Tropical Storm Julio (1984)
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The 1984 Pacific hurricane season featured numerous tropical cyclones, several of which were impactful to land. It was a busy hurricane season with 21 named storms, 13 hurricanes, and 7 major hurricanes, the latter of which are Category 3 or stronger cyclones on the Saffir–Simpson scale. This activity was unusual given the presence of a La Niña, which typically suppresses Central and East Pacific tropical cyclone activity, and only average sea surface temperatures. Seasonal activity began on May 17 and ended on November 8. This lies within the confines of a traditional hurricane season which begins on May 15 in the East Pacific and June 1 in the Central Pacific, and ends on November 30 in both basins. These dates conventionally delimit the period during each year when most tropical cyclones form. The drought-stricken
Hawaiian Islands The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kur ...
received beneficial rainfall from Hurricane Douglas in July and Tropical Storm Kenna in August. The remnants of hurricanes Iselle, Marie, Norbert, and Odile all contributed to enhanced precipitation across the
Southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, Ne ...
during the season, including snowfall in higher elevations; flash flooding killed one person in Texas. Hurricane Lowell attracted widespread coverage for damaging the ''Blue Falcon'' and forcing the rescue of its 23 crewmembers. In September, torrential rains from Hurricane Odile in Southern Mexico severely damaged crops, inflicted water damage to about 900 homes, and left thousands of residents displaced or without normal services. The storm killed at least 21 people. Multiple hurricanes contributed to rough surf along the California coastline, resulting in one death and hundreds of water rescues.


Systems

ImageSize = width:800 height:205 PlotArea = top:10 bottom:80 right:20 left:20 Legend = columns:3 left:30 top:58 columnwidth:270 AlignBars = early DateFormat = dd/mm/yyyy Period = from:01/05/1984 till:01/12/1984 TimeAxis = orientation:horizontal ScaleMinor = grid:black unit:month increment:1 start:01/05/1984 Colors = id:canvas value:gray(0.88) id:GP value:red id:TD value:rgb(0.38,0.73,1) legend:Tropical_Depression_=_≤38_mph_(≤62_km/h) id:TS value:rgb(0,0.98,0.96) legend:Tropical_Storm_=_39–73_mph_(63–117_km/h) id:C1 value:rgb(1,1,0.80) legend:Category_1_=_74–95_mph_(118–153_km/h) id:C2 value:rgb(1,0.91,0.46) legend:Category_2_=_96–110_mph_(154–177_km/h) id:C3 value:rgb(1,0.76,0.25) legend:Category_3_=_111–129_mph_(178–208_km/h) id:C4 value:rgb(1,0.56,0.13) legend:Category_4_=_130–156_mph_(209–251_km/h) id:C5 value:rgb(1,0.38,0.38) legend:Category_5_=_≥157_mph_(≥252_km/h) Backgroundcolors = canvas:canvas BarData = barset:Hurricane bar:Month PlotData= barset:Hurricane width:11 align:left fontsize:S shift:(4,-4) anchor:till from:17/05/1984 till:21/05/1984 color:TS text:Alma (TS) from:28/05/1984 till:05/06/1984 color:C1 barset:break barset:skip from:12/06/1984 till:18/06/1984 color:TS text:Boris (C1) from:17/06/1984 till:26/06/1984 color:C2 text:Cristina (C2) from:25/06/1984 till:06/07/1984 color:C4 text:Douglas (C4) from:28/06/1984 till:08/07/1984 color:C4 text:Elida (C4) from:03/07/1984 till:10/07/1984 color:C2 text:Fausto (C2) from:07/07/1984 till:14/07/1984 color:C3 text:Genevieve (C3) barset:break from:27/07/1984 till:01/08/1984 color:TS text:Hernan (TS) from:03/08/1984 till:12/08/1984 color:C4 text:Iselle (C4) from:15/08/1984 till:20/08/1984 color:TS text:Julio (TS) from:16/08/1984 till:22/08/1984 color:C3 text:Keli (C3) from:16/08/1984 till:21/08/1984 color:TS text:Kenna (TS) from:23/08/1984 till:02/09/1984 color:TS text:Lala (TS) from:26/08/1984 till:30/08/1984 color:C1 text:Lowell (C1) barset:break from:04/09/1984 till:05/09/1984 color:TS text:Moke (TS) from:05/09/1984 till:11/09/1984 color:C1 text:Marie (C1) from:14/09/1984 till:26/09/1984 color:C4 text: Norbert (C4) from:17/09/1984 till:23/09/1984 color:C2 text: Odile (C2) from:26/09/1984 till:03/10/1984 color:C3 text:Polo (C3) from:07/10/1984 till:16/10/1984 color:TS text:Rachel (TS) from:31/10/1984 till:08/11/1984 color:TS text:Simon (TS) barset:break bar:Month width:5 align:center fontsize:S shift:(0,-20) anchor:middle color:canvas from:01/05/1984 till:01/06/1984 text:May from:01/06/1984 till:01/07/1984 text:June from:01/07/1984 till:01/08/1984 text:July from:01/08/1984 till:01/09/1984 text:August from:01/09/1984 till:01/10/1984 text:September from:01/10/1984 till:01/11/1984 text:October from:01/11/1984 till:01/12/1984 text:November TextData = pos:(570,30) text:"(From the" pos:(617,30) text:" Saffir–Simpson scale)"


