The 1998 Pacific hurricane season was the annual cycle of tropical cyclone formation over the Pacific Ocean north of the equator and east of the International Date Line. The season officially began on May 15 in the Eastern Pacific proper (east of 140°W) and June 1 in the Central Pacific (140°W to the International Date Line), and ended on November 30 in both areas. This is historically the period during which most tropical cyclogenesis occurs in these respective areas. The first system, Tropical Storm Agatha, formed on June 11. The final system to dissipate was Hurricane Lester, which did so on October 26. Hurricane Madeline formed shortly after Lester, but dissipated several days earlier.
The season generated a below-average number of thirteen named tropical storms. However, nine became hurricanes, which was near average. An above-average number of six further intensified into major hurricanes—Category 3 or higher on the five-level Saffir–Simpson scale, with maximum sustained winds of at least 111 mph (179 km/h). Additionally, three tropical depressions developed that did not attain tropical storm strength. Prevailing atmospheric currents steered the vast majority of storms out to sea; only two made landfall, which was below the contemporary average of three or four. Hurricane Isis struck Baja California Sur and Sinaloa as a tropical storm and a minimal hurricane, respectively, while Tropical Storm Javier came ashore in Jalisco as a tropical depression. Tropical Storm Frank and hurricanes Lester and Madeline passed close enough to Mexico to produce peripheral effects on land; the remnants of Madeline contributed to deadly and destructive flooding in Texas.
This timeline documents tropical cyclone formations, strengthening, weakening, landfalls, and dissipations during the season. It includes information that was not released during the season, meaning that data from post-storm reviews by the National Hurricane Center and the Central Pacific Hurricane Center has been included.
The time stamp for each event is first stated using Coordinated Universal Time (UTC), the 24-hour clock where 00:00 = midnight UTC. The NHC uses both UTC and the time zone where the center of the tropical cyclone was then located. Prior to 2015, two time zones were utilized in the Eastern Pacific basin: Pacific for the Eastern Pacific, and Hawaii−Aleutian for the Central Pacific. In this timeline, the respective area time is included in parentheses. Additionally, figures for maximum sustained winds and position estimates are rounded to the nearest 5 units (miles, or kilometers), following NHC practice. Direct wind observations are rounded to the nearest whole number. Atmospheric pressures are listed to the nearest millibar and nearest hundredth of an inch of mercury. __TOC__
Timeline of events
May There was no tropical cyclone activity in May.
May 15 The 1998 Eastern Pacific hurricane season officially begins.
June June 1 The 1998 Central Pacific hurricane season officially begins.
June 11 12:00 UTC (5:00 a.m. PDT) at Tropical Depression forms from a tropical wave well off the Pacific coast of Mexico.
June 13
06:00 UTC (11:00 p.m. PDT, June 12) at Tropical Depression strengthens into Tropical Storm Agatha about south of the southern tip of the Baja California peninsula.
June 14 00:00 UTC (5:00 p.m. PDT, June 13) at Tropical Storm Agatha attains its peak intensity, with maximum sustained winds of and a minimum central pressure of , about southwest of the southern tip of the Baja California peninsula.
June 15 18:00 UTC (11:00 a.m. PDT) at Tropical Storm Agatha weakens into a tropical depression about west-southwest of the southern tip of the Baja California peninsula.
June 16 18:00 UTC (11:00 a.m. PDT) at Tropical Depression Agatha is last noted as a tropical cyclone about west-southwest of the southern tip of the Baja California peninsula, dissipating shortly thereafter.
June 19 18:00 UTC (11:00 a.m. PDT) at Tropical Depression forms from an area of unsettled weather off the Pacific coast of Mexico.
June 21 00:00 UTC (5:00 p.m. PDT, June 20) at Tropical Depression attains its peak intensity, with maximum sustained winds of and a minimum central pressure of , about southeast of Socorro Island.
