SA GITNA NG BAGYO: Typhoon Guchol (Butchoy) Update #15

Typhoon Guchol (Bagyong Butchoy) continues to slowly weaken as it nears Okinawa. The storm was last located roughly 250km south of Okinawa. Maximum sustained winds are now down to 195kph with gusts of up to 240kph. Guchol is now a Category 3 typhoon on the Saffir-Simpson Scale. TY Guchol is currently moving north northeastward at 30kph.

JMA has issued Storm and High Waves Warnings for Okinawa and Amami. Latest reports from the region indicate sustained winds ranging from 35 to 50kph are starting to be felt. Gusts of up to 60kph has been recorded in some places as well. Meanwhile, radar data from JMA showing outer rain bands are now affecting Okinawa and the surrounding islands. Initial rates are light (around 5mm/hr) although bands of heavier rain (10 to 15mm/hr) slowly approach from the south. For more radar images, please click HERE (JMA website).

Radar Image from JMA

Satellite images continue to show strong convective activity around the CDO. The eye has degraded and is now barely visible. Nevertheless, a microwave image (not shown here) depict a well-formed eyewall with deep convection forming all throughout. The eyewall replacement cycle finished successfully although we don't expect Guchol to intensify anymore.

IR Image from NRLMRY

Here is our short-term forecast and our Typhoon Timeline for Okinawa. Please note that this is NOT OFFICIAL! Always consult JMA for the official warnings and forecasts for your area.

Typhoon Timeline (NOT OFFICIAL!)

9pm JST: 120km southeast of Okinawa, 230km west of Daitojima. Sustained winds of 50 to 70kph possible for Okinawa; gusts of up to 120kph likely. Light to moderate rains continue to fall as well.
12am JST: 200km northeast of Okinawa, 180km northwest of Daitojima, 160km southeast of Amami. Tropical storm force winds continue for Okinawa although starting to weaken. TS-force sustained still possible for Daitojima with occasional typhoon-force gusts. Winds of 40 to 70kph starting for Amami.
3am JST: 140km east of Amami, 340km northeast of Okinawa, 250km north northwest of Daitojima. Tropical storm winds continue for Amami. Winds starting to weaken for Okinawa although occasional gusts of up to 80kph still possible. Winds starting to weaken for Daitojima as well although could still range from 60 to 100kph with gusts of up to 120kph.
6am JST: 240km northeast of Amami, 260km southeast of Kagoshima, 480km northeast of Okinawa, 390km north of Daitojima. Winds dying down for Okinawa. TS winds still likely for Amami and Daitojima. TS-force winds starting to be felt across southern and eastern portions of Kyushu.

Total rainfall amounts for Okinawa could be around 150 to 200mm, same for Amami.

Meanwhile, forecast tracks have shifted significantly for the day 2-3 portion. We are now taking Guchol towards the Shikoku/Honshu area by early Wednesday morning as a weakening Category 1 typhoon. It will then track across Kansai Region, passing through Osaka. It will then weaken to a Tropical Storm as it encounters rugged terrain. Guchol is forecast to start transitioning into an extra-tropical cyclone by Wednesday night as it moves across Chubu and then into Tohoku Region. Our latest track is keeping Guchol away from Tokyo although widespread rains are possible for Japan as Guchol interacts with the baroclinic zone. It will also pass near the Fukushima Area bringing winds of 40 to 60kph and light to moderate rains.

Forecast Track (NOT OFFICIAL!)