On November 23, 2019, a low pressure system developed to the southeast of Guam.
It then began to show signs of development and earned a defined circulation, developing into a tropical depression on November 25, with the JTWC assigning it as 29W. The depression then began to develop banding features to the northeast of its center, confirming intensification and allowing it to earn the name Kammuri (which is a Japanese name for Corona Borealis).
Kammuri then passed south of Guam, and further intensified into a severe tropical storm on November 27, and then into a typhoon the next day.
As the weak typhoon continued west, upwelling of itself due to its quasi-stationary movement combined with moderate wind shear hindered significant intensification of Kammuri over the next three days.
It eventually entered the Philippine Area of Responsibility (PAR) with PAGASA assigning the name Tisoy on November 30.
After entering the PAGASA's area of responsibility, Kammuri began to show signs of intensification again, and PAGASA noted the possibility of Kammuri making landfall in the Philippines as a somewhat powerful typhoon.
After very slowly moving west and on approach to the Philippines, the system began to accelerate towards the Philippines and then began to rapidly intensify by the time it came within 200 miles of the coast of Catanduanes, due to the lowering of wind shear and increasing ocean heat content; all of which combined to counteract the upwelling.
It became a category 2 typhoon and soon after, a category 3 typhoon.
Kammuri reached its peak intensity as a low-end category 4-equivalent typhoon on 07:00 UTC on December 2, and PAGASA reported that Kammuri had made its first landfall over Gubat, Sorsogon at 11:00 pm, 2 December, very shortly after reaching its peak intensity.

Through midnight and early morning of December 3, Kammuri crossed the Bicol Region and weakened due to land interaction.
It made another landfall at 4:00 am PST over San Pascual town in Burias Island.
Moving in a generally westward direction, Kammuri weakened into a Category 3 after land interaction and developed a new eye, moving very close to the Bondoc Peninsula before making its third and fourth landfalls at 8:30 am PST over Torrijos, Marinduque and at 12:30 pm PST over Naujan, Oriental Mindoro, respectively.
Continued land interaction weakened Kammuri to a Category 2-equivalent typhoon before it exited the Philippine landmass.
The center of the typhoon was reported to be over the Mindoro Strait by late afternoon.
Soon after, the system continued to weaken and became a Category 1-equivalent typhoon as it entered the South China Sea.
Kammuri's structure then began to suffer, with wind shear tearing apart convection on the western portion of the storm as it weakened back into a tropical storm while drifting over the South China Sea.
By 11:00 am PST, December 5, PAGASA issued its last bulletin on Kammuri as it exited the PAR.
Kammuri lost its inner rainbands and its low-level circulation center became exposed to high wind shear, causing the system to dissipate on December 6 with the JMA issuing its final advisory on the system.
On November 23, 2019, a low pressure system developed to the southeast of Guam. It then began to show signs of development and earned a defined circulation, developing into a tropical depression on November 25, with the JTWC assigning it as 29W. The depression then began to develop banding features to the northeast of its center, confirming intensification and allowing it to earn the name Kammuri (which is a Japanese name for Corona Borealis). Kammuri then passed south of Guam, and further intensified into a severe tropical storm on November 27, and then into a typhoon the next day. As the weak typhoon continued west, upwelling of itself due to its quasi-stationary movement combined with moderate wind shear hindered significant intensification of Kammuri over the next three days. It eventually entered the Philippine Area of Responsibility (PAR) with PAGASA assigning the name Tisoy on November 30. After entering the PAGASA's area of responsibility, Kammuri began to show signs of intensification again, and PAGASA noted the possibility of Kammuri making landfall in the Philippines as a somewhat powerful typhoon. After very slowly moving west and on approach to the Philippines, the system began to accelerate towards the Philippines and then began to rapidly intensify by the time it came within 200 miles of the coast of Catanduanes, due to the lowering of wind shear and increasing ocean heat content; all of which combined to counteract the upwelling. It became a category 2 typhoon and soon after, a category 3 typhoon. Kammuri reached its peak intensity as a low-end category 4-equivalent typhoon on 07:00 UTC on December 2, and PAGASA reported that Kammuri had made its first landfall over Gubat, Sorsogon at 11:00 pm, 2 December, very shortly after reaching its peak intensity.
Through midnight and early morning of December 3, Kammuri crossed the Bicol Region and weakened due to land interaction. It made another landfall at 4:00 am PST over San Pascual town in Burias Island. Moving in a generally westward direction, Kammuri weakened into a Category 3 after land interaction and developed a new eye, moving very close to the Bondoc Peninsula before making its third and fourth landfalls at 8:30 am PST over Torrijos, Marinduque and at 12:30 pm PST over Naujan, Oriental Mindoro, respectively. Continued land interaction weakened Kammuri to a Category 2-equivalent typhoon before it exited the Philippine landmass. The center of the typhoon was reported to be over the Mindoro Strait by late afternoon. Soon after, the system continued to weaken and became a Category 1-equivalent typhoon as it entered the South China Sea. Kammuri's structure then began to suffer, with wind shear tearing apart convection on the western portion of the storm as it weakened back into a tropical storm while drifting over the South China Sea. By 11:00 am PST, December 5, PAGASA issued its last bulletin on Kammuri as it exited the PAR. Kammuri lost its inner rainbands and its low-level circulation center became exposed to high wind shear, causing the system to dissipate on December 6 with the JMA issuing its final advisory on the system.
Typhoon Kammuri