Friday, August 24, 2012

Typhoon Bolaven (Julian) Update #9

Typhoon Bolaven (Bagyong Julian) continues to intensify as it moves across the Philippine Sea. It was last located approximately 760km southeast of Okinawa. Bolaven is now a Category 4 Typhoon with maximum sustained winds of 215kph with gusts of up to 260kph. The system is currently moving northwestward at 15kph.

No storm warnings yet from JMA although Kadena has upgraded its TCCOR to 3. Residents in the base should start stocking up supplies and tie down any loose objects outside; much better if they are put inside to avoid debris flying during the height of the storm.

IR Image from NRLMRY

Latest satellite image shows a number of improvements with regards to the storm's structure. A 10 nautical mile pinhole eye has developed surrounded by deep convective ring. Furthermore, the poleward outflow of Bolaven has improved tremendously, while the equatorward outflow remains excellent. However, we are seeing some dry air affecting Bolaven and actually disrupting some convective activity particularly along the northern and northeastern side of the system.

Microwave Image from NRLMRY

Another aspect we are watching is the possibility of an eyewall replacement cycle (EWRC). As you can see on the image above, the eyewall is looking very established although it is small. Just outside the eyewall, another ring of strong convection is starting to form. Since the system will remain over water in the next 2 days, we could see the inner eyewall collapse with the outer one taking over in the next 24 to 36 hours. This eyewall replacement could temporarily disrupt Bolaven's intensification. Either way, we still expect this system to be a very strong Typhoon once it hits Okinawa by Sunday.

Forecast Track (NOT OFFICIAL!)

Our Forecast Track remains nearly the same and we are still expecting Bolaven to eventually make landfall in Okinawa by Sunday morning or midday. Before that, Bolaven could begin enhancing the Southwest Monsoon across Luzon and Visayas in the Philippines tomorrow so expect scattered showers there as well. Bolaven could then move near the Ryukyu Islands by Saturday afternoon. Due to the large wind field of this system, tropical storm force winds of 65kph or more could begin in Okinawa by as early as Saturday evening and will continue throughout Sunday. The peak winds are expected to be felt in the island between 6am to 2pm on Sunday; this is when Bolaven is forecast to make landfall as a Category 4. Sustained winds of up to 200kph are possible along with occasional gusts of up to 260kph.

Bolaven will then accelerate to the north and will start to weaken once it moves into the East China Sea. Cooler waters and increasing wind shear will weaken the system to a Category 2 typhoon by Monday evening. It will move 200km west of South Korea by Tuesday bringing gusty winds and heavy rains in the region. Bolaven is forecast then to make landfall in North Korea by Tuesday afternoon as a weakening Category 1 typhoon.

Bolaven is an extremely dangerous typhoon and could be Okinawa's biggest storm in years. Please prepare now, if you haven't done so already. Again, we are NOT an official agency so please continue monitoring JMA or Kadena Weather (for the base) for the latest warnings and forecasts.

We'll have another update tomorrow. Stay safe!
Issued (0930 UTC) 530pm PhT 082412

No comments:

Post a Comment