Tropical Storm Alma

On May 13, an area of disturbed weather within the
Intertropical Convergence Zone The Intertropical Convergence Zone (ITCZ ), 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 thermal e ...
(ITCZ) crossed Panama and
Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...
into the East Pacific. Strong westerly wind shear inhibited this disturbance initially, but atmospheric conditions improved over subsequent days, allowing it to become the season's first tropical depression around 18:00 UTC on May 17. The system increased rapidly in size as developing high pressure to its north brought it over very warm ocean waters. The depression intensified into Tropical Storm Alma by 18:00 UTC on May 18, attaining peak winds of 60 mph (95 km/h) the next day. After fluctuating in intensity for a few days, Alma weakened to a tropical depression and dissipated after 18:00 UTC on May 21.


Hurricane Boris

A tropical depression developed south of the Gulf of Tehuantepec around 18:00 UTC on May 28. It intensified into Tropical Storm Boris over the next six hours, and further development allowed it to become the season's first hurricane by 12:00 UTC on May 30. After reaching peak winds of 75 mph (120 km/h), Boris weakened and began to move erratically as upper-level troughing progressed over western Mexico. The storm conducted a counter-clockwise loop over numerous days, finally tracking west again as ridging redeveloped to its north. The system, which had persisted as a tropical depression during that time, regained tropical storm intensity on June 13 before crossing into cooler waters. Boris dissipated after 00:00 UTC on June 18 to the southwest of the Baja California Peninsula.


Hurricane Cristina

A weak cold-core low drifted westward across the southern Gulf of Mexico, acting as the impetus for a tropical depression that formed south of Mexico around 06:00 UTC on June 17. The depression intensified into Tropical Storm Cristina within six hours and further organized into a hurricane around 18:00 UTC on June7 19. The next day, it attained Category 2 strength with winds of 105 mph (165 km/h). High pressure over Oklahoma, and upper-level troughing over southern California, both retrograded west as Cristina developed. This caused the storm to track in stair-step fashion throughout its duration. The cyclone weakened to a tropical storm on August 21, but it regained hurricane strength two days later before feeling the effects of an upper-level trough off Baja California. Cristina weakened rapidly, dissipating after 00:00 UTC on June 26.


Hurricane Douglas

An area of disturbed weather formed east of Clipperton Island on June 23, organizing into a tropical depression around 00:00 UTC on June 25. The newly-developed system moved west-northwest and intensified over warm waters, becoming Tropical Storm Douglas by 18:00 UTC on June 25 and strengthening into a hurricane about 48 hours later. In a 24-hour period ending at 00:00 UTC on June 29, the cyclone's winds increased from 85 mph (140 km/h) to 145 mph (230 km/h), equivalent to Category 4 intensity. At its peak, Douglas displayed a well-defined
eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...
on
satellite imagery Satellite images (also Earth observation imagery, spaceborne photography, or simply satellite photo) are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell ima ...
. After persisting as an intense hurricane for several days, it encountered waters cooler than on July 2 and began to weaken. Douglas crossed into the Central Pacific as a tropical depression the following day, where it ultimately dissipated after 18:00 UTC on July 6. The remnants of the cyclone crossed
Maui The island of Maui (; Hawaiian: ) is the second-largest of the islands of the state of Hawaii at 727.2 square miles (1,883 km2) and is the 17th largest island in the United States. Maui is the largest of Maui County's four islands, which ...
and the Big Island on July 8–9, where it produced rainfall accumulations up to over the parched slopes of those islands.


