed or direction with change in altitude. Horizontal wind shear is a change in wind speed with change in lateral position for a given altitude.
On the Saffir–Simpson Hurricane Scale, "Category 4" is the second-most powerful classification, with winds ranging between 130–156 mph (209–251 km/h; 113–136 kn). When these hurricanes make landfall, impacts are usually severe but are not as destructive as Category 5 hurricanes that come ashore. The term "maximum sustained wind" refers to the average wind speed measured during the period of one minute at the height of 10 feet (3.0 m) above the ground. The windspeed is measured at that height to prevent disruption from obstructions. Wind gusts in tropical cyclones are usually approximately 30% stronger than the one-minute maximum sustained winds.
The maximum sustained wind associated with a tropical cyclone is a common indicator of the intensity of the storm. Within a mature tropical cyclone, it is found within the eyewall at a distance defined as the radius of maximum wind, or RMW. Unlike gusts, the value of these winds are determined via their sampling and averaging the sampled results over a period of time. Wind measuring has been standardized globally to reflect the winds at 10 metres (33 ft) above the Earth's surface, and the maximum sustained wind represents the highest average wind over either a one-minute (US) or ten-minute time span, anywhere within the tropical cyclone. Surface winds are highly variable due to friction between the atmosphere and the Earth's surface, as well as near hills and mountains over land.
The northeastern Pacific hurricane basins are divided into two parts – eastern and central. The eastern Pacific basin extends from all areas of the Pacific north of the equator east of 140° W, while the central Pacific basin includes areas north of the equator between 140° W and 180° W. Both basins extend to the Arctic Circle at 66° N. When tropical cyclones cross from the Atlantic into the Pacific, the name of the previous storm is retained if the system continues to exhibit tropical characteristics; however, when hurricanes degenerate into a remnant low-pressure area, the system is designated with the next name on the rotating eastern Pacific hurricane naming list.
The Arctic Circle is one of the two polar circles and the most northerly of the five major circles of latitude as shown on maps of Earth. It marks the northernmost point at which the centre of the noon sun is just visible on the December solstice and the southernmost point at which the centre of the midnight sun is just visible on the June solstice. The region north of this circle is known as the Arctic, and the zone just to the south is called the Northern Temperate Zone.
A low-pressure area, low, depression or cyclone is a region on the topographic map where the atmospheric pressure is lower than that of surrounding locations. Low-pressure systems form under areas of wind divergence that occur in the upper levels of the troposphere. The formation process of a low-pressure area is known as cyclogenesis. Within the field of meteorology, atmospheric divergence aloft occurs in two areas. The first area is on the east side of upper troughs, which form half of a Rossby wave within the Westerlies. A second area of wind divergence aloft occurs ahead of embedded shortwave troughs, which are of smaller wavelength. Diverging winds aloft ahead of these troughs cause atmospheric lift within the troposphere below, which lowers surface pressures as upward motion partially counteracts the force of gravity.
Since 1900, 126 Category 4 hurricanes have been recorded in the eastern and central Pacific basins. Of these, fourteen have attained Category 4 status on more than one occasion, by weakening to a status on the Saffir–Simpson Hurricane Scale lower than Category 4 and later restrengthening into a Category 4. Such storms are demarcated by the dates they first attained and the final time they lost the intensity. Only three storms, Hurricane Fico in 1978, Hurricane Norbert in 1984, and Hector in 2018, reached Category 4 status three times or more.
Hurricane Norbert marked the first time a core of a hurricane was fully mapped in three-dimensions. First forming on September 14, 1984 west of the Mexican coast, Norbert gradually intensified, reaching hurricane intensity two days after formation. On September 22, Norbert peaked in strength as a Category 4 hurricane on the Saffir-Simpson Hurricane Scale. While intensifying, Norbert meandered. It moved east, then north, then west, then south, then back towards the east, and finally towards the northeast. After fluctuating in intensity for two more days, Norbert rapidly weakened. It turned towards the northwest and made landfall in southern Baja California Norte as a tropical storm. The combination of Norbert and several other storms left thousands homeless throughout Mexico. The remnants of Hurricane Norbert produced moderate rain over Arizona.
