The 2001 Pacific typhoon season was an slightly above-average season with twenty-six named storms, sixteen typhoons and three super typhoons. It ran year-round in 2001, with most tropical cyclones in the northwestern Pacific Ocean tending between May and November.
The early season was relatively inactive, with the first named storm, Cimaron, not developing until May 9. Taiwan suffered the most destruction from typhoons this year, with Typhoons Toraji, Nari, and Lekima being responsible for nearly 300 deaths in that island alone, making it one of the deadliest typhoon seasons in recorded history in that island. In November, Typhoon Lingling impacted the Philippines, killing 171 people, making it one of the deadliest Philippine storms this century. The season ended with the formation of Tropical Storm Vamei during the last week of December. Vamei would be notable for becoming the lowest latitude tropical storm, at 1.4°N, ever to be observed in the Northwest Pacific.
The scope of this article is limited to the Pacific Ocean, north of the equator and west of the International Date Line. Storms that form east of the date line and north of the equator are called hurricanes; see 2001 Pacific hurricane season. Tropical storms that formed in the West Pacific basin are assigned a name by the Tokyo Typhoon Center. Tropical depressions in this basin have the "W" suffix added to their number. Tropical depressions that enter or form in the Philippine area of responsibility are assigned a name by the Philippine Atmospheric, Geophysical and Astronomical Services Administration or PAGASA. This often results in the same storm having two names.
Seasonal forecasts TSR forecastsDate Tropicalstorms TotalTyphoons IntenseTCs Ref Average (1971–2000) 27.2 17.0 8.2 January 31, 2001 28.1 16.2 6.6 June 15, 2001 26.1 17.5 8.7 2001 season ForecastCenter Tropicalcyclones Tropicalstorms Typhoons Actual activity: JMA 43 25 16 Actual activity: JTWC 33 30 20 Actual activity: PAGASA 17 12 6 During the year, the Japan Meteorological Agency (JMA) issued advisories on tropical cyclones west of the International Date Line to the Malay Peninsula, and north of the equator, in its role as the official Regional Specialized Meteorological Center, as designated by the World Meteorological Organization in 1989. The JMA issued forecasts and analyses every six hours starting at midnight UTC using numerical weather prediction (NWP) and a climatological tropical cyclone forecast model. They used the Dvorak technique and NWP to estimate 10-minute sustained winds and barometric pressure. The JTWC also issued warnings on storms within the basin, operating from Pearl Harbor in Hawaii and supplying forecasts to the United States Armed Forces in the Indian and Pacific Oceans.
On January 31, Tropical Storm Risk (TSR) issued their extended range forecast for the Northwest Pacific in 2001, predicting near-average activity in terms of tropical storms, but a slightly below average in terms of typhoons. They predict that around 28 tropical storms would form, in which 17 of them would become typhoons, and 8 would further intensify to intense typhoons. TSR uses anomalous patterns of sea-surface temperatures (SSTs) over in the Niño 3.4 region (5°N-5°S, 120°W-170°W) during the August–September SST forecast as a predictor. With a predicted anomaly of −0.27 °C, a weak La Niña is expected — which tends to suppress tropical cyclone activity or intensity. On June 15, TSR issued their pre-season forecast, predicting a neutral typhoon season. Predicted tropical storm numbers have decreased to 26, but both their predicted typhoon and intense typhoon numbers have increased to 18 and 9, respectively. The key factor to this prediction is now due to the anticipated neutral value for the August–September SST forecast in the Niño 4 region (5°S – 5°N, 150°W – 160°E) of +0.27 °C.
Seasonal summary
The Accumulated Cyclone Energy (ACE) index for the 2001 Pacific typhoon season as calculated by Colorado State University using data from the Joint Typhoon Warning Center was 307.3 units. Broadly speaking, ACE is a measure of the power of a tropical or subtropical storm multiplied by the length of time it existed. It is only calculated for full advisories on specific tropical and subtropical systems reaching or exceeding wind speeds of .
The season ran with weak La Niña conditions during the first quarter of the year and near-normal conditions throughout the rest of the year, with average sea-surface temperatures in the Niño 3.4 region of around −0.3 °C. It was the final year of a rather strong La Niña episode that persisted throughout most of the Pacific Ocean since 1998. This was demonstrated with this season's tropical activity being more active than the previous three seasons, but overall tropical activity still remaining below average.
