Hurricane Ava (1973)

Hurricane Ava

Category 5 major hurricane (SSHWS/NWS)
Satellite image of Hurricane Ava
Formed	June 2, 1973
Dissipated	June 12, 1973
Highest winds	1-minute sustained: 160 mph (260 km/h)
Lowest pressure	915 mbar (hPa); 27.02 inHg (fifth-lowest in the eastern Pacific)
Fatalities	None
Damage	None
Areas affected	Southern California
Part of the 1973 Pacific hurricane season

Hurricane Ava was one of the strongest tropical cyclones ever recorded in the northeastern Pacific Ocean. It was the first named storm of the 1973 Pacific hurricane season. Forming in early June, Hurricane Ava eventually reached Category 5 intensity on the Saffir-Simpson Hurricane Scale, the first Pacific hurricane to do so in June and the earliest ever in a season. Its central pressure made it the most intense known Pacific hurricane at the time. Despite its intensity, Hurricane Ava stayed at sea without significant impact.

Ava was given the most advanced measurement and reconnaissance available at the time. Recon flights were conducted and meteorological equipment was tested. The hurricane was also photographed from space by satellites and Skylab astronauts.

On June 2, 1973, a tropical depression formed about 250 miles (400 km) south of Salina Cruz, Oaxaca. It started out nearly stationary, and became a tropical storm late on the same day it formed, the first named storm of the 1973 Pacific hurricane season. Ava then slowly moved westwards away from Mexico and became a hurricane on June 3. Ava became a major hurricane on the afternoon of June 5. The next day, a United States Air Force recon flight measured a wind speed of 150 miles per hour (240 kilometres per hour) and a central pressure of 915 millibars (27.0 inches of mercury). These measurements made Hurricane Ava by far the most intense storm of the season.

At its peak, Hurricane Ava had winds of 160 mph (260 km/h). These winds made it a Category 5 on the Saffir-Simpson Hurricane Scale, the highest possible category and the first Category 5 since the 1959 season. Ava was also a hurricane with windspeeds rapidly increasing the closer to the eye they were measured. Over a distance of 4 mi (6.4 km), wind speeds increased from 70 mph (110 km/h) to 158 mph (254 km/h), and they increased from 105 to 158 mph (169 to 254 km/h) over half that distance. The reading of 915 mbar (27.0 inHg) was roughly 100 mbar (3.0 inHg) lower than the ambient environment far from the storm.