Hurricane Hector was a powerful and long-lived tropical cyclone that was the first to traverse all three North Pacific basins since Genevieve in 2014. The eighth named storm, fourth hurricane, and third major hurricane of the 2018 Pacific hurricane season, Hector originated from an area of low pressure that formed a couple hundred miles west-southwest of Mexico on July 28. Amid favorable weather conditions, a tropical depression formed a few days later on July 31. The depression continued strengthening and became Tropical Storm Hector on the next day. Hector became a hurricane on August 2, and rapidly intensified into a strong Category 2 hurricane later in the day. After weakening while undergoing an eyewall replacement cycle, Hector quickly strengthened into a Category 4 hurricane late on August 5. Over the next week, Hector fluctuated in intensity multiple times due to eyewall replacement cycles and shifting wind shear. Hector achieved its peak intensity on August 6, as a high-end Category 4 hurricane with winds of 155 mph (250 km/h). On the following day, the hurricane bypassed Hawaii approximately 200 mi (320 km) to the south. Increasing wind shear resulted in steady weakening of the storm, beginning on August 11. At that time, Hector accumulated the longest continuous stretch of time as a major hurricane in the northeastern Pacific since reliable records began. Eroding convection and dissipation of its eye marked its degradation to a tropical storm on August 13. The storm subsequently traversed the International Dateline that day. Hector later weakened into a tropical depression on August 15, before dissipating late on August 16.
Between 1970 and 1975, advisories for systems in the eastern Pacific basins were initiated by the Eastern Pacific Hurricane Center (EPHC) as part of the National Weather Service (NWS) office in San Francisco, California. At that time, the advisories released were written in cooperation with the United States Navy Fleet Weather Center in Alameda and the Air Force Hurricane Liaison Officer at the McClellan Air Force Base. Following the move of the hurricane center to Redwood City in 1976, track files were created and altered by Arthur Pike and were later re-modified following the release of a study in 1980. The National Hurricane Center (NHC) extended its authority to the EPHC in 1988, and subsequently began maintaining the tracks.
The Eastern Pacific Hurricane Center was formerly the center responsible for forecasting Pacific hurricanes in the eastern north Pacific east of 140°W. It was part of the Weather Bureau Forecast Office San Francisco and was based in Redwood City.
The National Weather Service (NWS) is an agency of the United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the purposes of protection, safety, and general information. It is a part of the National Oceanic and Atmospheric Administration (NOAA) branch of the Department of Commerce, and is headquartered in Silver Spring, Maryland, within the Washington metropolitan area. The agency was known as the United States Weather Bureau from 1890 until it adopted its current name in 1970.
San Francisco, officially the City and County of San Francisco, is a city in, and the cultural, commercial, and financial center of, Northern California. San Francisco is the 13th-most populous city in the United States, and the fourth-most populous in California, with 884,363 residents as of 2017. It covers an area of about 46.89 square miles (121.4 km2), mostly at the north end of the San Francisco Peninsula in the San Francisco Bay Area, making it the second-most densely populated large US city, and the fifth-most densely populated U.S. county, behind only four of the five New York City boroughs. San Francisco is also part of the fifth-most populous primary statistical area in the United States, the San Jose–San Francisco–Oakland, CA Combined Statistical Area.
A total of 126 Category 4 hurricanes have been recorded in the eastern and central Pacific basins since 1900. Only two Category 4 hurricanes have been recorded in May, in addition to 14 in June, 24 in July, 31 in August, 32 in September, 18 in October, and two in November. No Category 4 storms have developed during the off-season. It is theorized that global warming was responsible for an increase of 13 Category 4 and 5 storms that developed in the eastern Pacific, from 36 in the period of 1975–1989 to 49 in the period of 1990–2004. It was estimated that if sea-surface temperatures ascended by 2 to 2.5 degrees, the intensity of tropical cyclones would increase by 6–10% internationally. During years with the existence of an El Niño, sea-surface temperatures increase in the eastern Pacific, resulting in an increase in activity as vertical wind shear decreases in the Pacific; the opposite happens in the Atlantic basin during El Niño, when wind shear increases creating an unfavourable environment for tropical cyclone formation in the Atlantic. Contrary to El Niño, La Niña increases wind shear over the eastern Pacific and reduces it over the Atlantic.