Hurricane Elida

A tropical disturbance formed south of Salina Cruz, Oaxaca, on June 26 and was upgraded to a tropical depression around 00:00 UTC on June 28. By 12:00 UTC the next day, the system intensified into Tropical Storm Elida. Like Douglas before it, Elida entered a period of rapid intensification and became a Category 4 hurricane, peaking with winds of 130 mph (215 km/h). The cyclone fluctuated in intensity before starting a more definitive weakening trend after July 3. Around this time, the steering regime around Elida collapsed, causing the system to backtrack toward the east within low-level flow imparted by Tropical Storm Fausto to the north and Hurricane Genevieve to the east. Tracking over cold waters, the system dissipated after 18:00 UTC on July 8.


Hurricane Fausto

An area of disturbed weather crossed
Guatemala Guatemala ( ; ), officially the Republic of Guatemala ( es, República de Guatemala, links=no), is a country in Central America. It is bordered to the north and west by Mexico; to the northeast by Belize and the Caribbean; to the east by H ...
into the East Pacific on July 1. It passed over extremely warm waters and rapidly organized accordingly, becoming a tropical depression around 12:00 UTC on July 3 and a tropical storm, Fausto, six hours later. The newly-formed cyclone moved northwest, guided by two potent upper-level troughs to its north. Fausto became a hurricane around 18:00 UTC on July 4 and further developed into a Category 2 storm with winds of 110 mph (175 km/h) at 00:00 UTC on July 6. After maintaining hurricane strength until July 8, Fausto entered progressively cooler waters and began to weaken. Ridging became established north of the storm, which curved west and dissipated after 00:00 UTC on July 10.


Hurricane Genevieve

To the southeast of Hurricane Fausto, a new area of disturbed weather formed south of the Gulf of Tehuantepec on July 6. The system coalesced into a tropical depression by 06:00 UTC on July 7; within twelve hours, it became Tropical Storm Genevieve. The system moved northwest parallel to the Mexico coastline, and warm waters facilitated its continued development. Genevieve became a hurricane at 18:00 UTC on July 8 and a major hurricane, with peak winds of 115 mph (185 km/h), 48 hours later. Its forward trajectory soon brought the cyclone over colder waters, and the cyclone began to weaken. It curved north and made landfall about 90 mi (150 km) northwest of
Cabo San Lucas Cabo San Lucas (, "Saint Luke Cape"), or simply just Cabo, is a resort city at the southern tip of the Baja California Peninsula, in the Mexican state of Baja California Sur. As at the 2020 Census, the population of the city was 202,694 inhabitan ...
,
Baja California Sur Baja California Sur (; 'South Lower California'), officially the Free and Sovereign State of Baja California Sur ( es, Estado Libre y Soberano de Baja California Sur), is the least populated state and the 31st admitted state of the 32 federal ent ...
, at 09:00 UTC on July 14, possessing 35 mph (55 km/h) winds by that point. Genevieve transitioned into an
extratropical cyclone Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of ...
three hours later before dissipating.


Tropical Storm Hernan

A tropical depression formed well south of Baja California Sur at 12:00 UTC on July 27. The cyclone moved west-northwest and then west, becoming Tropical Storm Hernan by 00:00 UTC on July 28. Unlike previous storms before it, Hernan encountered a less conducive environment of cool waters and wind shear. It reached peak winds of 50 mph (85 km/h) on July 29, thus ending a string of East Pacific hurricanes. Hernan slowly succumbed to hostile conditions and dissipated after 00:00 UTC on August 1.


