The 2023 Pacific hurricane season was a fairly active Pacific hurricane season. In the eastern Pacific basin (east of 140°W), 17 named storms formed; 10 of those became hurricanes, and 8 further intensified into major hurricanes (category 3 or higher on the 5-level Saffir–Simpson wind speed scale). In the central Pacific basin (between 140°W and the International Date Line), no tropical cyclones formed (for the fourth consecutive season), though four entered into the basin from the east.[1][2] The season officially began on May 15, 2023, in the eastern Pacific, and on June 1 in the central Pacific; it ended in both on November 30. These dates, adopted by convention, historically describe the period in each year when most tropical cyclogenesis occurs in these regions of the Pacific.[3] The season's first system, Tropical Storm Adrian, developed on June 27, and its last, Tropical Storm Ramon, dissipated on November 26.
This timeline documents tropical cyclone formations, strengthening, weakening, landfalls, extratropical transitions, and dissipations during the season. It includes information that was not released throughout the season, meaning that data from post-storm reviews by the National Hurricane Center, such as a storm that was not initially warned upon, has been included.
By convention, meteorologists use one time zone when issuing forecasts and making observations: Coordinated Universal Time (UTC), and also use the 24-hour clock (where 00:00 = midnight UTC).[4] Tropical cyclone advisories in the Eastern North Pacific basin use both UTC and the nautical time zone where the center of the tropical cyclone is currently located. Time zones utilized (east to west) are: Central, Mountain, Pacific and Hawaii. In this timeline, all information is listed by UTC first, with the respective regional time zone included in parentheses. Additionally, figures for maximum sustained winds and position estimates are rounded to the nearest 5 units (knots, miles, or kilometers), following National Hurricane Center 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.
Timeline
May
No tropical cyclones form in the Eastern Pacific basin during the month of May.
May 15
The Eastern Pacific hurricane season officially begins.[3]
June
June 1
The Central Pacific hurricane season officially begins.[3]
18:00 UTC (11:00 a.m. PDT) at 13°42′N123°54′W / 13.7°N 123.9°W / 13.7; -123.9 (Calvin reaches its peak intensity.) – Hurricane Calvin reaches its peak intensity, with maximum sustained winds of 125 mph (205 km/h) and a minimum central pressure of 953 mbar (28.14 inHg), about 1,115 mi (1,795 km) west-southwest of the southern tip of the Baja California Peninsula.[8]
Satellite image of Hurricane Dora at peak intensity early on August 6
00:00 UTC (5:00 p.m. PDT, August 5) at 13°12′N135°36′W / 13.2°N 135.6°W / 13.2; -135.6 (Dora reaches its peak intensity.) – Hurricane Dora reaches its peak intensity, with maximum sustained winds of 150 mph (240 km/h) and a minimum central pressure of 939 mbar (27.73 inHg), about 1,805 mi (2,910 km) west-southwest of the southern tip of the Baja California peninsula.[10]
06:00 UTC (8:00 p.m. HST, September 17) at 12°18′N146°30′W / 12.3°N 146.5°W / 12.3; -146.5 – Tropical Depression Twelve‑E degenerates into a remnant low far southeast of the Big Island of Hawaii, and later dissipates.[20]
03:00 UTC (10:00 p.m. CDT, October 24) at 16°06′N99°42′W / 16.1°N 99.7°W / 16.1; -99.7 (Otis reaches Category 5 strength and its peak intensity.) – Hurricane Otis intensifies to Category 5 strength about 60 mi (95 km) south-southeast of Acapulco; it simultaneously reaches its peak intensity, with maximum sustained winds of 165 mph (270 km/h) and a minimum central pressure of 922 mbar (27.23 inHg), making it the strongest storm of the season.[27]
00:00 UTC (7:00 p.m. CDT, October 31) at 11°42′N89°24′W / 11.7°N 89.4°W / 11.7; -89.4 – Tropical Storm Pilar reaches its peak intensity, with maximum sustained winds of 65 mph (100 km/h) and a minimum central pressure of 995 mbar (29.38 inHg), about 90 mi (150 km) off the coast of El Salvador.[29]
November 5
18:00 UTC (11:00 a.m. MST)[nb 7] at 10°30′N113°54′W / 10.5°N 113.9°W / 10.5; -113.9 – Tropical Storm Pilar degenerates into a remnant low about 890 mi (1,435 km) south-southwest of the southern tip of the Baja California peninsula, and subsequently dissipates.[29]
18:00 UTC (10:00 a.m. PST) at 15°00′N122°54′W / 15.0°N 122.9°W / 15.0; -122.9 (Ramon reaches its peak intensity.) – Tropical Storm Ramon reaches its peak intensity, with maximum sustained winds of 45 mph (75 km/h) and a minimum central pressure of 1002 mbar (29.59 inHg),[32] roughly 1,000 mi (1,610 km) west-southwest of the southern tip of the Baja California peninsula.[33]
^Denotes number of days Hurricane Dora existed in the Eastern and Central Pacific basins, before crossing over into the Western Pacific basin.
^Beatriz formed from the same tropical wave that had previously spawned Atlantic Tropical Storm Bret.[6]
^Due to the threat the developing system posed to southwestern Mexico, the National Hurricane Center initiated advisories on it, designating it Potential Tropical Cyclone Two-E at 03:00 UTC on June 29.[7]
^The position is as of 18:00 UTC (8:00 a.m. HST) on August 6.[10]
^Due to the threat the developing system posed to southern Mexico, the National Hurricane Center initiated advisories on it, designating it Potential Tropical Cyclone Sixteen-E at 03:00 UTC on October 8 (10:00 p.m. CDT on October 7).[24]
^Otis was the first Pacific hurricane on record to make landfall at Category 5 intensity, thus becoming the strongest hurricane to make landfall on the Pacific coast of Mexico.[28]
^On November 5, daylight saving time ended in most areas of the basin, which resulted in the gap between UTC and local time widening by one hour. Hawaii was not affected; the state has not observed daylight saving time since 1945.[30][31]
