Tropical Cyclone 17S (Filipo) / Tropical Cyclone 18S / Invest 93P
Monday, March 11, 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) Monday, March 11, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 17S (Filipo)…is located approximately 264 NM west-northwest of Europa Island.

Tropical Cyclone 18S…is located approximately 725 NM northwest 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 17S (Filipo)

According to the JTWC warning number 3, sustained winds were 60 knots…with gusts to near 75 knots

Animated multi-spectral satellite imagery depicts a consolidating system with a central dense overcast feature and improved deep convective banding. A partial microwave image reveals tightly-curved banding over the southeastern quadrant reflecting the rapid consolidation of the low-level circulation over the past six hours.

Environmental conditions are favorable with radial outflow and enhanced poleward outflow, low vertical wind shear (vws) and warm sea surface temperature values. However, frictional effects are beginning to negatively impact the outer banding along the western periphery of the system.

Tropical cyclone 17S is forecast to track generally west-southwestward through 24 hours along the northwestern periphery of the ridge, with landfall over the Mozambique coast near 20 hours. After 24 hours, the system will recurve around the western periphery of the ridge and begin interacting with the subtropical westerlies and associated long wave trough by 48 hours.

After 48 hours, the system will re-emerge over water and begin to re-intensify while undergoing subtropical and then extratropical transition (ett) through interaction with the mid-latitude westerlies. TC 17S will complete ett by 96 hours as it tracks under the polar front jet stream and gains frontal characteristics.


Tropical Cyclone 18S

According to the JTWC warning number 4, sustained winds were 35 knots…with gusts to near 45 knots

Tropical cyclone 18S has continued to struggle to develop due to persistent high (30-40 knots) easterly vertical wind shear as evidenced in the animated satellite imagery. The fully exposed low-level circulation (llc) has become completely obscured over the last six hours by flaring convection along the western periphery of the circulation center.

However, imagery has recently revealed a broad, exposed surface circulation. Deep convection has remained isolated to the western edge of the llc, while low-level banding and a broad center are also evident in microwave imagery.

TC 18S is forecast to track east-southeastward through 72 hours under the strong steering influence of the ridge. After 72 hours, the system will slow, possibly becoming quasi-stationary as the steering influence gradually transitions to a building ridge over Australia.

The system is expected to turn south-southwestward by 120 hours along the northern periphery of the aforementioned ridge within a competing steering environment.

The system will intensify slowly through 72 hours due to persistent high (25-35 knot) easterly vertical wind shear. After 72 hours, the system will intensify at a slightly quicker rate, however, the peak intensity will remain limited due to the lack of a poleward outflow mechanism.


>>> According to the JTWC, there’s an area of disturbed weather under investigation, being referred to as the Invest 93P…which is located approximately 487 NM east of Darwin, Australia.

Enhanced infrared imagery depicts a broad area of flaring convection, with a weakly defined llcc.

Upper-level analysis indicates 93P is in a favorable environment for development with low (15-20 knot) vertical wind shear, warm sea surface temperatures, coupled with enhanced equatorward outflow.

Global models are in good agreement that 93P will steadily deepen as it develops under favorable conditions. Global models have 93P advancing east-southeast within the next 24 hours, briefly tracking over land, then re-intensifies as it maintains an east-southeastward track into the Coral Sea over the next 36 hours.

Maximum sustained surface winds are estimated at 13 to 17 knots.

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