Typhoon Surigae, known in the Philippines as Super Typhoon Bising, was the strongest
Northern Hemispheretropical cyclone to form before the month of May, one of the
most intense tropical cyclones on record and the strongest tropical cyclone
worldwide in 2021.[1][2] The second named storm, first typhoon and first
super typhoon of the
2021 Pacific typhoon season, Surigae originated from a low-pressure area south of the
Micronesian island of
Woleai that organized into a tropical depression on April 12. At 18:00 UTC that day, it strengthened to a tropical storm and was named Surigae by the
Japan Meteorological Agency (JMA). The formation of an
eye and increasing winds prompted the JMA to upgrade the system to a severe tropical storm on April 13. The storm continued to gradually strengthen, and late on April 15, Surigae became a
typhoon. Very favorable environmental conditions then allowed Surigae to begin a bout of
rapid intensification; Surigae became a super typhoon the next day, and by April 17, the storm reached its peak intensity, with 10-minute sustained winds of 220 km/h (140 mph),[nb 1] 1-minute sustained winds of 315 km/h (196 mph), and a minimum pressure of 895 hPa (26.4 inHg). This made it the strongest pre-May typhoon on record. Afterward, the storm's weakening outflow and an
eyewall replacement cycle caused Surigae to gradually weaken as its track shifted north-northwestward in the
Philippine Sea. Following the eyewall replacement cycle, Surigae became an
annular tropical cyclone on April 19, and restrengthened slightly. On April 22, the storm began to rapidly weaken as it accelerated northwestward into unfavorable environmental conditions, transitioning into a
subtropical storm the next day. The subtropical system subsequently underwent
extratropical transition, which it completed by April 24. Afterward, Surigae's extratropical remnant accelerated northeastward. On April 27, Surigae's remnant explosively intensified into a
bomb cyclone near the
Aleutian Islands, attaining hurricane-force winds. Afterward, the system gradually weakened as it turned eastward, slowing down in the process, before crossing the
International Date Line on April 30 and fully dissipating on May 2.
Upon Surigae's naming,
watches and warnings were issued for the island of
Yap in the
Federated States of Micronesia and the islands of
Koror and
Kayangel in
Palau as well. The typhoon left US$4.8 million in damage in Palau after cutting off power, water, and destroying infrastructure.[nb 2] Later, warnings were raised for parts of the
Philippines as the typhoon moved closer to the nation, with evacuations taking place in eastern regions of the
Visayas. The storm killed at least 10 people and left another eight missing, in addition to causing at least
₱272.8 million (
US$5.67 million) in damage in the Philippines.
A strong
rainband along the depression's northern semicircle became prominent and coalesced around a robust and developing
central dense overcast.[11] At 18:00
UTC on the same day, the JMA upgraded the system to a
tropical storm and
named it Surigae.[12][13] Surigae was also upgraded to a tropical storm by the JTWC in the early hours of April 14, as the system progressed westward in the
Philippine Sea.[14][15] The storm continued to move slowly, remaining nearly stationary on April 14 – as it gradually intensified.[16][17] Surigae's convective activity was initially displaced to the west of its center of circulation, though additional rainbands and thunderstorm development later covered the central vortex.[18][19] On April 15, the JMA upgraded Surigae to a severe tropical storm as it moved closer to the island nation of
Palau.[20] A formative
eye became apparent on
microwave satellite imagery later that day.[21]
By April 16, Surigae strengthened to a typhoon just north of Palau, making it the first typhoon of the 2021 Pacific typhoon season.[22][23] The typhoon's convective activity had become tightly wound around its center, indicating additional strengthening.[24] On April 16 at 03:00 UTC, the
Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) gave the storm the local name Bising as it entered the