Hurricane Iselle

A tropical disturbance drifted into the Gulf of Tehuantepec on August 3 and organized into a tropical depression around 18:00 UTC that day. A potent upper-level trough dug southward into the coastal waters of California, creating a steering pattern that shunted the system northwest. The depression intensified into a tropical storm 24 hours after formation, a hurricane by 06:00 UTC on August 6, and a major hurricane around 12:00 UTC on August 8. Six hours later, Iselle became a Category 4 cyclone with winds of 130 mph (215 km/h). The system soon encountered ocean waters of and weakened to the west of Baja California, dissipating after 12:00 UTC on August 12. As the cyclone passed offshore, small craft warnings were enacted along the Mexico coastline. Some street flooding was reported in
Acapulco Acapulco de Juárez (), commonly called Acapulco ( , also , nah, Acapolco), is a city and major seaport in the state of Guerrero on the Pacific Coast of Mexico, south of Mexico City. Acapulco is located on a deep, semicircular bay and has bee ...
, Guerrero. Farther north in western Texas, moisture from Iselle collided with cooler air from the north, causing thunderstorms and heavy rainfall. Up to fell in El Paso. Flash flood watches had been hoisted across several counties, and minor street flooding was reported in both El Paso and Juarez. Some mountain roads were impassable. A girl was killed when her normally dry home in a creekbed was overwhelmed by a flood. One person was also injured by lightning. At beaches in Orange County, California, waves up to necessitated numerous lifeguard rescues. Some 385 rescues occurred in Newport Beach, while an additional 50 people were saved at San Clemente; rescues more than tripled the average at Huntington Beach.


Tropical Storm Julio

At 00:00 UTC on August 15, a new tropical depression formed south of Acapulco. High pressure, extending across Mexico from the Gulf of Mexico, directed the system west-northwest. It strengthened into Tropical Storm Julio eighteen hours later and soon peaked with winds of 60 mph (95 km/h). An expansive upper-level outflow setup was disrupted by an increase in wind shear, which caused Julio to weaken despite warm ocean waters. The center dissipated about halfway between Socorro Island and Cabo Corrientes,
Jalisco Jalisco (, , ; Nahuatl: Xalixco), officially the Free and Sovereign State of Jalisco ( es, Estado Libre y Soberano de Jalisco ; Nahuatl: Tlahtohcayotl Xalixco), is one of the 31 states which, along with Mexico City, comprise the 32 Federal En ...
, after 12:00 UTC on August 20.


Hurricane Keli

In mid-August, an area of disturbed weather persisted within the ITCZ across several days. It definitively organized into Tropical Depression One-C around 18:00 UTC on August 16, becoming Tropical Storm Keli six hours later. The storm moved well to the south of the Hawaiian Islands, but it intensified rapidly on a course toward
Johnston Atoll Johnston Atoll is an Unincorporated territories of the United States, unincorporated territory of the United States, currently administered by the United States Fish and Wildlife Service (USFWS). Johnston Atoll is a National Wildlife Refuge and ...
. Keli became a hurricane around 06:00 UTC on August 8 and a major hurricane, with peak winds of 115 mph (185 km/h), when a
reconnaissance aircraft A reconnaissance aircraft (colloquially, a spy plane) is a military aircraft designed or adapted to perform aerial reconnaissance with roles including collection of imagery intelligence (including using photography), signals intelligence, as ...
intercepted it about 48 hours later. A nearby upper-level trough began to shear Keli, directing its convection to the north; low-level flow, meanwhile, forced the storm's actual center westward. The system passed about 70 mi (110 km) southwest of Johnston Atoll, where an evacuation had been ordered. About of rainfall and wind gusts to were recorded there. The system dissipated after 00:00 UTC on August 22.


Tropical Storm Kenna

An area of disturbed weather crossed Panama on August 7. It moved on a persistent westerly course under ridging that extended from California to the Hawaiian Islands. The system organized into a tropical depression over the far western reaches of the East Pacific basin around 18:00 UTC on August 16. Six hours later, it strengthened into Tropical Storm Kenna. On August 18, the cyclone crossed into the Central Pacific, attaining maximum winds of 60 mph (95 km/h) as estimated by a reconnaissance aircraft despite a generally disheveled presentation on satellite imagery. Gradual weakening occurred thereafter, and Kenna degenerated to a remnant low after 18:00 UTC on August 21. The remnants of the cyclone curved northwest and moved across the Big Island of Hawaii, producing rainfall accumulations of across its windward districts. These rains were beneficial during an ongoing drought.