The presence of a semi-permanent high-pressure area known as the North Pacific High in the eastern Pacific is a dominant factor against formation of tropical cyclones in the winter, as the Pacific High results in wind shear that causes environmental conditions for tropical cyclone formation to be unconducive. Its effects in the central Pacific basin are usually related to keeping cyclones away from the Hawaiian Islands. Due to westward trade winds, hurricanes in the Pacific nearly never head eastward, although several storms have defied the odds and headed eastward. A second factor preventing tropical cyclones from forming during the winter is the occupation of a semi-permanent low-pressure area designated the Aleutian Low between January and April. Its presence over western Canada and the northwestern United States contributes to the area's occurrences of precipitation in that duration. In addition, its effects in the central Pacific near 160° W causes tropical waves that form in the area to drift northward into the Gulf of Alaska and dissipate. Its retreat in late-April allows the warmth of the Pacific High to meander in, bringing its powerful clockwise wind circulation with it. The Intertropical Convergence Zone departs southward in mid-May permitting the formation of the earliest tropical waves, coinciding with the start of the eastern Pacific hurricane season on May 15.
Cooler waters near the Baja California peninsula are thought to prevent storms in the eastern Pacific from transitioning into an extratropical cyclone; as of 2009, only three storms listed in the database are known to have successfully completed an extratropical transition. [ dubious ]
|Season||Dates as a|
|Time as a|
|Unnamed||1957||October 21–22||12 hours||140 mph (220 km/h)||Unknown|
| Dot ||1959||August 2–5||72 hours||150 mph (240 km/h)||952 hPa (28.1 inHg)|
|"Mexico"||1959||October 26–27||36 hours||140 mph (220 km/h)||955 hPa (28.2 inHg)|
|Denise||1971||July 9||12 hours||140 mph (220 km/h)||951 hPa (28.1 inHg)|
|Celeste||1972||August 14||12 hours||130 mph (215 km/h)||940 hPa (28 inHg)|
|Doreen||1973||July 20||6 hours||140 mph (220 km/h)||968 hPa (28.6 inHg)|
|Emily||1973||July 23||6 hours||140 mph (220 km/h)||972 hPa (28.7 inHg)|
|Maggie||1974||August 28–29||24 hours||140 mph (220 km/h)||934 hPa (27.6 inHg)|
|Denise||1975||July 9||12 hours||140 mph (220 km/h)||Unknown|
|Katrina||1975||September 3||6 hours||130 mph (215 km/h)||Unknown|
|Annette||1976||June 8–11||54 hours||140 mph (220 km/h)||925 hPa (27.3 inHg)|
|Iva||1976||August 28||12 hours||130 mph (215 km/h)||Unknown|
|Liza||1976||September 29 – October 1||42 hours||140 mph (220 km/h)||948 hPa (28.0 inHg)|
|Madeline||1976||October 7–8||12 hours||145 mph (230 km/h)||940 hPa (28 inHg)|
| Carlotta ||1978||June 21–22||24 hours||130 mph (215 km/h)||Unknown|
| Fico ||1978||July 11–16||72 hours||140 mph (220 km/h)||955 hPa (28.2 inHg)|
|Hector||1978||July 25||18 hours||140 mph (220 km/h)||Unknown|
|Norman||1978||September 2–3||36 hours||140 mph (220 km/h)||Unknown|
| Susan ||1978||October 21||6 hours||130 mph (215 km/h)||Unknown|
|Enrique||1979||August 22||18 hours||145 mph (230 km/h)||Unknown|
|Ignacio||1979||October 27–28||18 hours||145 mph (230 km/h)||938 hPa (27.7 inHg)|
|Kay||1980||September 18||18 hours||140 mph (220 km/h)||Unknown|
|Olivia||1982||September 21–22||30 hours||145 mph (230 km/h)||Unknown|
|Barbara||1983||June 13–14||24 hours||130 mph (215 km/h)||Unknown|
|Henriette||1983||July 30–31||18 hours||130 mph (215 km/h)||Unknown|
| Kiko ||1983||September 2–4||66 hours||145 mph (230 km/h)||Unknown|