Philippine Area of Responsibility.[25] The system's eye became apparent through the central overcast, preceding a period of
rapid intensification as Surigae progressed west-northwestward through a conducive environment.[26][27][28] Surigae's central dense overcast became colder and better-organized, with a well-defined ring of very cold
cloud tops encircling a 26 km (16 mi) diameter eye.[29] Concurrently, an approaching
trough produced a gap in the subtropical ridge of high pressure to the north, causing Surigae to slowly curve northwest as it quickly strengthened.[30]
On April 17, the JMA determined that Surigae's
barometric pressure had rapidly fallen to 895
hPa (
mbar; 26.43
inHg), as the storm reached its peak intensity.[31][32] Its 10-minute
maximum sustained winds reached 220 km/h (135 mph) according to the JMA, while one-minute maximum sustained winds reached 315 km/h (195 mph) according to the JTWC, making it equivalent to a Category 5 super typhoon on the
Saffir–Simpson scale (SSHWS);[nb 5][34][35] the peak 1-minute sustained winds were also higher for the time of year than any previous typhoon on record.[31] The JTWC also estimated a minimum central pressure of 882 hPa (mbar; 26.05 inHg) for Surigae at the time.[36] Later that day, Surigae began an
eyewall replacement cycle causing its eye to become less apparent on satellite imagery and its winds to slightly diminish. The trough to Surigae's north also impeded the typhoon's outflow, resulting in a decrease in environmental favorability for further intensification.[37][38] On April 18, Surigae finished its eyewall replacement cycle;[38] Surigae acquired
annular characteristics, bearing a symmetrical appearance and a large eye, which was largely surrounded by one large
rainband, by the next day.[36]
By April 20, the prevalence of nearby dry air and
upwelling of cold waters beneath the slow-moving typhoon caused its winds to decrease further.[39][40] Some reorganization occurred when Surigae began to move north and away from the upwelled waters, with its large eye becoming less ragged;[39] however, additional entrainment of dry air originating from the mid-troposphere over
Luzon caused Surigae's structure to degrade further on April 21.[41] Surigae turned northeast away from the
Philippines later that day and weakened further, upon entering an environment with strong westerly winds in the upper troposphere.[42][43] The once large and clear eye disappeared on April 22, leaving behind an increasingly-disheveled cluster of weakening showers and thunderstorms.[44] Soon afterward, all of Surigae's remaining convection was sheared to the east, as the storm moved over cooler waters.[45] As most of the remaining thunderstorms had dissipated, Surigae transitioned into a
subtropical cyclone on April 23 due to interacting with an upper-level atmospheric
trough as Surigae traversed a cold oceanic
eddy.[46] Surigae began to undergo
extratropical transition, a process it completed late on April 24, at which time the JTWC issued their final advisory on the system.[47] The JMA declared that Surigae had become extratropical a few hours later.[48]
As an extratropical cyclone, Surigae underwent
explosive cyclogenesis on April 26, with its central pressure falling 44 hPa (mbar; 1.3 inHg) within 24 hours, while rapidly tracking northeastward.[49] While located to the east of
Hokkaido, the system's ten-minute maximum sustained winds reached 130 km/h (80 mph) at 18:00 UTC that day,[50] and its central pressure bottomed out at 944 hPa (mbar; 27.88 inHg) six hours later.[51] Late on April 27, Surigae's remnant started to weaken while turning eastward. The next day, the system's forward motion significantly slowed down. On April 30, Surigae underwent a center reformation, with the original center of low pressure dissipating, and a new low-pressure center forming shortly afterward, which quickly dominated the system.[52] Afterward, Surigae's remnant continued moving eastward while gradually weakening, turning northeastward on May 1. On May 2, Surigae's remnant was absorbed into another extratropical cyclone, just south of the
Alaskan Panhandle.