June 22
00:00 UTC (5:00 p.m. PDT, June 21) at Tropical Depression is last noted as a tropical cyclone about west of Socorro Island, dissipating shortly thereafter. 00:00 UTC (5:00 p.m. PDT, June 21) at Tropical Depression forms from a tropical wave about south of the Gulf of Tehuantepec. 12:00 UTC (5:00 a.m. PDT) at Tropical Depression strengthens into Tropical Storm Blas about south of Puerto Ángel, Oaxaca.
June 23 18:00 UTC (11:00 a.m. PDT) at Tropical Storm Blas strengthens into a Category 1 hurricane on the Saffir–Simpson scale about south-southwest of Acapulco, Guerrero.
June 24 06:00 UTC (11:00 p.m. PDT, June 23) at Hurricane Blas strengthens to Category 2 intensity about southwest of Acapulco. 12:00 UTC (5:00 a.m. PDT) at Hurricane Blas strengthens to Category 3 intensity about southwest of Acapulco.
June 25
00:00 UTC (5:00 p.m. PDT, June 24) at Hurricane Blas strengthens to Category 4 intensity about west-southwest of Acapulco. 06:00 UTC (11:00 p.m. PDT, June 24) at Hurricane Blas attains its peak intensity, with maximum sustained winds of and a minimum central pressure of , about south-southeast of the southern tip of the Baja California peninsula.
June 26 00:00 UTC (5:00 p.m. PDT, June 25) at Hurricane Blas weakens to Category 3 intensity about south of the southern tip of the Baja California peninsula. 18:00 UTC (11:00 a.m. PDT) at Hurricane Blas weakens to Category 2 intensity about south-southwest of the southern tip of the Baja California peninsula.
June 27 06:00 UTC (11:00 p.m. PDT, June 26) at Hurricane Blas weakens to Category 1 intensity about southwest of the southern tip of the Baja California peninsula.
June 28 12:00 UTC (5:00 a.m. PDT) at Hurricane Blas weakens into a tropical storm about west-southwest of the southern tip of the Baja California peninsula.
June 30 00:00 UTC (5:00 p.m. PDT, June 29) at Tropical Storm Blas weakens into a tropical depression about west-southwest of the southern tip of the Baja California peninsula. 18:00 UTC (11:00 a.m. PDT) at Tropical Depression Blas is last noted as a tropical cyclone about west-southwest of the southern tip of the Baja California peninsula, dissipating shortly thereafter.
July July 17 06:00 UTC (11:00 p.m. PDT, July 16) at A tropical depression forms from a tropical wave about south of Manzanillo, Colima. 12:00 UTC (5:00 a.m. PDT) at The recently formed tropical depression strengthens into Tropical Storm Celia about southwest of Manzanillo.
July 19
00:00 UTC (5:00 p.m. PDT, July 18) at Tropical Storm Celia attains its peak intensity, with maximum sustained winds of and a minimum central pressure of , about west-southwest of the southern tip of the Baja California peninsula.
July 20 06:00 UTC (11:00 p.m. PDT, July 19) at Tropical Storm Celia weakens into a tropical depression about west of the southern tip of the Baja California peninsula.
July 21 06:00 UTC (11:00 p.m. PDT, July 20) at Tropical Depression Celia is last noted as a tropical cyclone about west of the southern tip of the Baja California peninsula, dissipating shortly thereafter.
July 23 00:00 UTC (5:00 p.m. PDT, July 22) at Tropical Depression forms from a tropical wave about south of the southern tip of the Baja California peninsula. 18:00 UTC (11:00 a.m. PDT) at Tropical Depression strengthens into Tropical Storm Darby about south-southwest of the southern tip of the Baja California peninsula.
July 24 12:00 UTC (5:00 a.m. PDT) at Tropical Storm Darby strengthens into a Category 1 hurricane about southwest of the southern tip of the Baja California peninsula.
July 25 00:00 UTC (5:00 p.m. PDT, July 24) at Hurricane Darby strengthens to Category 2 intensity about southwest of the southern tip of the Baja California peninsula. 06:00 UTC (11:00 p.m. PDT, July 24) at Hurricane Darby strengthens to Category 3 intensity about southwest of the southern tip of the Baja California peninsula. 18:00 UTC (11:00 a.m. PDT) at Hurricane Darby weakens to Category 2 intensity about southwest of the southern tip of the Baja California peninsula.