| Raymond ||1983||October 11–15||42 hours||145 mph (230 km/h)||Unknown|
|Tico||1983||October 19||6 hours||130 mph (215 km/h)||Unknown|
|Douglas||1984||June 28–30||48 hours||145 mph (230 km/h)||Unknown|
|Elida||1984||July 1||6 hours||130 mph (215 km/h)||Unknown|
|Iselle||1984||August 8–9||12 hours||130 mph (215 km/h)||Unknown|
| Norbert ||1984||September 21–24||36 hours||130 mph (215 km/h)||Unknown|
| Ignacio ||1985||July 23–24||24 hours||130 mph (215 km/h)||Unknown|
|Jimena||1985||July 24||12 hours||130 mph (215 km/h)||Unknown|
|Rick**||1985||September 8–10||42 hours||145 mph (230 km/h)||Unknown|
|Estelle*||1986||July 20–21||36 hours||130 mph (215 km/h)||Unknown|
| Javier ||1986||August 25||12 hours||130 mph (215 km/h)||Unknown|
|Roslyn||1986||October 18–20||42 hours||145 mph (230 km/h)||Unknown|
|Max||1987||September 12–14||42 hours||155 mph (250 km/h)||Unknown|
|Ramon||1987||October 9–10||36 hours||140 mph (220 km/h)||Unknown|
|Hector||1988||August 2–4||36 hours||145 mph (230 km/h)||935 hPa (27.6 inHg)|
| Fabio ||1988||August 3||12 hours||140 mph (220 km/h)||943 hPa (27.8 inHg)|
|Octave||1989||September 13||6 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
|Raymond||1989||September 30 – October 1||30 hours||145 mph (230 km/h)||935 hPa (27.6 inHg)|
|Hernan||1990||July 22–25||60 hours||155 mph (250 km/h)||928 hPa (27.4 inHg)|
| Marie ||1990||September 11||24 hours||140 mph (220 km/h)||944 hPa (27.9 inHg)|
|Odile||1990||September 26–27||36 hours||145 mph (230 km/h)||935 hPa (27.6 inHg)|
| Trudy ||1990||October 19–27||78 hours||155 mph (250 km/h)||924 hPa (27.3 inHg)|
| Jimena ||1991||September 23–26||48 hours||130 mph (215 km/h)||945 hPa (27.9 inHg)|
|Kevin||1991||September 29 – October 2||72 hours||145 mph (230 km/h)||935 hPa (27.6 inHg)|
|Celia||1992||June 27–28||42 hours||145 mph (230 km/h)||935 hPa (27.6 inHg)|
| Estelle ||1992||July 12–14||30 hours||140 mph (220 km/h)||943 hPa (27.8 inHg)|
|Frank||1992||July 17–19||36 hours||145 mph (230 km/h)||935 hPa (27.6 inHg)|
|Orlene||1992||September 5–7||60 hours||145 mph (230 km/h)||934 hPa (27.6 inHg)|
| Iniki ||1992||September 11–12||24 hours||145 mph (230 km/h)||938 hPa (27.7 inHg)|
|Tina||1992||September 29 – October 2||66 hours||150 mph (240 km/h)||932 hPa (27.5 inHg)|
|Virgil||1992||October 3||6 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
|Dora||1993||July 16–17||24 hours||130 mph (215 km/h)||945 hPa (27.9 inHg)|
|Fernanda||1993||August 11–13||42 hours||145 mph (230 km/h)||934 hPa (27.6 inHg)|
| Keoni ||1993||August 16–17||24 hours||130 mph (215 km/h)||Unknown|
|Greg||1993||August 19–20||30 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
|Jova||1993||September 1||12 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
|Kenneth||1993||September 10–12||36 hours||150 mph (240 km/h)||932 hPa (27.5 inHg)|
|Lidia||1993||September 11||24 hours||150 mph (240 km/h)||930 hPa (27 inHg)|
|Lane||1994||September 6–7||18 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
|Olivia||1994||September 25–26||24 hours||150 mph (240 km/h)||923 hPa (27.3 inHg)|
|Adolph||1995||June 18||6 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
| Barbara ||1995||July 10–14||60 hours||140 mph (220 km/h)||940 hPa (28 inHg)|
|Juliette||1995||September 20–21||24 hours||150 mph (240 km/h)||930 hPa (27 inHg)|
|Douglas**||1996||August 1–2||36 hours||130 mph (215 km/h)||946 hPa (27.9 inHg)|
|Felicia||1997||July 19||18 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
|Jimena||1997||August 27–28||36 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
|Nora||1997||September 21||6 hours||130 mph (215 km/h)||950 hPa (28 inHg)|
