Tropical Update

Quieter weather regime is in place for the Philippines this week with the northerlies affecting Luzon and easterlies affecting Visayas and Mindanao. Eastern Asia is also mostly quiet and cold with chances for snow showers especially in NE China and the Korean Peninsula. Western areas of Honshu, as well as Hokkaido, in Japan will experience sea-effect snow. As for the tropics, we are currently watching two tropical disturbances: one in the South China Sea, and another in the Philippine Sea. This IR Image from NRLMRY depicts the numerous weather systems discussed in this update.

IR image from NRLMRY

The first tropical disturbance is Invest 98W which is located approximately 300km south of Vietnam in the South China Sea. An ASCAT pass earlier today suggests a developing low-level center with winds of 20 to 30kph. Wind shear is low to moderate (10-20kt). Sea surface temperatures are somewhat favorable. The system is embedded in the wind convergence that is producing showers across the South China Sea. 98W is moving westward at around 20kph and could approach the Thai-Malay Peninsula this weekend. The system has a low chance of development as noted by JTWC, as well as having little model support. Nevertheless, we do expect the disturbance to bring rains across Malaysia, Thailand, and even Cambodia and Singapore over the weekend.

VIS Image from NRLMRY showing the location of Invest 98W

The next system is 99W which is located approximately 400km southeast of Davao City. It, too, is embedded along a weak convergence that is bringing showers into Yap and Palau. While 99W's chances for development is low, it could potentially bring heavy rains across Southern Mindanao, depending on the track it takes. Right now, we have two scenarios: a tracks towards Western Papua/North Moluccas and North Sulawesi of Indonesia. The other potential track is towards the northwest into Southern and Central Mindanao. Either way, we expect rain showers to affect Davao Region starting tonight and will continue for the next 3 days. We will give you more updates with regard to the progress of this disturbance.

Finally, we have the 3-day weather forecast for cities in the Philippines. As said at the top, we expect quieter weather in the northern half of the Philippines with only slight chances for rain showers. Much of the precipitation will occur in the Southern Visayas/Mindanao region due to the wind convergence as well as the developing 99W. Please note that this is NOT OFFICIAL.

We'll have our next update on Monday, January 2, unless there's a significant development to either 98W or 99W. So this is potentially our last post for 2011. Until our next update, we hope you all have a wonderful and SAFE NEW YEAR!
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Issued (09 UTC) 5pm PhT 123011