Tropical Cyclone 18S / Tropical Cyclone 19P (Megan)
Saturday, March 16, 2024

Current Snapshot

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By PDC’s Senior Weather
Specialist Glenn James

The Pacific Disaster Center’s (PDC Global) Saturday, March 16, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 18S…is located approximately 312 NM north of Learmonth, Australia

Tropical Cyclone 19P (Megan)…is located approximately 405 NM east-southeast 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 24, sustained winds were 35 knots…with gusts to near 45 knots

Animated enhanced infrared satellite imagery depicts tropical cyclone 18S with improved deep convective bursts over a broad low-level circulation center (llcc). A microwave image reveals the deep convection straddling either side of the llcc in the western and eastern quadrants of the system.

Environmental analysis indicates that TC 18S is in a marginal environment for intensification with moderate westward outflow aloft, low to moderate (15-20 knot) easterly vertical wind shear, and warm sea surface temperatures.

TC 18S is currently slowly tracking north-northwestward while located within a competing steering environment. A near equatorial ridge to the north and a subtropical ridge to the south are causing the system to drift slowly in a quasi-stationary fashion. TC 18S is forecast to maintain a weak steering mechanism over the next 48 hours. During this time there is a variety of different tracks the system could take, and the model guidance suggests that.

TC 18S is forecast to track slowly northwestward until 12 hours. After 12 hours, TC 18S is forecast to start a southwestward turn and meander southward from 24-48 hours. After 48 hours, the steering mechanism will be more defined, and the system is expected to track westward along the northern periphery of a subtropical ridge (str) for the remainder of the forecast period with track speeds increasing.

Regarding intensity, the JTWC intensity forecast has TC 18S slowly intensifying to 55 knots by 120 hours. TC 18S is anticipated to remain in a marginal environment, but as the steering pattern improves and track speeds increase, the system is expected to gradually intensify.


Tropical Cyclone 19P (Megan)

According to the JTWC warning number 7, sustained winds were 80 knots…with gusts to near 100 knots

Animated multi-spectral satellite imagery depicts tropical cyclone 19P (Megan) showing deep, persistent centralized convection mostly obscuring the assessed low-level circulation center (llcc). Noteworthy, a large cirrus canopy really blossomed out over the past six hours and completely obscured the northern periphery of the middle and lower levels. Spiral bands of deep convection fill out the western semicircle and shallow banding is observable throughout the southeastern quadrant wrapping into the llcc.

TC 19P (Megan) is forecast to track south-westward from through 36 hours following the steering influence of an extension of a near-equatorial ridge to the east-northeast.

Along-track, a favorable environment having low to moderate (10-15 knot) vertical wind shear, very warm sea surface temperatures, a moist mid level (relative humidity near 70 pct), offset by moderate divergence aloft. Outflow conditions aloft are forecast to worsen through 24 hours, which is the major restraint on the system over this interval.

However, with all other environmental factors assessed as favorable for further intensification to occur, the system is expected to intensify to peak intensity near 70 knots by around 24 hours. Landfall is anticipated to occur near 48 hours along the southern coast of the Gulf of Carpentaria. Dissipation is anticipated to occur prior to 72 hours as the system moves inland over northern Australia.