| Pauline ||1997||October 7–8||12 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
|Blas||1998||June 25||24 hours||140 mph (220 km/h)||943 hPa (27.8 inHg)|
|Estelle||1998||August 2||6 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
| Howard ||1998||August 23–26||60 hours||150 mph (240 km/h)||948 hPa (28.0 inHg)|
|Dora||1999||August 10–13||72 hours||140 mph (220 km/h)||943 hPa (27.8 inHg)|
|Carlotta||2000||June 21–22||24 hours||155 mph (250 km/h)||932 hPa (27.5 inHg)|
|Adolph||2001||May 28–29||30 hours||145 mph (230 km/h)||940 hPa (28 inHg)|
| Juliette ||2001||September 24–26||42 hours||145 mph (230 km/h)||923 hPa (27.3 inHg)|
|Fausto||2002||August 24–25||24 hours||145 mph (230 km/h)||936 hPa (27.6 inHg)|
|Ele||2002||August 29||6 hours||130 mph (215 km/h)||945 hPa (27.9 inHg)|
|Howard||2004||September 2–3||18 hours||140 mph (220 km/h)||943 hPa (27.8 inHg)|
|Javier||2004||September 13–15||54 hours||150 mph (240 km/h)||930 hPa (27 inHg)|
|Kenneth||2005||September 18–19||18 hours||130 mph (215 km/h)||947 hPa (28.0 inHg)|
|Daniel||2006||July 20–23||72 hours||150 mph (240 km/h)||933 hPa (27.6 inHg)|
|John||2006||August 30||12 hours||130 mph (215 km/h)||948 hPa (28.0 inHg)|
|Flossie||2007||August 11–13||60 hours||140 mph (220 km/h)||949 hPa (28.0 inHg)|
|Norbert||2008||October 8||6 hours||130 mph (215 km/h)||945 hPa (27.9 inHg)|
|Felicia||2009||August 5–7||36 hours||145 mph (230 km/h)||935 hPa (27.6 inHg)|
|Jimena||2009||August 30 – September 1||60 hours||155 mph (250 km/h)||931 hPa (27.5 inHg)|
|Adrian||2011||June 10||18 hours||140 mph (220 km/h)||944 hPa (27.9 inHg)|
|Dora||2011||July 21–22||30 hours||155 mph (250 km/h)||929 hPa (27.4 inHg)|
|Eugene||2011||August 3–4||18 hours||140 mph (220 km/h)||942 hPa (27.8 inHg)|
| Hilary ||2011||September 23–27||60 hours||145 mph (230 km/h)||942 hPa (27.8 inHg)|
|Kenneth||2011||November 22–23||18 hours||145 mph (230 km/h)||940 hPa (28 inHg)|
|Emilia||2012||July 10||12 hours||140 mph (220 km/h)||945 hPa (27.9 inHg)|
|Amanda||2014||May 25–26||36 hours||155 mph (250 km/h)||932 hPa (27.5 inHg)|
|Cristina||2014||June 12||18 hours||150 mph (240 km/h)||935 hPa (27.6 inHg)|
|Iselle||2014||August 4–5||18 hours||140 mph (220 km/h)||947 hPa (28.0 inHg)|
|Odile||2014||September 14||12 hours||140 mph (220 km/h)||918 hPa (27.1 inHg)|
|Simon||2014||October 4||6 hours||130 mph (215 km/h)||946 hPa (27.9 inHg)|
|Andres||2015||June 1||24 hours||145 mph (230 km/h)||937 hPa (27.7 inHg)|
| Blanca ||2015||June 3–6||24 hours||145 mph (230 km/h)||936 hPa (27.6 inHg)|
|Dolores||2015||July 15||6 hours||130 mph (215 km/h)||946 hPa (27.9 inHg)|
| Hilda ||2015||August 8||12 hours||140 mph (220 km/h)||946 hPa (27.9 inHg)|
| Ignacio ||2015||August 29–30||24 hours||145 mph (230 km/h)||942 hPa (27.8 inHg)|
|Jimena||2015||August 29 – September 1||84 hours||155 mph (250 km/h)||932 hPa (27.5 inHg)|
| Kilo ||2015||August 30–31||36 hours||140 mph (220 km/h)||940 hPa (28 inHg)|
|Olaf*||2015||October 19–21||42 hours||150 mph (240 km/h)||938 hPa (27.7 inHg)|
|Sandra||2015||November 26||18 hours||150 mph (240 km/h)||934 hPa (27.6 inHg)|
|Blas||2016||July 6||6 hours||140 mph (220 km/h)||947 hPa (28.0 inHg)|
|Georgette||2016||July 25||12 hours||130 mph (215 km/h)||952 hPa (28.1 inHg)|
| Lester ||2016||August 29–31||36 hours||145 mph (230 km/h)||944 hPa (27.9 inHg)|
| Madeline ||2016||August 30||6 hours||130 mph (215 km/h)||950 hPa (28 inHg)|
|Seymour||2016||October 25–26||24 hours||150 mph (240 km/h)||940 hPa (28 inHg)|
| Fernanda ||2017||July 14–16||30 hours||145 mph (230 km/h)||947 hPa (28.0 inHg)|
|Kenneth||2017||August 21||6 hours||130 mph (215 km/h)||952 hPa (28.1 inHg)|
