Tropical Cyclone 18S / Tropical Cyclone 19P
Friday, March 15, 2024

Current Snapshot

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By PDC’s Senior Weather
Specialist Glenn James

The Pacific Disaster Center’s (PDC Global) Friday, March 15, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 18S…is located approximately 273 NM north of Learmonth, Australia

Tropical Cyclone 19P…is located approximately 397 NM east of Darwin, 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 19, sustained winds were 35 knots…with gusts to near 45 knots

Tropical cyclone 18S has continued to depict signs of slow consolidation with persistent deep convection and associated overshooting tops just west of the low-level circulation center (llcc). the surface center has become increasingly obscured between two convective structures just to the east and west, with observable warming tops over the last few hours as revealed in the animated enhanced infrared satellite imagery. Weak radial outflow is evident over the llcc, as upper-level outflow from associated convection continues to fuel the ongoing and slow intensification trend.

TC 18S is currently tracking west-southwestward along the northwestern periphery of the ridge located over central Australia and extending westward into the southwestern Indian Ocean (io). As the aforementioned deep-layer ridge continues to build slightly westward, TC 18S is forecast to continue its slow, meandering west-southwestward track through 36 hours. After 36 hours, a deep longwave trough will weaken the ridge steering flow, allowing for a sharp southwestward track until 72 hours. As the high in the southern io reorients eastward, TC 18S will begin a west-northwestward track along the northern periphery of the southeast trade flow through 120 hours.

As the cyclone progresses generally westward, a more conducive environment is expected as vertical wind shear remains low (10-15 knots), the system’s core maintains its moist structure, and favorable poleward outflow increases, resulting in a steady increase in intensity through 120 hours of up to 65 knots.



Tropical Cyclone 19P

According to the JTWC warning number 2, sustained winds were 40 knots…with gusts to near 50 knots

Animated satellite imagery depicts a consolidating system with deep convection increasing in areal extent, obscuring the low-level circulation center (llcc). However, animated radar imagery from the Gove airport radar depicts a fairly defined llcc just northeast of Groote Eylandt airport, with convective banding primarily over the western semicircle.

Surface observations from Groote Eylandt airport are unimpressive with winds less than 15 knots. However, surface observations from Ngayawili (12.0s 135.5e) reveal sustained westerly winds as high as 43 knots (10-minute average) over the past 12 hours. Cape Wessel (11.0s 136.7e) indicates 30 to 40 knot sustained westerly winds over the past 12 hours.

Environmental conditions are gradually improving with low to moderate vertical wind shear and expanding equatorward and poleward outflow. Sea Surface values are conducive for further development.