Current Snapshot

The Pacific Disaster Center’s (PDC Global) Tuesday, March 26, 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 390 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 3, sustained winds are 90 knots…with gusts to near 110 knots

TC 20S (Gamane) has quickly consolidated over the past 12 hours with a 20 knot increase in intensity over that interval.

Animated multi-spectral satellite imagery depicts tropical cyclone 20S (Gamane) as a compact system with persistent deep convection over the center of an obscured low-level circulation (llcc). A pronounced convective band to the east of the llcc can be seen in the animated imagery surrounding the circulation and extending into the northern periphery. An image reveals 40-45 knots in the southern semicircle of the llcc, and TC 20S has continued to structurally improve.

The current environment is assessed as favorable characterized by strong poleward outflow aloft, very low (0-5 knot) vertical wind shear (vws), and warm sea surface temperatures. The only possible hindrance to the system is its proximity to land with potential friction induced on the lower levels.

TC 18S is forecast to begin tracking south-southwestward over the next 24 hours as it exits the competing steering environment and tracks along the western periphery of a subtropical ridge (str) to the east. After 24 hours, TC 20S is forecast to track southward through 48 hours as it rounds the str. After 48 hours, the system is expected to begin a southeastward track as the str propagates to the east. TC 20S is then forecast to continue on the southeastward track through the remainder of the forecast period.

Regarding the JTWC intensity forecast, TC 20S is forecast to continue to intensify to a peak of 85 knots near 24 hours as vws values continue to be low and divergence aloft continues to be strong. TC 20S is forecast to maintain 85 knots through 36 hours, and then weaken to 70 knots near 48 hours in response to land interaction along the northeastern coast of Madagascar. After 48 hours, the system is forecast to continue weakening to 60 knots near 72 hours, 55 knots near 96 hours, and 45 knots near 120 hours. This is due predominately to increasing vws values and dry air beginning to entrain into the system from the west.