|Aletta||2018||June 8||12 hours||140 mph (220 km/h)||943 hPa (27.8 inHg)|
|Bud||2018||June 12||12 hours||140 mph (220 km/h)||943 hPa (27.8 inHg)|
| Hector ||2018||August 5–10||96 hours||155 mph (250 km/h)||936 hPa (27.6 inHg)|
| Norman ||2018||August 30 – September 3||54 hours||150 mph (240 km/h)||937 hPa (27.7 inHg)|
|Olivia||2018||September 7||6 hours||130 mph (215 km/h)||951 hPa (28.1 inHg)|
|Rosa||2018||September 28||18 hours||145 mph (230 km/h)||940 hPa (28 inHg)|
|Sergio||2018||October 4||24 hours||140 mph (220 km/h)||943 hPa (27.8 inHg)|
|Month||Number of storms|
Of the 126 Category 4 hurricanes that have formed in the eastern and central Pacific basins, 28 have made landfall. Of them, four made landfall at Category 4 intensity, three at Category 3, eleven at Categories 2 and 1, eight as tropical storms, and six as tropical depressions. Several of these storms weakened slightly after attaining Category 4 status as they approached land; this is usually a result of dry air, shallower water due to shelving, cooler waters, or interaction with land. Only in six years – 1976, 1983, 1992, 1997, 2014 and 2018 – more than one Category 4 hurricane made landfall, and only during one year – 2018 – did four Category 4 hurricanes made landfall.
|Name||Year||Category 4||Category 3||Category 2||Category 1||Tropical storm||Tropical depression||Source(s)|
|Raymond||1983||—||—||—||—||—||Maui, Oʻahu, Kauaʻi|
|Norbert||1984||—||—||—||—||Baja California Sur state||—|
|Raymond||1989||—||—||—||—|| Baja California Sur state|
|Nora||1997||—||—||—|| Baja California Sur state|
Baja California state
|Juliette||2001||—||—||—||—||Baja California Sur state||Sonora state|
|Javier||2004||—||—||—||—||—||Baja California Sur state|
|John||2006||—||—||Baja California Sur state||—||—||—|
|Norbert||2008||—||—||Baja California Sur state||Sonora state||—||—|
|Jimena||2009||—||—||Baja California Sur state||—||—||—|
|Odile||2014||—||Baja California Sur state||—||—||Sonora state||—|
|Blanca||2015||—||—||—||—||Baja California Sur state||—|
|Bud||2018||—||—||—||—||Baja California Sur state||—|
|Rosa||2018||—||—||—||—||—||Baja California state|
|Sergio||2018||—||—||—||—|| Baja California Sur state|
If a storm makes landfall in the same Mexican state more than once, it is only listed for the most intense landfall.
The 2002 Atlantic hurricane season was a borderline-average Atlantic hurricane season. It officially started on June 1, 2002 and ended on November 30, dates which conventionally limit the period of each year when most tropical cyclones develop in the Atlantic Ocean. The season produced fourteen tropical cyclones, of which twelve developed into named storms; four became hurricanes, and two attained major hurricane status. While the season's first cyclone did not develop until July 14, activity quickly picked up; the 2002 season tied with 2010 in which a record number of tropical storms, eight, developed in the month of September. It ended early however, with no tropical storms forming after October 6—a rare occurrence caused partly by El Niño conditions. The most intense hurricane of the season was Hurricane Isidore with a minimum central pressure of 934 mbar, although Hurricane Lili attained higher winds and peaked at Category 4 whereas Isidore only reached Category 3. The season's low activity is reflected in the low cumulative accumulated cyclone energy (ACE) rating of 67. ACE is, broadly speaking, a measure of the power of the hurricane multiplied by the length of time it existed, so low number reflects the small number of strong storms and preponderance of tropical storms.
