Current Snapshot

The Pacific Disaster Center’s (PDC Global) Wednesday, March 27, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 20S (Gamane)…is located approximately 309 NM north-northeast of Antananarivo, Madagascar

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 20S (Gamane)

According to the JTWC warning number 5, sustained winds are 40 knots…with gusts to near 55 knots

Animated multi-spectral satellite imagery depicts tropical cyclone 20S (Gamane) as over land in northern Madagascar. TC 20S has become less organized with convection beginning to disperse around the obscured low-level circulation center as
frictional effects start to take a toll on the system.

The current environment is assessed as unfavorable characterized by land interaction and dry air being entrained into the system. The upper-level environment is, in contrast, assessed as favorable with strong poleward outflow aloft (aided by an upper-level jet stream maximum to the south) and low (10-15 knot) vertical wind shear. These factors are not enough to outweigh the land interaction and dry air presence though.

TC 20S is forecast to begin a southward track through 24 hours as it rounds the western periphery of ridge to the east and the steering pattern becomes more defined. After 24 hours, TC 20S is expected to start on a southeastward track as the ridge propagates eastward. The system is anticipated to emerge back over water between 36 and 48 hours. TC 20S is forecast to maintain the southeastward track through the remainder of the forecast period.

The JTWC intensity forecast has the system continuing to weaken as a result of frictional effects and dry air over Madagascar entering the system through 36 hours. Near 48 hours, the system is forecast to re-intensify to 45 knots as it loses the land effects that are hindering it, and shear remains relatively low (15-20 knots).

TC Gamane is forecast to maintain 45 knots through 72 hours as vertical wind shear is not expected to reach high values by that time. Around 96 hours, the system is forecast to begin subtropical transition (which will be complete by 120 hours) and vertical wind shear values will rise to near 30 knots along with decreasing relative humidity values. In response, the JTWC intensity forecast has TC 20S weakening to 40 knots at 96 hours and 35 knots near 120 hours.