Current Snapshot

The Pacific Disaster Center’s (PDC Global) Sunday, March 17, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 18S…is located approximately 336 NM north-northwest of Learmonth, Australia – Final Warning

Tropical Cyclone 19P (Megan)…is located approximately 401 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 – Final Warning

According to the JTWC warning number 29, sustained winds were 30 knots…with gusts to near 40 knots

Animated enhanced infrared satellite imagery depicts tropical cyclone 18S with a slightly improved convective structure over the past 6 hours. Though flaring deep convective bursts have become more persistent, the overall structure of the system remains rather disorganized. A satellite microwave image reveals deep convection in the eastern periphery of the low-level circulation center (llcc) and convective banding wrapping into the system in the southern semicircle.

The current environment is assessed as marginal based on the weak poleward outflow aloft and dry air entraining into the system, which is offset by low (10-15 knot) vertical wind shear and warm sea surface temperatures.

TC 18S is forecast to begin tracking slowly southwestward over the next 24 hours. After 24 hours, TC 18S is forecast to track slowly northwestward through 48 hours as the system begins to feel the steering effects of the subtropical ridge (str) that propagates from the west. As the str builds to the south, the steering mechanism is expected to become much more defined and the track speed is anticipated to increase as the system tracks westward along the northern periphery of the str through the remainder of the forecast period.

TC 18S is forecast to maintain its intensity of 35 knots until 12 hours and increase to 45 knots around 48 hours due to a decrease in vertical wind shear. After 48 hours, TC 18S is forecast to begin a gradual intensification phase throughout the remainder of the forecast period in response to low vertical wind shear and the vortex moistening.

Tropical Cyclone 19P (Megan)

According to the JTWC warning number 11, sustained winds were 85 knots…with gusts to near 105 knots

Animated enhanced infrared satellite imagery depicts tropical cyclone 19P (Megan) exhibiting trochoidal motion as the system tracked generally east-northeastward over the past six hours, backtracking over previously traveled waters. A microwave image captured a well-defined microwave eye, with the corresponding image suggesting the TC vortex is well aligned vertically. A radar (sar) image reported up to 123 knots in the northwest quadrant of the system and as low as 92 knots in the southwest quadrant.

TC 19P (Megan) is forecast to track south-southwestward to southwestward following the steering influence of a weak ridge to the north to northeast. Prior to landfall near 24 hours, a favorable environment having low to moderate (10-20 knot) vertical wind shear, very warm sea surface temperatures, and moderate poleward outflow aloft (collocated with upper-level point source) leaves room for further intensification to occur through 06 hours.

Once interaction with land and frictional components begin to impact the storm, a rapid weakening trend is anticipated to start at or prior to 06 hours and continue through 72 hours as the system tracks inland. Shortly after 36 hours the primary steering influence is expected to shift from the previously mentioned ner to a str over central Australia and steer the system westward through 72 hours. Dissipation is forecast to be complete by 72 hours over northern Australia.