Timeline of the 2004 Pacific hurricane season

[nb 2][2][3] Persisting throughout the season was an area of atmospheric and oceanic conditions hostile to tropical cyclones, including below-average sea surface temperatures and a stable air mass.

[nb 3][5] Impacts on land were unusually light during the season, largely on account of the aforementioned ridge steering the vast majority of tropical cyclones out to sea.

[10][11] In mid-October, Tropical Storm Lester caused rainfall of up to 5 in (130 mm) in southern Mexico when it passed close to the coast.

Figures for maximum sustained winds and position estimates are rounded to the nearest five units (knots, miles, or kilometers) and averaged over one minute, following National Hurricane Center practice.

This timeline documents the formation of tropical cyclones as well as the strengthening, weakening, landfalls, extratropical transitions, and dissipations during the season.

A photograph of a tropical storm off the Pacific coast of Mexico. The cloud pattern is tightly wound and well-organized, and there is a dimple near the center of the storm, indicating that it was in the process of developing an eye-like feature. A band of clouds, oriented from west-southwest to east-northeast, can be seen to the south.
Satellite image of Tropical Storm Agatha just before reaching peak intensity late on May 22
A photograph of a tropical storm off the Pacific coast of Mexico. Most of the thicker clouds are on the right side of the storm, particularly in a long curved band that arcs to the south.
Satellite image of Tropical Storm Blas just after peak intensity late on July 13
A map of the path of a hurricane well off the Pacific coast of Mexico. It generally moves west-northwestward, except for a portion midway through its track where the system moves nearly due west.
Track map of Hurricane Celia
A photograph of a hurricane over the Eastern Pacific Ocean. It has a well-defined eye embedded by a round area of thick clouds, though most of the hurricane's cloud cover is located in a long, wide band that curves around the right and bottom flanks.
Satellite image of a strengthening Hurricane Darby late on July 28
A photograph of a tropical depression over the Eastern Pacific Ocean. The system is severely disorganized, to the point where its cloud pattern consists of amorphous blobs.
Satellite image of Tropical Depression Six-E late on August 1
A photograph of a tropical storm over the Eastern Pacific Ocean. It has a tight and well-organized cloud pattern; near the center is a small area of blossoming convection to the right of a tiny hole in the cloud cover.
Satellite image of a strengthening Tropical Storm Estelle late on August 20
A photograph of a hurricane well to the southwest of the Baja California peninsula. The eye is small and oblong, and most of the thicker clouds are in the bottom-right quadrant of the hurricane.
Short-wave infrared satellite image of Hurricane Frank at peak intensity early on August 24
A photograph of a tropical depression over the Eastern Pacific Ocean. Convection associated with the depression is fairly light and mostly confined to the top-left quadrant, with the center of circulation being nearly outside of the convective canopy. A long, broken rainband extends eastward from the northern flank of the depression. A large expanse of wispy, puffy, high clouds surrounds the depression to the top-right, top-left, and bottom-left.
Satellite image of Tropical Depression Nine-E late on August 25
A map of the path of a tropical storm over the Eastern Pacific Ocean. It begins by briefly moving in a west-northwestward direction that parallels the Pacific coast of Mexico; it then curves into a motion that is just north of due west, which it generally maintains until dissipation.
Track map of Tropical Storm Georgette
A photograph of a powerful hurricane off the Pacific coast of Mexico. The eye is cloud-covered but well-defined and surrounded by a thick ring of intense convection. There are several pronounced rainbands spiraling out from the center of the hurricane, separated from each other by a couple arcs of thinner/lower clouds.
Satellite image of Hurricane Howard at peak intensity on September 2
A map of the path of a hurricane off the Pacific coast of Mexico. It parallels the coast for much of its existence, moving in a generally northwestward direction that gradually gains a more northward component as it goes on. After the system degenerates into a remnant low, it moves westward for a short time before switchinf to a southwestward heading, which it maintains until dissipation.
Track map of Hurricane Howard
A map of the path of a hurricane over the Eastern Pacific Ocean. The system initially moves northwestward for a very short distance before switching to a generally westward heading, which it maintains for much of its existence. During the latter half of its tenure, the system briefly moves west-northwestward before nearly stalling. After degenerating into a remnant low, the system turns to the west-southwest and proceeds to gradually curve back to the west, at nearly the same latitude where its previous westward motion had been; it continues in this general direction until it dissipates.
Track map of Hurricane Isis
A photograph of a powerful hurricane off the Pacific coast of Mexico. It has a small and clear eye surrounded by a thick ring of solid white clouds, indicating intense convection. There are several well-pronounced rainbands, especially on the left side of the hurricane. Also on the left side of, and perpendicular to, the hurricane are some thin streaks of high clouds jutting out westward; these are indicative that the hurricane has healthy outflow, which is one of the things a tropical cyclone needs to get stronger and stay strong.
Satellite image of Hurricane Javier just before peak intensity late on September 13
A photograph of a tropical storm over the Eastern Pacific Ocean; it has an oblong shape, much wider horizontally than vertically, though it does have an overall well-organized cloud pattern with multiple spiral bands and a thick area of convection near the center. This storm has some of the same outflow characteristics described in the previous photograph, although these thin streaks are jutting out to the bottom instead of the left.
Satellite image of Tropical Storm Isis late on September 15, just after weakening below hurricane strength
A map of the path of a hurricane near and over the Pacific coast of Mexico. The hurricane parallels the coast for much of its existence, first by moving westward, and then by assuming an extended, somewhat bumpy, but overall northwestward motion. A turn to the north-northeast brings it over the Baja California peninsula and the Gulf of California before it dissipates over the mainland of northwestern Mexico.
Track map of Hurricane Javier
A map of the path of a tropical storm well off the Pacific coast of Mexico. It begins by moving westward before gently curving to the northwest over a short distance; it then abruptly switches to a southwestward motion, continuing in that direction for a short while until dissipation.
Track map of Tropical Storm Kay
A photograph of a tropical storm very near the Pacific coast of Mexico; some of the clouds are spreading over the terrain, though most of it is in some closely grouped rainbands spiraling out to the south of the storm's center. Near the center is a slight dimple in the cloud tops, representing a primitive eye feature.
Satellite image of Tropical Storm Lester shortly after being upgraded late on October 12
A map of the path of a tropical depression over the far eastern portion of the Northern Pacific Ocean. It begins off the coast of Mexico and continues almost due northward to the shoreline, tracking over the southern portion of the Gulf of California in the process.
Track map of Tropical Depression Sixteen-E