Current Snapshot

The Pacific Disaster Center’s (PDC Global) Sunday, April 7, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 21S (Olga)…is located approximately 505 NM northeast of Learmonth, Australia

Northeast Pacific Ocean:

The North Pacific hurricane season officially ended on November 30, 2023. Routine issuance of the Tropical Weather Outlook will resume on May 15, 2024. During the off-season, Special Tropical Weather Outlooks will be issued as conditions warrant.

The eastern Pacific basin hurricane season was above normal, with 17 named storms, of which 10 were hurricanes and eight of those major hurricanes.

From August 16 to 21, Tropical Storm Hilary brought widespread heavy rainfall and flooding to Southern California, with some areas receiving up to 600% of their normal August rainfall. Hilary resulted in the first ever issuance of Tropical Storm Watches and Warnings for the Southern California coastline by NOAA’s National Hurricane Center. In addition, the Center distributed key hazard focused messages for Hilary in Spanish through the agency’s new language translation project.

Hurricane Otis made landfall near Acapulco, Mexico, on October 25 as a category-5 hurricane, with sustained winds of 165 mph. Otis holds the record as the strongest land falling hurricane in the eastern Pacific, after undergoing rapid intensification in which wind speeds increased by 115 mph in 24 hours.

Central North Pacific:

The central North Pacific hurricane season officially ended on November 30, 2023. Routine issuance of the Tropical Weather Outlook will resume on June 1, 2024. During the off-season, Special Tropical Weather Outlooks will be issued as conditions warrant.

The central Pacific basin had a near-normal season with four tropical systems traversing the basin.

Hurricane Dora, a category-4 storm, passed south of Hawaii in early August, marking the first major hurricane in the central Pacific basin since 2020. The strong gradient between a high pressure system to the north and Dora to the south was a contributing factor to the wind-driven, fast-moving wildfires in Hawaii.

Western Pacific, Indian Ocean and adjacent Seas

South Indian Ocean…

Tropical Cyclone 21S (Olga)

According to the JTWC warning number 8, sustained winds are 120 knots…with gusts to near 145 knots

Tropical cyclone 21S has undergone extreme rapid intensification over the past 24 hours, from 50 knots to 100 knots.

Animated multi-spectral satellite imagery depicts asymmetric core convection surrounding an 8 NM eye. Due to the extensive dry air around the periphery of the system, and a microwave image reveals a compact convective core, with limited banding over the southern quadrant.

Environmental conditions are favorable, with low vertical wind shear, strong poleward outflow and warm sea surface temperature values. However, as expected, increasing northwesterly vertical wind shear is beginning to impinge on the western periphery of the system degrading westward outflow as indicated in the animated water vapor imagery. Additionally, dry air is entraining into the northeastern quadrant of the system.

TC 21S will continue tracking southwestward to west-southwestward along the northwestern periphery of the southern ridge through 96 hours while rapidly weakening. The peak intensity is likely occurring now or within the next six hours, with increasing northwesterly vertical wind shear of 25 to 35 knots commencing near 6 through 12 hours. additionally, significant dry air entrainment will begin to envelop the system within the next 12 hours.

After 12 hours, TC Olga will weaken rapidly as vertical wind shear increases to 35 to 45 knots then even stronger (50 to 70 knots) values after 48 hours as the system tracks under strong subtropical westerlies. At the same time, the environment will rapidly transition to very dry conditions, which will lead to dissipation no later than 96 hours.