Tropical Storm Bolaven (2018)
|Tropical storm (JMA scale)|
|Tropical depression (SSHWS)|
|Formed||December 29, 2017|
|Dissipated||January 4, 2018|
10-minute sustained: 65 km/h (40 mph) |
1-minute sustained: 55 km/h (35 mph)
|Lowest pressure||1002 hPa (mbar); 29.59 inHg|
|Damage||$11.1 million (2018 USD)|
|Areas affected||Caroline Islands, Philippines, Central Vietnam|
|Part of the 2017 and 2018 Pacific typhoon seasons|
Tropical Storm Bolaven, known in the Philippines as Tropical Storm Agaton, was a weak tropical cyclone that affected southern Philippines in early January 2018. The system also spanned two calendar years, making it part of both the 2017 and 2018 seasons. The first named storm of the 2018 Pacific typhoon season, Bolaven formed as a tropical depression near Palau on December 29, 2017. The system moved westward and made landfall over Northeastern Mindanao on January 1, 2018. After traversing the Philippine islands, the system developed into a named tropical storm on January 3. However, Bolaven weakened back to a depression just a day later and dissipated soon after.
The third system to affect southern Philippines in as many weeks, Bolaven brought heavy rains and floods to areas that had already suffered severe effects from tropical storms Kai-tak and Tembin. Transport was greatly disrupted, with rough seas stranding over 2,000 people in various ports, and bus services cancelled due to floods. A total of three deaths were recorded to have occurred due to Bolaven.
Forming as part of the 2017 Pacific typhoon season, the Japan Meteorological Agency (JMA) began tracking on a weak tropical depression that had developed about 172 km (107 mi) to the south-southwest of Palau on December 31, 2017. By January 1, 2018, the PAGASA followed suit and gave the local name Agaton. On 12:00 UTC of the same day, the JMA started issuing advisories on the system, while the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert. Six hours later, the JTWC upgraded the system to a tropical depression and gave the designation of 01W.
Enhanced animated satellite imagery depicted a consolidating system with deep convection obscuring its low-level circulation center. Six hours later, the storm's center became partially exposed with some deep convection being sheared due to a slight increase in wind shear. By 18:00 UTC of January 2, the system was already located in an area of low to moderate shear as the storm emerged to the South China Sea. Despite the JTWC already predicting a weakening trend, the JMA finally upgraded the system to a tropical storm, naming it Bolaven, the first named storm of the season. Deep convection remained disorganized but persistent throughout the day as its LLCC became aforementioned. Despite satellite imagery depicted some flaring convection, the JMA issued its final advisory on Bolaven as it weakened back to a tropical depression early on January 4. The JTWC followed suit three hours later, after Bolaven's LLCC became fully exposed, with deteriorating convection. The JMA, however, continued tracking Bolaven's remnants until it fully dissipated on 06:00 UTC of the same day.
Preparations and impact
Agaton is the third of three consecutive storms that hugely impacted the lower half of the country after storms Kai-tak (Urduja) and Tembin (Vinta). On January 1, immediately after the PAGASA began issuing advisories, Public Storm Warning Signal #1 were put up in seventeen provinces, mostly in the Caraga region and Davao Region. Later, the island of Bohol was placed in a "high red alert" due to potential flooding, prompting 3 municipal local government units to order mandatory evacuation for residents. As the storm moved further west, Signal #1 was extended in lower provinces of Visayas, Zamboanga Peninsula and the island of Palawan, also mentioning that all areas placed under the signal would experience "moderate to heavy" rains within 24 hours. On January 2, sea vessels were barred from leaving Cebu province while Mahiga creek began to overflow. About 2,300 passengers were stranded in various ports while 34 sea vessels including 66 rolling cargoes were suspended. Negros Oriental also experienced canceled bus trips as the storm traversed the southern part of the country. Roughly 200 houses in Mandaue City were flooded. In Misamis Oriental, 23 families composing about 132 individuals were forced to evacuate due to flooding while some schools were announced suspended for January 3. Three people have been killed by the storm while total damages were recorded up to Php554.7 million (US$11.1 million).
- Tropical Depression Auring (2009)
- Tropical Storm Jangmi (2014)
- Cyclone Raquel – another cyclone that spanned two seasons.
- Typhoon Alice (1979) - a typhoon that also spanned two seasons.
- Jhoanna Ballaran (January 1, 2018). "Storm Signal No. 1 raised in several areas as LPA turns into depression". Inquirer.
- "RSMC Tropical Cyclone Adviosry TD". Japan Meteorological Agency. January 1, 2018.
- "Tropical Depression 01W (One) Warning Nr 001". Joint Typhoon Warning Center. January 1, 2018.
- "Prognostic Reasoning for Tropical Depression 01W (One) Warning Nr 01". Joint Typhoon Warning Center. January 1, 2018.
- "Prognostic Reasoning for Tropical Depression 01W (One) Warning Nr 02". Joint Typhoon Warning Center. January 2, 2018.
- "Prognostic Reasoning for Tropical Depression 01W (One) Warning Nr 05". Joint Typhoon Warning Center. January 2, 2018.
- "RSMC Tropical Cyclone Adviosry TS 1801 BOLAVEN (1801) UPGRADED FROM TD". Japan Meteorological Agency. January 3, 2018.
- "Prognostic Reasoning for Tropical Depression 01W (Bolaven) Warning Nr 07". Joint Typhoon Warning Center. January 3, 2018.
- "Prognostic Reasoning for Tropical Depression 01W (Bolaven) Warning Nr 09". Joint Typhoon Warning Center. January 3, 2018.
- "RSMC Tropical Cyclone Adviosry TD DOWNGRADED FROM TS 1801 BOLAVEN (1801)". Japan Meteorological Agency. January 4, 2018.
- "Tropical Depression 01W (Bolaven) Warning Nr 010". Joint Typhoon Warning Center. January 4, 2018.
- "LPA now Tropical Depression Agaton, Signal No. 1 up in 17 areas". GMA News. January 1, 2018.
- Michael O. Ligalig (January 1, 2018). "Bohol on high alert ahead of Tropical Depression Agaton". Rappler.
- "'Agaton' threatens Caraga; more areas under signal no. 1". ABS CBN. January 1, 2018.
- "Sea travel from Cebu banned as 'Agaton' lashes province". Inquirer. January 2, 2018.
- "More than 2,000 passengers stranded due to 'Agaton'". Sunstar Philippines. January 2, 2018.
- "Negros Oriental trips cancelled due to 'Agaton'". Sunstar Philippines. January 2, 2018.
- "'Agaton' leaves 200 houses in Mandaue City inundated". Sunstar Philippines. January 2, 2018.
- "SitRep No. 13 re Preparedness Measures and Effects of Tropical Depression "AGATON"" (PDF). January 22, 2018.
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