Tropical Storm Lala

An area of vigorous thunderstorm activity developed within the ITCZ over the open East Pacific on August 21. It moved west-northwest and acquired a well-defined circulation, thus becoming a tropical depression around 18:00 UTC on August 23. The system crossed into the Central Pacific early on August 26. Four days later, a reconnaissance aircraft intercepted the cyclone for the first time, finding winds of 50 mph (85 km/h) and supporting the system's upgrade to Tropical Storm Lala. Lala tracked to the south of the Hawaiian Islands and Johnston Atoll, dissipating after 18:00 UTC on September 2.


Hurricane Lowell

A
tropical wave A tropical wave (also called easterly wave, tropical easterly wave, and African easterly wave), in and around the Atlantic Ocean, is a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which ...
entered the Gulf of Tehuantepec on August 22. The system moved rapidly westward amid a favorable combination of low wind shear and warm ocean waters. It became a tropical depression around 06:00 UTC on August 26, coalesced into Tropical Storm Lowell twelve hours later, and intensified into a hurricane by 18:00 UTC on August 27. The next day, Lowell acquired peak winds of 85 mph (140 km/h). It later encountered cooler waters, which caused the cyclone to dissipate after 06:00 UTC on August 30. As a hurricane, Lowell clipped the freighter ''Blue Falcon'', cracking its bow and forcing the rescue of 23 crewmembers.


Tropical Storm Moke

In August 1984, expansive ridging persisted across the North Pacific while a series of cold-core lows wandered underneath. One such upper low persisted near the
International Date Line The International Date Line (IDL) is an internationally accepted demarcation on the surface of Earth, running between the South and North Poles and serving as the boundary between one calendar day and the next. It passes through the Pacific O ...
in close vicinity to Midway Island—as evidenced by low temperatures aloft in radiosondes released there—and developed a surface circulation, being declared as a tropical depression by the Japan Meteorological Agency on September 2. While the lack of satellite coverage made tracking the system difficult, forecasters believe it organized into Tropical Storm Moke by 06:00 UTC on September 4. Spotty satellite imagery showed a well-organized storm with hints of an eye. Moke moved north-northeast in advance of an upper-level trough, which soon imparted shear and caused rapid weakening. The system transitioned back into an extratropical cyclone after 00:00 UTC on September 5. As a tropical system, Moke produced wind gusts up to 35 mph (55 km/h) on Midway Island and slightly more severe conditions on Kure Atoll.


Hurricane Marie

A tropical depression formed south of Manzanillo, Colima, at 12:00 UTC on September 5. It became Tropical Storm Marie six hours later and further intensified into a hurricane by 00:00 UTC on September 7. Marie northwest over warm waters and reached peak winds of 90 mph (150 km/h) on September 8. As the storm bypassed Baja California to the west, it encountered colder waters and began to weaken. A reconnaissance aircraft mission into the storm later that day measured a large, poorly-defined 58 mi (93 km) diameter eye. Subsequent investigations of Marie found a storm becoming increasingly disheveled over waters; it dissipated after 00:00 UTC on September 11. Rough surf up to was reported at Huntington Beach, California, where a 50-year-old man drowned. Lifeguards performed more than 30 rescues there. Humidity from the storm spawned swift-moving thunderstorms across southern California. The roof of a bowling alley collapsed, submerging bowling lanes in of water. Floods inundated roads, including U.S. Route 95 in California, and frequent lightning caused power outages to dozen of homes.


Hurricane Norbert

At 18:00 UTC on September 14, the season's next tropical depression developed southwest of Baja California. It strengthened into Tropical Storm Norbert six hours later. Embedded within weak steering flow, the newly named cyclone wound its way north, particularly after upper-level trough developed over the Rocky Mountains. Norbert steadily intensified, organizing into a hurricane around 12:00 UTC on September 16 and a major hurricane by 00:00 UTC on September 18. The potent storm fluctuated between Category 3–4 intensity for many days thereafter, reaching peak winds of 130 mph (215 km/h) on four separate occasions. On September 23, a reconnaissance aircraft intercepted Norbert and its well-defined eye, marking the first time that the inner core of a hurricane was mapped three-dimensionally. Between 00:00–06:00 UTC on September 26, Norbert made landfall near Punta Abreojos as a tropical storm. While the storm is officially recognized as dissipating over Baja California, forecasters in Arizona expressed high confidence that it remained a tropical cyclone into that state. In the small fishing communities of Punta Abreojos and La Bocana along the coastline of Baja California Sur, 90 percent of structures were demolished. One person was killed, one person was reported missing, and more than $140 million in damage occurred there. The remnants of the cyclone produced sporadic rainfall across Mexico. Slightly higher accumulations were reported in Arizona, where flash flood watches were hoisted across several counties and some school districts released students early owing to those concerns.
"Heavy rains expected, but no major flooding", p.1

