Tropical Cyclone 18S / Invest 94S
Thursday, March 14, 2024

Current Snapshot

For all the latest updates visit: DisasterAWARE

By PDC’s Senior Weather
Specialist Glenn James

The Pacific Disaster Center’s (PDC Global) Thursday, March 14, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 18S…is located approximately 283 NM north-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 18S

According to the JTWC warning number 16, sustained winds were 35 knots…with gusts to near 45 knots

Tropical cyclone 18S has shown signs of increased consolidation as vertical wind shear has decreased in close proximity to the central core, and the once fully-exposed center has become completely obscured by increased flaring convection over the low-level circulation center, as revealed in the animated enhanced infrared satellite imagery.

Moderate equatorward outflow is now evident over the surface circulation, as upper-level outflow has continued to aid in the overall consolidation of the system throughout the last six hours.

TC 18S is forecast to track southeastward through 12 hours. However, the system is expected to continue slowing down and gradually turn southward to southwestward through 42 hours as the aforementioned westward building ridge to the south becomes the dominant steering influence.

TC 18S is forecast to maintain weak tropical storm strength through 48 hours due to the marginal upper-level conditions. After 48 hours, vertical wind shear is expected to continue decreasing, allowing the system to consolidate further. After 48 hours, TC 18S will track slowly south-southwestward toward a break in the ridge steering pattern associated with an approaching shortwave trough and frontal system.

After 90 hours, a strong low-level high is expected to build to the south over western Australia, effectively blocking and slowing poleward progression. After 66 hours, environmental conditions appear increasingly conducive, with low vertical wind shear and improving poleward outflow into the mid-latitude equatorward extending shortwave trough, which will result in moderate intensification to a peak intensity of 70 knots by 96 hours and through the remainder of the forecast period.


>>> According to the JTWC, there’s an area of disturbed weather under investigation, being referred to as the Invest 94S…which is located approximately 56 NM southwest of Gove AP, Australia.

Animated multi-spectral satellite imagery depicts a partially exposed llc with
convection building over the circulation. A recent surface observation valid at 150038z reports winds from the north-northwest at 16 knots.

Environmental analysis indicates 94S is in a moderately favorable environment for development with good divergence aloft and warm sea surface temperatures offset by high (25-30 knot) vertical wind shear.

Global models are in good agreement that 94s will continue to track eastward into the Gulf of Carpentaria to a more favorable environment for
development and begin intensifying in the next 24 hours.

Maximum sustained surface winds are estimated at 28 to 33 knots.

The potential for the development of a significant tropical cyclone within the next 24 hours is upgraded to high.