July 26
18:00 UTC (11:00 a.m. PDT) at Hurricane Darby restrengthens to Category 3 intensity about west-southwest of the southern tip of the Baja California peninsula. It simultaneously attains its peak intensity, with maximum sustained winds of and a minimum central pressure of .
July 28 06:00 UTC (11:00 p.m. PDT, July 27) at Hurricane Darby weakens back to Category 2 intensity about west-southwest of the southern tip of the Baja California peninsula. 18:00 UTC (11:00 a.m. PDT) at Hurricane Darby weakens to Category 1 intensity about west of the southern tip of the Baja California peninsula, and later crosses into the Central Pacific basin.
July 29 12:00 UTC (2:00 a.m. HST) at Hurricane Darby weakens into a tropical storm about east of Hilo, Hawaii. 18:00 UTC (11:00 a.m. PDT) at Tropical Depression forms from a tropical wave about south-southwest of Acapulco.
July 30 06:00 UTC (11:00 p.m. PDT, July 29) at Tropical Depression strengthens into Tropical Storm Estelle about southwest of Acapulco.
July 31 06:00 UTC (8:00 p.m. HST, July 30) at Tropical Storm Darby weakens into a tropical depression about northeast of Hilo. 06:00 UTC (11:00 p.m. PDT, July 30) at Tropical Storm Estelle strengthens into a Category 1 hurricane about southwest of Manzanillo.
August August 1
00:00 UTC (2:00 p.m. HST, July 31) at Tropical Depression Darby is last noted as a tropical cyclone about north-northeast of Hilo, and dissipates shortly thereafter. 12:00 UTC (5:00 a.m. PDT) at Hurricane Estelle strengthens to Category 2 intensity about south-southwest of the southern tip of the Baja California peninsula. 18:00 UTC (11:00 a.m. PDT) at Hurricane Estelle strengthens to Category 3 intensity about southwest of the southern tip of the Baja California peninsula.
August 2 06:00 UTC (11:00 p.m. PDT, August 1) at Hurricane Estelle strengthens to Category 4 intensity about southwest of the southern tip of the Baja California peninsula. It simultaneously attains its peak intensity, with maximum sustained winds of and a minimum central pressure of . 12:00 UTC (5:00 a.m. PDT) at Hurricane Estelle weakens to Category 3 strength about southwest of the southern tip of the Baja California peninsula.
August 3 00:00 UTC (5:00 p.m. PDT, August 2) at Hurricane Estelle weakens to Category 2 intensity about west-southwest of the southern tip of the Baja California peninsula. 12:00 UTC (5:00 a.m. PDT) at Hurricane Estelle weakens to Category 1 intensity about west-southwest of the southern tip of the Baja California peninsula.
August 4 06:00 UTC (11:00 p.m. PDT, August 3) at Hurricane Estelle weakens into a tropical storm about west-southwest of the southern tip of the Baja California peninsula.
August 5 12:00 UTC (5:00 a.m. PDT) at Tropical Storm Estelle weakens into a tropical depression about west of the southern tip of the Baja California peninsula, and later crosses into the Central Pacific basin.
August 6 12:00 UTC (5:00 a.m. PDT) at Tropical Depression forms from a tropical wave about south-southwest of the southern tip of the Baja California peninsula.
August 8
00:00 UTC (5:00 p.m. PDT, August 7) at Tropical Depression strengthens into Tropical Storm Frank about southwest of the southern tip of the Baja California peninsula. 18:00 UTC (8:00 a.m. HST) at Tropical Depression Estelle is last noted as a tropical cyclone about east-northeast of Hilo, dissipating shortly thereafter.
August 9 00:00 UTC (5:00 p.m. PDT, August 8) at Tropical Storm Frank attains its peak intensity, with maximum sustained winds of and a minimum central pressure of , about northwest of Cabo San Lázaro.