"Norbert subdued, but 3 still needed storm rescue", p.2
/ref> Accumulations peaked at on Kitt Peak in Arizona. Normally dry roadways were inundated with runoff, and three people were rescued from a rain-filled streambed. About 50 roads were closed in Tucson and surrounding areas. Sustained winds up to 30 mph (45 km/h) were observed in similar locales.


Hurricane Odile

At 18:00 UTC on September 17, a tropical depression formed to the south of Acapulco. It developed into Tropical Storm Norbert six hours later and into a hurricane by 00:00 UTC on September 20. The cyclone originally moved west-northwest and north under the influence of a ridge near Acapulco. However, that ridge shifted southwest while an upper-level trough progressed into northern Mexico, forcing Odile to the east. The hurricane attained peak winds of 105 mph (165 km/h), Category 2 intensity, early on September 22 to the east of nearby Hurricane Norbert. Another upper-level trough diving into Baja California caused Odile to quickly veer northwest, and it made landfall about 45 mi (75 km) northwest of Zihuatanejo, Guerrero, at 18:00 UTC on September 22, harboring winds of 60 mph (95 km/h). The system transitioned into an extratropical cyclone and dissipated after six hours. Odile produced copious amounts of rainfall across Southern Mexico, including a maximum accumulation of in Costa Azul/Acapulco. Between the Zihuatanejo and Acapulco airports, some 87 commercial flights were cancelled, including 50 charter flights. Hotels were deserted across typically busy tourist areas. The heavy precipitation inundated roadways and filtered into the lobby of the Zihuatanejo airport. Throughout the state of Guerrero, 44 riverbank and mountain communities were isolated, encompassing some 30,000 residents. The cyclone overturned a barge on the Atoyac River, resulting in the drownings of 18 passengers and 3 crewmembers. Odile compounded the effects of previous systems which in totality yielded Mexico's wettest year since 1978. Those floods damaged countless structures, severely affected crops, left thousands of residents displaced, and killed many people.


Hurricane Polo

An area of disturbed weather entered the Gulf of Tehuantepec on September 24, organizing into a tropical depression by 00:00 UTC on September 26. The depression moved west-southwest initially, but it curved northwest after becoming Tropical Storm Polo around 18:00 UTC on September 28. At 00:00 UTC on September 30, Polo became the season's final hurricane. Two days later, it became the season's last major hurricane with peak winds of 115 mph (185 km/h). The cyclone curved northeast ahead of an upper-level trough over Baja California, and that feature brought Polo into colder waters and higher wind shear. The system crossed Baja California Sur between 06:00–12:00 UTC on October 3 as a 35 mph (55 km/h) tropical depression. It dissipated over the Gulf of California after 12:00 UTC. Moisture from the remnants of the storm streamed north into the Southwestern United States, prompting flash flood watches across Utah, Arizona, New Mexico, and Texas. Up to of rain was recorded in Reserve, New Mexico. Heavy rain caused rockslides in Utah west of Castle Dale. Heavy rain across Colorado translated to snow in higher elevations, with advisories warning of the potential for accumulations.


Tropical Storm Rachel

A tropical disturbance crossed
Costa Rica Costa Rica (, ; ; literally "Rich Coast"), officially the Republic of Costa Rica ( es, República de Costa Rica), is a country in the Central American region of North America, bordered by Nicaragua to the north, the Caribbean Sea to the no ...
on October 4. It remained steady state for several days while moving west but ultimately organized into a tropical depression around 18:00 UTC on October 7. The depression encountered warm waters along its track, which fueled its organization into Tropical Storm Rachel by 06:00 UTC on October 9. The next day, Rachel attained peak winds of 65 mph (100 km/h). A broad upper-level trough over Baja California steered the cyclone west-northwest into cooler waters, and it began to weaken. Rachel maintained intensity as a tropical depression for many days before dissipating over the open East Pacific after 12:00 UTC on October 16.


