The 1973 Pacific hurricane season was an above average season, with twelve named

tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...

s in total. Seven storms became hurricanes, of which three were major (Category 3 or higher on the Saffir-Simpson scale). The season officially started May 15, 1973, in the eastern Pacific, and June 1, 1973, in the central Pacific, and lasted until November 30, 1973. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

. All tropical cyclones this season formed in the eastern north

, often off the coast of

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. Most systems traveled generally westward or northwestward, and two reached as far as the waters south of the

Hawaiian Islands The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...

. The most significant system this year was

Hurricane Ava Hurricane Ava was the earliest forming Category 5 hurricane on record in the East Pacific basin. The storm is also tied with 2006's Hurricane Ioke as the fifth-strongest Pacific hurricane on record. It was the first named storm of the 1973 Pacifi ...

, which was the most intense

Pacific hurricane A Pacific hurricane is a tropical cyclone that develops within the northeastern and central Pacific Ocean to the east of 180°W, north of the equator. For tropical cyclone warning purposes, the northern Pacific is divided into three regions: t ...

on record at the time. Several other much weaker tropical cyclones came close to, or made landfall on, the Pacific coast of Mexico. Another was Hurricane Irah, which downed power and communication lines in parts of the Baja California Peninsula. Other landfalling storms caused rain and some flooding. No tropical cyclone this season caused any deaths. __TOC__

Season summary

The season began with Hurricane Ava, which formed as a tropical depression on June 2, and ended with the dissipation of Tropical Lillian on October 9. The season lasted a total of 129 days. No named storms formed in May, three in June, four in July, one in August, three in September, one in October, and none in November. Another six tropical depressions formed during the year, but data on them is unavailable. All of these tropical cyclones formed in the eastern north Pacific

tropical cyclone basin Traditionally, areas of tropical cyclone formation are divided into seven basins. These include the North Atlantic Ocean, the eastern and western parts of the North Pacific Ocean, the Southwest Pacific, the Southwest and Southeast Indian Oceans, ...

, which encompasses the

north of the

equator The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...

east of 140°W. None formed in the central north Pacific, which is the remainder of the Pacific Ocean east of the international dateline. Of the tropical cyclones that formed this year, were twelve tropical storms and seven were hurricanes. Of those hurricanes, three of them were major hurricanes because they reached Category 3 or higher on the Saffir-Simpson Scale. These totals are all below the long-term averages of thirteen tropical storms, nine hurricanes, and four major hurricanes. At the time, this season's total of twelve named tropical cyclones was exactly average, although at the time the climatology in this basin was weak because

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

coverage was spotty before 1966. This season, all advisories and tropical cyclone data were released and collected by two agencies, the

Eastern Pacific Hurricane Center 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 ...

Redwood City, California Redwood City is a city on the San Francisco Peninsula in the San Francisco Bay Area, Bay Area of Northern California, approximately south of San Francisco and northwest of San Jose, California, San Jose. The city's population was 84,292 accor ...

, and the

Central Pacific Hurricane Center The Central Pacific Hurricane Center (CPHC) of the United States National Weather Service is the official body responsible for tracking and issuing tropical cyclone warnings, watches, advisories, discussions, and statements for the Central Pacif ...

Honolulu, Hawaii Honolulu ( ; ) is the List of capitals in the United States, capital and most populous city of the U.S. state of Hawaii, located in the Pacific Ocean. It is the county seat of the Consolidated city-county, consolidated City and County of Honol ...

,. Retrieved 2009-05-20. both of which were coextensive with the

National Weather Service The National Weather Service (NWS) is an Government agency, agency of the Federal government of the United States, United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weathe ...

Forecast Offices in their respective cities. The EPHC covered the area between the coast of North America and 140°W, and the CPHC the remainder of the area.

Systems

Hurricane Ava

A tropical depression formed on June 2. It steadily strengthened and headed in a generally westerly direction. It moved slowly and became Hurricane Ava on June 4. Two days later, it became a major hurricane and it sped up. On June 7, it became a Category 5 hurricane. It then started weakening and slowed down until it dissipated on June 12. No deaths or damages were attributed to Hurricane Ava. Ava's minimum central pressure was 915 millibars, and its

maximum sustained wind 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 certain distance from the center, known as the radius of ma ...

s reached . This made Ava the most intense recorded east Pacific hurricane at the time. Ava reached Category 5 intensity on June 7, the earliest date in an east Pacific season that a hurricane has done so. It was also the second known Category 5 storm in the east Pacific; (behind Patsy in 1959). Ava is the strongest June storm, the fifth most intense east Pacific hurricane, and was the only June Category 5 on record until Hurricane Celia in

2010 The year saw a multitude of natural and environmental disasters such as the 2010 Haiti earthquake, the Deepwater Horizon oil spill, and the 2010 Chile earthquake. The 2009 swine flu pandemic, swine flu pandemic which began the previous year ...

