Tropical Cyclone 11S / Tropical Cyclone 12 (Elvis) / Invest 96P / Invest 99S- Pacific
Thursday, January 30, 2025

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, January 30, 2025, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 11S is located approximately 590 NM south-southwest of Diego Garcia

Tropical Cyclone 12S (Elvis) is located approximately 619 NM east-northeast of Port Louis, Mauritius

 

Northeast Pacific Ocean: There are no Tropical Cyclones

The last regularly scheduled Tropical Cyclone Activity Report of the 2024 eastern North Pacific Hurricane Season has been issued. Routine issuance of this section of the PDC product will resume on May 15, 2025. During the off-season, Special Tropical Weather Outlooks will be issued as conditions warrant by the NHC.

Central Pacific Ocean: There are no Tropical Cyclones

The 2024 central North Pacific hurricane season has ended. As such, the final routine Tropical Cyclone Activity Report for the 2024 season has been issued. Routine issuance of this section of the PDC product will resume on June 1, 2025. During the off-season, Special Tropical Weather Outlooks will be issued as conditions warrant by the CPHC.

 

Western Pacific, Indian Ocean, and adjacent Seas: 

South Indian Ocean

Tropical Cyclone 11S

According to the JTWC warning number 6, sustained winds were 35 knots with gusts to 45 knots

Tropical cyclone (tc) 11S (eleven) is struggling to maintain tropical storm intensity, under the pernicious influence of persistent easterly shear and dry air intrusion. Animated multi-spectral satellite imagery (msi) shows that the strong convective activity that was previously over the low level circulation center (llcc) has since been blown off to the west by 20-25 knots of easterly shear, leaving behind a fully exposed llcc.

A microwave image revealed the well-defined nature of the banding features wrapping into the llcc, Albeit completely limited to the lower-levels of the atmosphere. Additionally, the microwave imagery revealed a deep wedge of dry air extending across the entire northern perimeter of the circulation and starting to wrap into the eastern perimeter.

The environment is marginal, with warm sea surface temperatures and moderate poleward and equatorward outflow being offset by strong easterly shear and dry air intrusion.

TC 11S will track generally westward along the northwestern periphery of the deep str for the next 12 to 18 hours.A  weakness in the ridging pattern to the south will result in weakening in the steering gradient, allowing the system to slow down a few knots through about 24 hours. A new deep-layer str center moves eastward to a position southeast of the Mascarenes after 24 hours, which will tighten up the gradient, allowing TC 11s to once again pick up speed. After 36 hours, as the ridge moves to the south of TC 11S, it will turn onto a more southwestward track and maintain this motion vector through about 72 hours. The system is forecast to track just north of Mauritius around 72 hours, then turn westward once again as it passes north of La Reunion by 96 hours.

In terms of intensity, the system will continue to struggle against the easterly shear and dry air, which are expected to persist for the next 36 to 48 hours. Momentum conservation and brief bursts of convection are expected to lead to a steady 35 knot intensity during this period, Though there is about an equal chance that the system will weaken to less than 35 knots during this time frame. Both the global and mesoscale models predict the shear to drop off significantly after 48 hours, coincident with a slight increase in sea surface temperatures and a general moistening of the environment. If the system can make it through the next 48 hours, it is likely to re-intensify as it passes the Mascarenes and heads towards Madagascar, where it will find a much more favorable environment.

 

Tropical Cyclone 12S (Elvis)

According to the JTWC warning number 4, sustained winds were 40 knots with gusts to 50 knots

Animated multi-spectral satellite imagery depicts a very compact low level circulation center (llcc), and a resurgence of deep convective activity around the llcc over the past six hours. The bulk of the convection is confined to the southwestern quadrant of the llcc, the convection is starting to wane a bit, revealing the tight inner spiral of the llcc.

The system lies over relatively warm waters, which are continuing to provide ample energy flux to support intensification. while shear is starting to pick up a bit, the system is situated ahead of a deep 200mb trough and at the base of a strong jet maximum, leading to a significant uptick in poleward outflow, which is offsetting the shear. 12S is forecast to track southeastward for the duration of the forecast period, along the western side of a deep-layer str centered to the east, with no significant changes from the previous forecast.

The negative effects of the increasing shear are expected to dominate the robust outflow by 24 hours, and the system will begin to slowly weaken after this point. At the same time, TC 12S will begin extratropical transition (ett) as it becomes embedded under 500mb trough axis and works under the 200mb jet max. ETT is expected to be wrapped up no later than  48 hours, with Elvis leaving the building as a gale-force extratropical low.

 

Southwest Pacific Ocean

>>> There’s an area of disturbed weather being referred to as Invest 96P, which is located approximately 194 NM southeast of Cairns, Australia

Animated multi-spectral satellite imagery depicts a poorly organized low level circulation center with weak and disorganized convection. The low level circulation center (llcc) has been re-positioned into a relatively cloud free area surrounded by tightly curved banding. The new llcc is in good agreement with GFS fields and is indicative of an immature circulation that has been moving erratically thus far.

Environmental analysis reveals that Invest 96P is in a favorable environment for further development with good equatorward outflow aloft, warm sea surface temperatures, and low (5-10 knot) vertical wind shear.

Maximum sustained surface winds are estimated at 18 to 23 knots.

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

 

South Indian Ocean

>>> There’s a second area of disturbed weather being referred to as Invest 99S, which is located approximately 243 NM south-southwest of Christmas Island  

Animated multi-spectral satellite imagery and a microwave image depict an area of flaring convection, with fragmented rain bands beginning to organize around a weakly-defined low level circulation center (llcc). 

Environmental analysis reveals that Invest 99S is in a favorable environment for further development with, good equatorward outflow aloft, warm sea surface temperatures, and low to moderate (15-20 knot) vertical wind shear. 

Global models are in good agreement that Invest 99S will generally track southwestward over the next 48 hours as the system continues to consolidate. 

Maximum sustained surface winds are estimated at 20 to 25 knots. 

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