Tropical Storm Simon

Tropical Depression Twenty-Three, the season's final tropical cyclone, formed in the Gulf of Tehuantepec around 00:00 UTC on October 31. As high pressure centered over the Gulf of Mexico slid west, the newly designated system likewise followed a westerly course. At 00:00 UTC on November 1, the depression intensified into Tropical Storm Simon. The next day, it attained peak winds of 65 mph (100 km/h). Simon soon encountered increasingly cool waters and began to weaken, dissipating over the open East Pacific after 00:00 UTC on November 8 and drawing the season to a close.


Other systems

Outside the purview of the official hurricane database, the Eastern Pacific Hurricane Center also documented several unofficial tropical depressions during the season. On June 29, a poorly organized area of convection formed south-southeast of the Gulf of Tehuantepec. It became a tropical depression on June 30 but failed to organize further owing to influence by Hurricane Elida to its west-northwest. It dissipated south of Acapulco on July 2. A fast-moving disturbance in the ITCZ developed on July 13 and separated from that feature, becoming a tropical depression on July 23. However, it dissipated over colder waters in the far western reaches of the East Pacific two days later. On August 21, another small area of disturbed weather formed along the ITCZ. It coalesced into a tropical depression on August 23 but did not organize further and instead dissipated on August 26 as it crossed into the Central Pacific. On September 11, another tropical depression formed over the Gulf of Tehuantepec. However, it was positioned on the south side of an upper-level trough extending from Texas into Mexico, and the shearing effects of that feature caused the cyclone to dissipate on September 22; its remnants continued inland about 50 mi (85 km) east of Salina Cruz. Three days later, a new tropical depression developed about 60 mi (95 km) west-southwest of Zihuatanejo. In spite of very warm ocean waters, the system struggled under the influence of Hurricane Norbert to the west and the close proximity of the
Sierra Madre del Sur The Sierra Madre del Sur is a mountain range in southern Mexico, extending from southern Michoacán east through Guerrero, to the Isthmus of Tehuantepec in eastern Oaxaca. Geography The Sierra Madre del Sur joins with the Eje Volcánico Transv ...
. It moved onshore about 35 mi (55 km) southeast of Manzanillo, Colima, at 02:00 UTC on September 15. On November 3, an area of convection formed northwest of Clipperton Island. It developed into a tropical depression on November 5 but did not intensify further as it met cooler waters. The system dissipated after just twelve hours.


Storm names

The following names were used for named storms that formed in the eastern Pacific in 1984. Names that were not assigned are marked in gray. Three names from the Central Pacific list were used – Keli, Lala, and Moke.


Season effects

This is a table of all the storms that formed in the 1984 Pacific hurricane season. It includes their duration, names, affected areas, damages, 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
tropical wave A tropical wave (also called easterly wave, tropical easterly wave, and African easterly wave), in and around the Atlantic Ocean, is a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which ...
, or a
low Low or LOW or lows, may refer to: People * Low (surname), listing people surnamed Low Places * Low, Quebec, Canada * Low, Utah, United States * Lo Wu station (MTR code LOW), Hong Kong; a rail station * Salzburg Airport (ICAO airport code: LO ...
, and all the damage figures are in USD. Potential tropical cyclones are not included in this table.


See also

* List of Pacific hurricanes * Pacific hurricane season *
1984 Atlantic hurricane season The 1984 Atlantic hurricane season was the most active since 1971, though the season was below average in hurricanes and major hurricanes. It officially began on June 1, 1984, and lasted until November 30, 1984. These dates conventionally delimi ...
* 1984 Pacific typhoon season *
1984 North Indian Ocean cyclone season The 1984 North Indian Ocean cyclone season was part of the annual cycle of tropical cyclone formation. The season has no official bounds but cyclones tend to form between April and December. These dates conventionally delimit the period of each yea ...
* Southern Hemisphere tropical cyclone seasons: 1983–84, 1984–85


References


External links


Eastern North Pacific Tropical Cyclones of 1984

CPHC's Season Summary
{{DEFAULTSORT:1984 Pacific Hurricane Season Pacific hurricane seasons Articles which contain graphical timelines 1984 EPAC