. Ava was also flown into by

hurricane hunter Hurricane hunters, typhoon hunters, or cyclone hunters are aircrews that fly into tropical cyclones to gather weather data. In the United States, the organizations that fly these missions are the United States Air Force Reserve's 53rd Weather ...

aircraft in what was the first penetration of a Pacific hurricane by NOAA aircraft. During these flights, radars and other devices were tested, and wind speed, pressure, and wave heights were measured. This is the reason why Hurricane Ava's pressure is measured instead of estimated. Ava was also photographed from

Skylab Skylab was the United States' first space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three trios of astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Skylab was constructe ...

because it was visible during one of the missions. At that time, it was coincidentally on the surface of the Earth directly underneath the space station. All in all, these made Hurricane Ava one of the best-observed

s at the time.

Tropical Storm Bernice

A nearly stationary disturbance in the

Intertropical Convergence Zone The Intertropical Convergence Zone (ITCZ , or ICZ), known by sailors as the doldrums or the calms because of its monotonous windless weather, is the area where the northeast and the southeast trade winds converge. It encircles Earth near the t ...

spent three days organizing and finally developed into a tropical depression on June 22. The cyclone started heading northwest. After intensifying into a tropical storm, Bernice made landfall on June 23 at a location roughly southwest of

Zihuatanejo Zihuatanejo (), and/or Ixtapa-Zihuatanejo, is the fourth largest city in the Mexican state of Guerrero. It was known by 18th-century English mariners as Chequetan and/or Seguataneo. Politically the city belongs to the municipalities of Mexico, m ...

. It dissipated later that day. Bernice exposed two ships to

gale A gale is a strong wind; the word is typically used as a descriptor in nautical contexts. The U.S. National Weather Service defines a gale as sustained surface wind moving at a speed between .

s, but otherwise neither deaths nor significant impact was reported. At its peak, Tropical Storm Bernice had winds of .

Tropical Storm Claudia

A tropical depression formed June 26 from a westward-moving area of disturbed weather. The next day, it developed gale-force winds and was named Claudia. Claudia headed northwesterly and then northwards and made landfall on June 28 approximately east of

Acapulco Acapulco de Juárez (), commonly called Acapulco ( , ; ), is a city and Port of Acapulco, major seaport in the Political divisions of Mexico, state of Guerrero on the Pacific Coast of Mexico, south of Mexico City. Located on a deep, semicirc ...

. It dissipated inland the next day. No deaths or casualties were reported due to this tropical cyclone.

Hurricane Doreen

On July 18, a tropical storm formed from a disturbance in the

and was named Doreen. It steadily intensified, and became a hurricane on July 19. Doreen briefly reached Category 4 strength on July 21 with a relatively high central pressure of . It then weakened steadily as its path carried it on a direct path to the

Big Island of Hawaii Big or BIG may refer to: * Big, of great size or degree Film and television * ''Big'' (film), a 1988 fantasy-comedy film starring Tom Hanks * ''Big'', a 2023 Taiwanese children's film starring Van Fan and Chie Tanaka * '' Big!'', a Discover ...

. Doreen weakened to a tropical storm as it entered the

's area of responsibility on July 25. A frontal system stuck between two

high-pressure area A high-pressure area, high, or anticyclone, is an area near the surface of a planet where the atmospheric pressure is greater than the pressure in the surrounding regions. Highs are middle-scale meteorological features that result from interpl ...

s weakened as the two areas merged, creating a larger high pressure area that turned Doreen to the southwest on July 27. The hurricane then turned back to the northwest and strengthened back into a hurricane. It became a major hurricane again before weakening. Doreen dissipated August 3. Its remnant vortex continued westward until it dissipated under a trough near the dateline. Doreen's sudden change of track and restrengthening was unusual. From formation to dissipation, Doreen lasted 16.25 days and traveled a distance of . This tied Hurricane Celeste's record for longest-lasting Pacific hurricane. Doreen was also the longest-lasting July tropical cyclone.

