Invest 93W Heading Toward the Philippines

Although the global tropics are generally fairly quiet at the moment, there are still a few areas of interest. In particular, Invest 93W is located in the West Pacific east of the Philippines. The West Pacific remains convectively favored in an active phase of the Madden-Julian Oscillation (MJO), and this system will be worth keeping an eye on as it moves towards the west in the coming days. Currently, most Google DeepMind members (Figure 1) keep it fairly weak as it crosses the Philippines. However, recent examples have shown us that flooding can be the most deadly and destructive hazard for landfalling TCs, and it doesn’t take a strong storm to cause major flooding issues. In addition, there are some members that intensify it into a typhoon, potentially a strong one.

The main steering influence for 93W over the next few days will be a narrow ridge overhead and to the NE, nudging it Southwest and then West in the direction of the Philippines (Figure 2).

One of the biggest obstacles to significant intensification of 93W will be easterly shear. The upper-level anticyclone currently overhead will become displaced as the system moves off to the west (Figure 3), bringing 20-25 knots of upper level east/southeast shear over the storm. This shear will probably prevent it from becoming aligned for a while, and will limit rapid intensification chances.

Some dry air wrapping around from the west side (Figure 4) could also slow the intensification as the storm approaches the Philippines, if it makes its way into the core.

As mentioned above, however, even a weaker storm has the potential to produce heavy rain (Figure 5), as the TC brings in moisture from the deep tropics and interacts with the right entrance region of the Jet to the north. This will need to be watched closely in the Philippines for potential flooding issues.