Preparations
Due to the threat of the storm, a
Tropical Storm Watch was issued for the island of
Yap and
Ngulu Atoll as well as for
Koror and
Kayangel in Palau on April 14,[53] where in the former, winds exceeded 30 mph (48 km/h).[54] The watch was upgraded to a Tropical Storm Warning for Ngulu Atoll later that day.[55]
As Surigae entered the Philippine Area of Responsibility, the PAGASA began issuing weather bulletins for the nearby storm. Initial forecasts by the agency suggested that the storm was less likely to make landfall over
Luzon, and expected the storm to re-curve away from the Philippines.[25][56][57] On April 16, the
Department of Transportation of the Philippines suspended all air and land travel to and from
Visayas and
Mindanao.[58] In the ensuing travel suspension, 2,507 individuals and 61 sea vessels were stranded in ports throughout the country.[59] Wave heights as high as 4.5 m (15 ft) were forecast near the eastern coasts of Visayas and Mindanao.[60] In order to avoid agricultural losses, Secretary
William Dar of the
Department of Agriculture encouraged farmers in the
Bicol and
Eastern Visayas regions to harvest their crops and for fishermen to refrain from fishing due to worsening oceanic conditions.[57][61] At 15:00 UTC (23:00 PHT), the PAGASA began issuing
Tropical Cyclone Wind Signal (TCWS) #1 for areas in Eastern Visayas and the
Caraga Region, as well as for portions of Luzon six hours later.[62][63]
On April 17, TCWS #2 was issued for
Catanduanes and the entire island of
Samar.[64] Flood advisories were also issued by the PAGASA for three regions in Visayas and Mindanao.[65] In preparation for the intense rains, the
National Telecommunications Commission ordered telecommunications companies to prepare facilities in forecasted affected areas, including free calling and charging stations.[66][67][68] As early as April 17, preemptive evacuation began in the Bicol Region and the
Samar province,[69] and by April 21, 169,072 people were evacuated in the
Cagayan Valley,
Bicol Region,
Eastern Visayas, and
Caraga. Flights in
Daniel Z. Romualdez Airport and all Tacloban Airports were cancelled on April 18, and other domestic flights were also cancelled on the same day.[67] In addition, 10 domestic flights elsewhere were also cancelled that day.[59] Schools and work activities were suspended in the Bicol Region till April 20.[70]₱1.5 billion (
US$31.05 million) worth of standby funds were prepared for disaster response.[71]
Impact
Micronesia and Palau
Locally heavy rainfall occurred in parts of
Palau and Yap for several days.[72] Surigae brought sustained winds of up to 80 km/h (50 mph) and gusts up to 135 km/h (84 mph) to Palau, causing power outages across the island.[73][74][75] Large swells from the developing storm brought
coastal flooding to
Koror and Yap. Residents in those areas were advised to avoid reef lines in the north and west, and to take caution on beaches due to
rip currents and large waves.[76] Surigae was the closest typhoon to pass near the island of Palau since
Typhoon Haiyan.[77] Restaurants, sporting events and other services were closed in Palau as Surigae approached closer– yet schools remained open.[77] Schools were not suspended until power had been cut off across much of the entire country.[77] Water and cellular services were also downed.[77] There was criticism for the lack of news coverage on the typhoon in Palau most notably.[77] 125 homes across the country were destroyed, while at least 1,500 sustained minor damage.[75] The entire population of Palau, consisting of approximately 18,008 people, was impacted by the typhoon.[75] At least US$2 million worth of infrastructure alone was damaged in Palau.[78] The total amount of damage across health, infrastructure, education, food, communication, utilities and other sectors was assessed at US$4.8 million.[75] President of Palau
Surangel Whipps Jr. issued a
national state of emergency on April 18.[79] The
United States Agency for International Development (USAID) provided US$100,000 for immediate assistance to support those affected.[80] In
Guam, emergency supplies were being prepared and donated to communities in need in Palau.[79]
Philippines
Five people in a boat were rescued off the coast of
Pujada Bay due to dangerous sea conditions produced by Surigae.[81] Another boat with two fishermen aboard capsized during midnight on its way to