Hurricane Fico Hurricane Fico was the longest-lived tropical cyclone of the 1978 Pacific hurricane season and became the longest-lasting Pacific hurricane on record, a record broken by Hurricane Tina fourteen years later. The sixth tropical storm, fourth hurri ...

broke both of these records in the 1978 season. Doreen remains the eighth-longest lasting Pacific tropical cyclone, tied with two other storms. Several ships encountered Doreen. The most serious incident involved a Greek ship called ''Cornelia'' which lost its rudder in waves, but managed to escape and continue on its way to Panama. On the afternoon of July 29, swells and waves were seen from Kapoho. Otherwise, no damages or deaths were blamed on this tropical cyclone.

Hurricane Emily

A depression formed July 21 from squalls in the

Gulf of Tehuantepec The Gulf of Tehuantepec () is a large body of water on the Pacific coast of the Isthmus of Tehuantepec, southeastern Mexico, at . Many (but not all) Pacific hurricanes form in or near this body of water. A strong, gale-force wind called the T ...

and headed west-northwest and strengthened into a tropical storm. Emily continued moving nearly parallel to the coast before turning to the west while steadily intensifying. Emily eventually reached Category 4 intensity on July 22. Emily then weakened as it turned to the northwest. It dissipated on July 28. Emily's wind field was large enough to bring gales areas east of the hurricane from July 22 to 24. This tropical cyclone caused no deaths or damage. Emily had a pressure of 972 mbar, which is unusually high for a hurricane of Category 4 strength.

Hurricane Florence

On July 25, a depression formed off the coast of Guatemala. The storm made a close approach to the Mexican coast as a depression, but did not make landfall. Just after that, it strengthened into a tropical storm. Florence headed west and then west-northwest. It became a hurricane on July 29. It began weakening thereafter. Florence dissipated on July 30. No damages or deaths were reported.

Tropical Storm Glenda

A depression that had formed on July 30 from a tropical disturbance quickly strengthened into a tropical storm and was named Glenda. It took a path similar to both Florence and Emily, but further from the shore. Glenda dissipated August 5. At the time it still had winds of , down from its peak of . No deaths, damage, or other impact was reported.

Tropical Storm Heather

The only storm to form in August this year formed on August 31 from an area of circulation in the ITCZ over the

. It became a tropical depression on August 30. After moving northwest for a bit, it became a tropical storm and headed almost due north towards Mexico. Heather dissipated September 1, just before making landfall. Tropical Storm Heather caused no deaths or damage to any location in the coastal area of the Gulf of Tehuantepec.

Hurricane Irah

A depression formed September 22. It became a tropical storm on September 23 and a hurricane on September 24. Irah took a northwesterly path and reached Category 2 strength on the Saffir-Simpson Hurricane Scale, and then dropped back down to a 1 as it recurved. It made landfall on

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

and entered the

Gulf of California The Gulf of California (), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Vermejo''), is a marginal sea of the Pacific Ocean that separates the Baja California peninsula from ...

as a tropical storm, making landfall again in northwestern Mexico approximately northwest of

Los Mochis Los Mochis () is a coastal city in northern Sinaloa, Mexico. It serves as the municipal seat of the municipality of Ahome. As of the 2010 census, the population was 362,613, which was 61 percent of the municipality's population. Los Mochis is th ...

. Irah's first landfall was the strongest of the season. The hurricane dissipated on September 27 while heading east-northeast over mainland Mexico. Irah blew over some

power Power may refer to: Common meanings * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power, a type of energy * Power (social and political), the ability to influence people or events Math ...

and communication lines during its passage over the southern tip of the Baja California Peninsula. Heavy rain fell over parts of Mexico, with the highest total being at

Sierra de la Laguna The Sierra de la Laguna is a mountain range at the southern end of the Baja California peninsula in Mexico, and is the southernmost range of the Peninsular Ranges System. It is located in La Paz Municipality, Baja California Sur, La Paz Municipa ...

. One person was injured and at least ten houses were destroyed in

Cabo San Lucas Cabo San Lucas (, "Luke the Evangelist, Saint Luke Cape (geography), Cape"), also known simply as Cabo, is a Resort town, resort city at the southern tip of the Baja California peninsula, in the Mexican Political divisions of Mexico, state of Baja ...