The 1993 Atlantic hurricane season was a below average Atlantic hurricane season that produced ten tropical cyclones, eight tropical storms, four hurricanes, and one major hurricane. It officially started on June 1 and ended on November 30, dates which conventionally delimit the period during which most tropical cyclones form in the Atlantic Ocean. The first tropical cyclone, Tropical Depression One, developed on May 31, while the final storm, Tropical Depression Ten, dissipated on September 30, well before the average dissipation date of a season's last tropical cyclone; this represented the earliest end to the hurricane season in ten years. The most intense hurricane, Emily, was a Category 3 on the Saffir–Simpson Hurricane Scale that paralleled close to the North Carolina coastline causing minor damage and a few deaths before moving out to sea.
The 1992 Atlantic hurricane season had one of the latest dates on record for the first named storm. The season officially began on June 1, 1992, and lasted until November 30, 1992. The first storm, an unnamed subtropical storm, developed in the central Atlantic on April 21, over a month before the official start of hurricane season. The most significant storm of the season was Hurricane Andrew, which at the time was the costliest U.S. hurricane. After crossing the Bahamas, the hurricane made landfall in Florida and Louisiana. It caused $27.3 billion in damage, mostly in Florida, and 65 fatalities. Andrew was also the strongest hurricane of the season, reaching winds of 175 mph (282 km/h) while approaching Florida.
The 1991 Atlantic hurricane season was the first season since 1984 in which no hurricanes developed from tropical waves, which are the source for most North Atlantic tropical cyclones. The hurricane season officially began on June 1, and ended on November 30. It was the least active in four years due to higher than usual wind shear across the Atlantic Ocean. The first storm, Ana, developed on July 2 off the southeast United States and dissipated without causing significant effects. Two other tropical storms in the season – Danny and Erika – did not significantly affect land. Danny dissipated east of the Lesser Antilles, and Erika passed through the Azores before becoming extratropical. In addition, there were four non-developing tropical depressions. The second depression of the season struck Mexico with significant accompanying rains.
Hurricane Cesar–Douglas was one of the few tropical cyclones to survive the crossover from the Atlantic to east Pacific basin, and was the last to receive two names upon doing so. Cesar was the third named storm and second hurricane of the 1996 Atlantic hurricane season. The system formed in the southern Caribbean Sea and affected several countries in South America before crossing Nicaragua and entering the eastern Pacific where it was renamed Douglas. The storm killed 113 people in Central and South America and left 29 others missing, mainly due to flooding and mudslides.
The 2005 Atlantic hurricane season was the most active Atlantic hurricane season in recorded history, shattering numerous records. The impact of the season was widespread and catastrophic. Its storms caused an estimated total of 3,960 deaths and approximately $180.7 billion in damage, making it the second costliest season on record, surpassed only by the 2017 season.
The 2001 Pacific hurricane season was a near average season. The most notable storm that year was Hurricane Juliette, which caused devastating floods in Baja, California, leading to 12 fatalities and $400 million worth of damage. Two other storms were notable in their own rights, Hurricane Adolph became the strongest May Hurricane until 2014 when both records set by Adolph and Juliette were broken by Hurricanes Amanda and Odile. Tropical Storm Barbara passed just north of Hawaii, bringing minimal impact. The season officially began on May 15, 2001 in the eastern Pacific, and on June 1, 2001 in the central Pacific, and lasted until November 30, 2001. These dates conventionally delimit the period of each year when most tropical cyclones form in this part of the Pacific Ocean. The first storm developed on May 25, while the last storm dissipated on November 3.
The 2000 Pacific hurricane season was an above-average Pacific hurricane season, although most of the storms were weak and short-lived. There were few notable storms this year. Tropical Storms Miriam, Norman, and Rosa all made landfall in Mexico with minimal impact. Hurricane Daniel briefly threatened the U.S. state of Hawaii while weakening. Hurricane Carlotta was the strongest storm of the year and the second-strongest June hurricane in recorded history. Carlotta killed 18 people when it sank a freighter. Overall, the season was significantly more active than the previous season, with 19 tropical storms. In addition, six hurricanes developed. Furthermore, there were total of two major hurricanes, Category 3 or greater on the Saffir–Simpson hurricane wind scale.