Bantayan Island, with both of two fishermen having to swim back to shore.[82] On April 19, Surigae forced the cargo ship LCU Cebu Great Ocean, carrying twenty crew members and
nickelore, to run aground on the coast of the Province of
Surigao del Norte, in the southern Philippines.[83][84] At least six of the crew members were found dead, while seven were rescued; the search continues for another missing seven crew members.[85][86] Heavy rain from the outer bands of Surigae battered Eastern Visayas and the Bicol Region as it passed around 345 km (214 mi) to the east of Catanduanes.[87] Widespread rainfall totals of up to 8–12 inches (200–300 mm) occurred in the eastern Philippines, while 20.13 inches (511 mm) of rain fell in
Virac, Catanduanes and surrounding areas.[88] A
funnel cloud was also briefly reported in
Camarines Sur.[89] Twenty-two
barangays were flooded in Eastern Visayas, and in the municipality of
Jipapad, flooding reached 4 metres (13 ft). Power interruptions were experienced in
Central Visayas, Eastern Visayas and in
Eastern Samar, power was interrupted for the whole province.[67] 109,815 people were displaced by flooding and landslides in the Bicol Region.[90]
Ten deaths were reported due to the typhoon. One person in
Southern Leyte and another in
Cebu died due to fallen coconut trees.[91][92] Six crew members of the LCU Cebu Great Ocean were found dead after the ship ran aground in the southern Philippines; another seven crew members remain missing.[85][86] Another person remains missing in Northern Samar.[93] 13 others were injured.[91] A total of 3,385 houses were damaged in the Bicol Region, Eastern Visayas and Caraga, with 158 totally destroyed. Agricultural damage in the Bicol Region and Eastern Visayas reached
₱261.9 million (
US$5.43 million), while infrastructural damage totaled ₱10.87 million (US$226,000).[94] 63 cities experienced power interruptions; however, power was restored in 54 of those cities.[95]
The influence of Surigae caused gusts in
North Sulawesi that reached 23 mph (37 km/h).[97] Large waves of 13.1–19.8 feet (4.0–6.0 m) affected the coastal waters of the
Sitaro Islands Regency,
Sangihe Islands Regency, the
Talaud Islands and the northern
Molucca Sea.[98]
Surigae made its closest approach to Taiwan on April 22. The typhoon's outer bands brought much-needed rainfall to central Taiwan, which was going through its worst drought in 56 years. There were also reports of hail.[99] Large waves up to 4.2 m (14 ft) tall generated by Surigae were recorded along Taiwan's east coast on April 21.[100]
^The Joint Typhoon Warning Center is a joint
United States Navy –
United States Air Force task force that issues tropical cyclone warnings for the western Pacific Ocean and other regions.[9]
^A super typhoon is an unofficial category used by the
Joint Typhoon Warning Center (JTWC) for a typhoon with winds of at least 240 km/h (150 mph).[33]
^Significant Tropical Weather Advisory for the Western and South Pacific Oceans Reissued 101330Z-110600Z April 2021 (Report). Pearl Harbor, Hawaii: Joint Typhoon Warning Center. April 10, 2021.
^Significant Tropical Weather Advisory for the Western and South Pacific Oceans Reissued 111430Z-120600Z April 2021 (Report). Pearl Harbor, Hawaii: Joint Typhoon Warning Center. April 11, 2021.
^Warning and Summary 120600 (Report). Tokyo, Japan: Japan Meteorological Agency. April 12, 2021.
Archived from the original on April 14, 2021. Retrieved April 14, 2021 – via Iowa Environmental Mesonet.
^"Tropical Cyclone Advisory #1"(PDF). Manila, Philippines: Philippine Atmospheric, Geophysical and Astronomical Services Administration. April 12, 2021. Archived from
the original(PDF) on April 13, 2021. Retrieved April 13, 2021.
^TS 2102 Surigae (2102) Advisory 140600 (RSMC Tropical Cyclone Advisory). Tokyo, Japan: Japan Meteorological Agency. April 14, 2021. Archived from
the original(TXT) on April 15, 2021. Retrieved April 15, 2021.
^TS 2102 Surigae (2102) Advisory 142100 (RSMC Tropical Cyclone Advisory). Tokyo, Japan: Japan Meteorological Agency. April 14, 2021. Archived from
the original(TXT) on April 15, 2021. Retrieved April 15, 2021.
^Frequently Asked Questions (Report). Joint Typhoon Warning Center. August 13, 2012.
Archived from the original on October 4, 2013. Retrieved September 22, 2012.
^Llemit, Ralph Lawrence G. (April 18, 2021).
"5 rescued from sinking boat". Sunstar.
Archived from the original on April 19, 2021. Retrieved April 18, 2021.