. No one was killed. There was some concern that the hurricane could disrupt

splashdown Splashdown is the method of landing a spacecraft or launch vehicle in a body of water, usually by parachute. This has been the primary recovery method of American capsules including NASA’s Mercury, Gemini, Apollo and Orion along with th ...

procedures for astronauts at the end of

Skylab 3 Skylab 3 (also SL-3 and SLM-2) was the second crewed mission to the first American space station, Skylab. The mission began on July 28, 1973, with the launch of NASA astronauts Alan Bean, Owen Garriott, and Jack Lousma in the Apollo command ...

; However, the return to Earth was not seriously affected.

Tropical Storm Jennifer

On September 23, another depression formed. It took a northeasterly path, rotating around the southern periphery of Hurricane Irah as part of a

Fujiwhara interaction The Fujiwhara effect, sometimes referred to as the Fujiwara effect, Fujiwara interaction or binary interaction, is a phenomenon that occurs when two nearby cyclonic vortices move around each other and close the distance between the circulations o ...

. It strengthened into a tropical storm late on September 24. The peak windspeed of this tropical cyclone was . Jennifer then weakened to a depression and turned to the north-northeast. Jennifer brushed the

Islas Marías The Islas Marías ("Mary Islands") make up an archipelago in Mexico, consisting of four islands. They are located in the Pacific Ocean, some off the coast of the state of Nayarit and about southeast of the tip of Baja California. They are part ...

. The cyclone made landfall near just southeast of

Mazatlán Mazatlán () is a city in the Mexican list of states of Mexico, state of Sinaloa. The city serves as the municipal seat for the surrounding , known as the Mazatlán Municipality. It is located on the Pacific Ocean, Pacific coast across from th ...

and dissipated September 27. Tropical Depression Jennifer caused rain over several parts of Mexico. The highest total was at Navarette/ San Blas. No one was killed and no damage was reported.

Hurricane Katherine

Katherine became a tropical storm on September 29, just six hours after forming. It headed out to sea. On October 1, it became a Category 2 hurricane. It peaked in windspeed the next day. After weakening to storm strength, it crossed 140°W and entered the central Pacific. Katherine continued its slightly south of westward track. It dropped to a depression on October 9, and dissipated shortly after that due to the influence of a cold

trough Trough may refer to: In science * Trough (geology), a long depression less steep than a trench * Trough (meteorology), an elongated region of low atmospheric pressure * Trough (physics), the lowest point on a wave * Trough level (medicine), the l ...

Hurricane Lillian

A depression that formed October 5 reached storm strength the same day. It generally paralleled the coast of Mexico far offshore. Lillian reached minimal hurricane strength on October 7 and peaked the next day. The hurricane began to weaken immediately thereafter and dissipated on October 9. Through its life, Lillian at first traveled generally west-northwestward, and then westward. Lillian never threatened land, causing no known impact.

Storm names

The following list of names was used for named storms that formed in the North Pacific Ocean east of 140°W in 1973. It was the same list used in the 1969 season. No names were retired after this season, thus the same list was used again for the 1977 season. Had a named storm formed in the North Pacific between 140°W and the

International Date Line The International Date Line (IDL) is the line extending between the South and North Poles that is the boundary between one calendar day and the next. It passes through the Pacific Ocean, roughly following the 180.0° line of longitude and de ...

in 1973 it would have been assigned a name from the west Pacific's typhoon name list by the

Joint Typhoon Warning Center The Joint Typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South P ...

Guam Guam ( ; ) is an island that is an Territories of the United States, organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. Guam's capital is Hagåtña, Guam, Hagåtña, and the most ...

. Named storms in the table above that crossed into the area during the season are noted (*).

Season effects

This is a table of all of the storms that formed in the 1973 Pacific hurricane season. It includes their name, duration, peak classification and intensities, areas affected, damage, and death totals. Deaths in parentheses are additional and indirect (an example of an indirect death would be a traffic accident), but were still related to that storm. Damage and deaths include totals while the storm was extratropical, a wave, or a low, and all of the damage figures are in 1973 USD.

References

External links

Eastern North Pacific Hurricane Season of 1973

CPHC season summary

ATCR Eastern Pacific summary

{{DEFAULTSORT:1973 Pacific Hurricane Season Articles which contain graphical timelines