The 1994 Pacific hurricane season was the final season of the eastern north Pacific's consecutive active hurricane seasons that unofficially started in 1982. The season officially started on May 15, 1994, in the eastern Pacific, and on June 1, 1994, in the central Pacific, and lasted until November 30, 1994. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean. The first tropical cyclone formed on June 18, while the last system dissipated on October 26. This season, twenty-two tropical cyclones formed in the north Pacific Ocean east of the dateline, with all but two becoming tropical storms or hurricanes. A total of 10 hurricanes occurred, including five major hurricanes.
The 1992 Pacific hurricane season was the most active Pacific hurricane season on record, featuring 27 named storms, and the second-costliest Pacific hurricane season in history, behind only the 2013 season. The season also produced the second-highest ACE value on record in the basin, surpassed by the 2018 season. The season officially started on May 15 in the eastern Pacific, and on June 1 in the central Pacific, and lasted until November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean. However, these bounds were easily exceeded when Hurricane Ekeka formed on January 28 and again a couple months later with Tropical Storm Hali.
The 1991 Pacific hurricane season was a near-average Pacific hurricane season. The worst storm this year was Tropical Storm Ignacio, which killed ten people in Mexico. Elsewhere, Tropical Storm Ignacio injured forty people in Mexico, and Hurricane Fefa caused flooding in Hawaii. Hurricane Kevin was the strongest system of the season and became the then longest-lasting hurricane in the eastern north Pacific basin. Hurricane Nora was the strongest November storm at that time.
Hurricane Dora was one of few tropical cyclones to track across all three north Pacific basins. The fourth named storm, third hurricane, and second major hurricane of the 1999 Pacific hurricane season, Dora developed on August 6 from a tropical wave to the south of Mexico. Forming as a tropical depression, it gradually strengthened and was upgraded to Tropical Storm Dora later that day. Thereafter, Dora began heading in a steadily westward, before becoming a hurricane on August 8. Under warm sea surface temperatures (SST's) and low wind shear, the storm continued to intensify, eventually peaking as a 140 mph (220 km/h) Category 4 hurricane on August 12. While passing south of Hawaii, Dora significantly fluctuated in intensity, ranging from peak intensity as a Category 4 hurricane to a low-end Category 1 hurricane. While crossing the International Dateline on August 20, Dora weakened to a tropical storm. After weakening to a tropical depression on August 22, Dora dissipated on August 23 while centered several hundred miles north of Wake Island.
Hurricane Rosa was the only Pacific hurricane to make landfall during the above-average 1994 Pacific hurricane season. It killed at least 4 people in Mexico. Moisture from the hurricane was a factor in widespread flooding in the U.S. state of Texas that killed 22 people and caused hundreds of millions of dollars in damage in October 1994. The pre-Rosa tropical depression formed on October 8 before degenerating the next day. It reformed on October 10 and steadily strengthened as it approached Mexico. Ultimately peaking as a Category 2 hurricane on the Saffir-Simpson Hurricane Scale right before landfall, Rosa was the final hurricane, nineteenth tropical storm, and second-last tropical cyclone of the 1994 Pacific hurricane season.
Hurricane Gilma was one of the most intense Pacific hurricanes on record and the second of three Category 5 hurricanes during the active 1994 Pacific hurricane season. Developing from a westward tracking tropical wave over the open waters of the eastern Pacific Ocean on July 21, the pre-Gilma tropical depression was initially large and disorganized. Gradual development took place over the following day before rapid intensification began. By July 23, the storm intensified into a hurricane and later a Category 5 storm on July 24. As Gilma reached this intensity, it crossed into the Central Pacific basin, the fourth consecutive storm to do so.
The 1991 Pacific hurricane season produced 16 tropical depressions, 14 of which became tropical storms or hurricanes. The season officially started on May 15, 1997 in the Eastern Pacific—designated as the area east of 140°W—and on June 1, 1997 in the Central Pacific, which is between the International Date Line and 140°W. The season officially ended in both basins on November 30, 1997. These dates typically limit the period of each year when most tropical cyclones form in the eastern Pacific basin. This timeline documents all the storm formations, strengthening, weakening, landfalls, extratropical transitions, as well as dissipation. The timeline also includes information which was not operationally released, meaning that information from post-storm reviews by the National Hurricane Center, such as information on a storm that was not operationally warned on, has been included.