Severe Tropical Storm Conson, known in the Philippines as Typhoon Jolina, was a strong tropical cyclone that impacted the central Philippines and Vietnam during the 2021 Pacific typhoon season. Being the thirteenth named storm of the said event, Conson originated as a low-pressure area first monitored approximately west of Guam. It formed as a tropical depression over the Pacific Ocean on September 5, 2021. As it formed within the Philippine Area of Responsibility, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) named the storm Jolina. Over the next day, it intensified into a tropical storm and was named Conson by the Japan Meteorological Agency (JMA). As the storm neared Samar Island, it intensified into a severe tropical storm, and later into a typhoon according to the PAGASA prior to its first landfall in Eastern Samar. The storm retained its strength as it crossed Visayas and later Calabarzon before weakening over Manila Bay prior to its final landfall in Bataan. It subsequently emerged into the South China Sea where it struggled to reintensify further. It then weakened into a tropical depression just offshore of Vietnam before moving ashore near Da Nang. It then rapidly weakened before dissipating on September 13.
The National Disaster Risk Reduction and Management Council in the Philippines reported 20 deaths, 23 injuries and 12 missing individuals. Agricultural and infrastructural damages in the Philippines are estimated at ₱1.59 billion (US$31.8 million).
Meteorological history
At 06:00 UTC of September 5, the United States Joint Typhoon Warning Center (JTWC) started to monitor a tropical disturbance in the Philippine Sea , located about to the east-southeast of Legazpi, Albay. At that time, multispectral animated satellite imagery revealed a low-level circulation center with cloud lines circling along the feature. The system was also in an area conducive for further development, with poleward outflow, favorable wind shear, and sea surface temperatures. Over the next few hours, it gained organization as it remained stationary. At 18:00 UTC that day, the Japan Meteorological Agency upgraded the system to a tropical depression, followed simultaneously with the PAGASA's designation of the storm as Tropical Depression Jolina as it was under the agency's area of responsibility. This made the storm the tenth tropical cyclone in the region for the season. Meanwhile, the JTWC issued a Tropical Cyclone Formation Alert (TCFA) at 23:30 UTC as a circulation was now evident along the system and an organizing convective band to its south-southeast.
The same agency further upgraded the storm to a tropical depression on the next day as it further consolidated, with a persistent area of thunderstorms over an obscured low level circulation center (LLCC). Moving northwestward under the periphery of a subtropical ridge to the northeast, its organization continued to improve with an eye feature developing and at 06:00 UTC that day, the depression strengthened to a tropical storm according to the estimates of JMA and PAGASA, with the former naming it Conson. The JTWC did the same, three hours later. At 09:00 UTC (17:00 PHT), the PAGASA reported that the system further intensified to a severe tropical storm while nearing Samar Island. Over the next hours, its convection further expanded to the east from the southeast and as a result the JMA upgraded the system as well, two hours later. It subsequently intensified to a typhoon, prior to landfall over Hernani, Eastern Samar at 13:00 UTC (22:00 PHT). Conson then traversed Visayas, making additional landfalls in Daram, Santo Niño, Almagro, and Tagapul-an in Samar. The system continued consolidating while over Samar which allowed it to form a small microwave eye.
The following day, it made another landfall in Dimasalang, Masbate (2:00 UTC). Land interaction while the storm was above Masbate slightly weakened Conson as its LLCC became ragged. Traversing the Sibuyan Sea allowed Conson to briefly form a well-defined radar eye while maintaining strength. The system then made another landfall in Torrijos, Marinduque. On September 8, the storm made another landfall in San Juan, Batangas. Despite interaction with land in South Luzon, the system maintained strength while traversing Calabarzon. It then weakened as its LLCC became disorganized over Manila Bay, with the PAGASA downgrading it into a tropical storm. Conson made its last landfall in the Philippines in Mariveles, Bataan at 09:00 UTC (17:00 PHT). It later strengthened to a severe tropical storm once again at 12:00 UTC before emerging into the South China Sea, about three hours later.