Archive | June 13, 2012

Tropical Storm Guchol Afternoon Update June 13, 2012

Tropical Storm Guchol strengthens slightly as it moves north of Yap. The storm was last located approximately 140km northeast of Yap Island. Maximum sustained winds have increased to 75kph with gusts reaching up to 100kph. TS Guchol is currently moving to the west northwest at a speed of 20kph.

Tropical Storm Warning remains in effect for Fais, Ulithi, and Yap Island. Stormy conditions will continue for these areas throughout tonight. Yap Airport already reporting continuous light to moderate rains, winds of up to 40kph, and continuous decrease in atmospheric pressure. Since Guchol will be passing to the north of the island, we expect winds of below tropical-storm force although occasional gusts of 60 to even 80kph is possible tonight. Rains of up to 100mm are possible as well. Furthermore, rough seas will continue tonight and for the next 2 days. Rains and gusty winds should slowly taper off later tomorrow.

Microwave image from the SSMI-S (NRLMRY)

We are starting to see improvements with Tropical Storm Guchol’s structure. The microwave image above shows the banding wrapping around the center of circulation. Furthermore, the image also hints at an eyewall-like feature that is starting to form. We are still unsure if this is a continuous trend or just a burst of intensification given the current paltry IR presentation. Nevertheless, overall conditions in the region are still favorable for continued intensification over the next few days.

The turn to the west northwest in the past 3 hours, as well as an apparent increase in forward speed, are signs of the effects of the subtropical ridge.While we’re still unsure about the long-term track of Guchol, the recent turn in movement is a good sign for Luzon but definitely sounds ominous for Taiwan and the Japanese Islands. Tropical Storm Guchol will continue moving west northwestward and is forecast to enter the Philippine Area of Responsibility by Thursday evening; PAGASA will assign the local name ‘Butchoy’. Wind shear should weaken across the Philippine Sea, and with warm sea temperatures, TS Guchol should intensify at a faster pace. Barring any sudden weakening,  Guchol could become a typhoon by as early as Friday morning.

JMA 5-Day Track Forecast

Recent computer model consensus is starting to become more closely-packed with a track showing a turn to the northwest by Friday which should keep it away from Luzon. And as you can see with the JMA Forecast above, track seems to be putting it to the north, away from the Philippines but into the Japanese Islands. With that said, Eastern Luzon, Taiwan, and the Yaeyama Islands should still be on the lookout, which are all under the uncertainty cone, as we continue to track this system. Right now however, chances are increasing for a possible stormy weekend across Yaeyama and Miyako Islands, as well as in Taiwan and Northeastern Luzon.

-WxCaster PAT