Kalmaegi moving towards Vietnam, 32W spinning up and heading towards the Philippines

The West Pacific remains active with two systems spinning westward and threatening land areas.

Typhoon Kalmaegi

Typhoon Kalmaegi is moving into the South China Sea after passing through the Philippines and causing lots of flooding issues, including at least 85 deaths. This is another example that goes to show why water is typically the deadliest threat from tropical cyclones.

The storm has a fairly compact inner core, which could lead to some rapid intensification, and some Google DeepMind/FNV3 members intensify it into a Category 3-4 equivalent typhoon prior to landfall (Figure 1).

Models continue to show that the easterly shear that has slowed the storm down since its inception will stay with Kalmaegi as it moves across the South China Sea, which will continue to act as an impediment to intensification and keep it from reaching its full thermodynamic potential (Figure 2). Still, it is likely to be a significant typhoon for coastal Vietnam, with storm surge, wind damage, and heavy rain all posing major threats. As we just saw in the Philippines, it doesn’t take a supertyphoon to cause immense flooding and devastation.

Tropical Depression 32W

The other system of interest, 32W, is slowly coming together in the West Pacific East of the Philippines. It is a very broad system currently, with healthy outflow and lots of spiral bands but not much inner-core convection yet. Once it develops an inner core, the environment seems very favorable for rapid intensification. Most DeepMind/FNV3 members make it a supertyphoon, quite a few in the 150-160 knot range.

In addition, other AI models are showing quite a bit of intensification. AIFS brings the system down to 952 hPa (Figure 4), which is quite strong for a low-resolution AI model without any intensity adjustment like what DeepMind/FNV3 does.

The fact that even AI models are showing significant intensification with pressures indicative of a major typhoon goes to show how favorable the large-scale environment is, with very warm sea surface temperatures fueling the storm and a large anticyclone aloft enhancing upper-level outflow (Figure 5).

The system appears quite likely to directly impact the Philippines as a strong typhoon, as the ridge to the north will keep it moving west-northwest for the next several days. In the medium range, it will likely turn north ahead of a trough, and could impact Taiwan though likely in a weakened state. Still, heavy rain could be a significant threat, especially since the storm will be in the entrance region of a jet streak, which favors synoptic enhancement of lift and rainfall (Figure 6). Folks in Luzon and nearby islands should take this storm very seriously, make preparations, and listen to guidance from local officials.