2001 opened with Tropical Storm Soulik, from the previous season, active in the Philippine Sea. Soulik strengthened into the first typhoon seen this year and reached its peak intensity as a Category 3-equivalent typhoon on January 3, before quickly dissipating the next day. The formation of Tropical Depression 01W (Auring), however, officially initiated the start of the annual typhoon season on February 17. No tropical cyclones developed until after two months later, when another tropical depression had developed to the southeast of the Philippines. Tropical cyclogenesis gradually increased when May arrived – with three tropical systems developing. Two of these systems were only recognised as minor tropical depressions, while the other strengthened to the first official named storm of this year, Cimaron, which moved through the Philippine archipelago in the middle of the month.
Systems Tropical Depression 01W (Auring)
On 18:00 UTC of February 17, both the JMA and PAGASA began to track a tropical depression that was located about to the northeast of Surigao of Northern Mindanao. The PAGASA named the system, Auring. The JTWC followed suit and designated it 01W, six hours later. Auring moved westward and began traversing the Philippine archipelago of Visayas. By February 19, the PAGASA issued its final warning on Auring. The JTWC also issued its final advisory on the system on February 20. The JMA downgraded the system to a low-pressure area, and its remnants tracked northward, where it was last noted off the coast of the Ilocos Region on February 23.
Auring brought rainfall throughout most of Visayas and Mindanao. At least 18 people died, with most of these deaths due to landslides that occurred from the torrential rain. In Leyte and most of Mindanao, flooding submerged the homes of 159,785 people. Damages from crops and property have been estimated at ₱200 million (US$4.16 million).
Tropical Depression 02W (Barok)
The PAGASA began issuing advisories on Tropical Depression Barok on 06:00 UTC of April 16, located to the west of Palau. Six hours later, the JTWC followed suit on initiating advisories, where they designated it as 02W. Barok moved in a northwestward direction well to the east of the Philippines without any intensification. By April 19, both agencies stopped warning on the system when the depression quickly deteriorated. Even though warnings were discontinued, its remnants continued to show signs of life with several bursts of convection. This prompted the JTWC to issue a Tropical Cyclone Formation Alert (TCFA) on April 21, however its convection significantly weakened.
Severe Tropical Storm Cimaron (Crising)
A weak low-level circulation center (LLCC) south of Koror developed from a monsoon trough on May 4. The system was later upgraded to a tropical depression and was assigned 03W by the JTWC on May 7, before the JMA followed suit in upgrading its status on May 9, and at the same time, was assigned the name Crising by PAGASA after it entered its responsibility area. The following day, Tropical Depression 03W intensified to a tropical storm and was given the name Cimaron by the JMA. The storm was weakened by vertical wind shear on May 12, before it resumed intensifying and by May 13, was upgraded to a severe tropical storm after attaining 10-minute sustained winds of . Cimaron slowly began to transition into an extratropical cyclone due to a weakening trend with vertical shear as the storm accelerated northeastward. Cimaron passed over southwest of Naha, Okinawa on May 14, before transitioning into an extratropical cyclone and becoming last noted by the JMA on May 15.
After having become an extratropical cyclone, strong winds struck the Ishigaki Island on May 14 and caused a building to collapse and also damage a plastic greenhouse. The damages in the island were estimated at million (US$ thousand) Furthermore, at Miyako Island, an additional million (US$ million) of damages occurred, and 22 flights were cancelled for 14 days. The storm later approached Okinawa, and around 20,000 people were affected, due to roads being flooded, and land transportation was crowded. A landslide out of three occurred in Naha City, resulting in 19 people evacuating and a household losing power. The overall damages in Okinawa totaled million (US$ million).
Typhoon Chebi (Emong)
On June 19, an area of convection developed southeast of Yap and by 18:00 UTC, was centered east-northeast of Palau. Rapid development occurred and the disturbance became identified as Tropical Depression 04W by the JTWC at 21:00 UTC. After entering the PAR and receiving the name Emong by PAGASA, the depression intensified into a tropical storm on June 20. Chebi headed northwest while being located east of the Philippines on June 21 at 06:00 UTC, and would later attain severe tropical storm intensity, before intensifying further to a typhoon the following day. Chebi reached its peak intensity on June 23, before a trough forced Chebi west and northwest where it made landfall near Fuzhou City, China. Chebi rapidly weakened while accelerating northward, and would degrade into an extratropical cyclone on June 24. Its remnants were last noted by the JMA along with other weather centers before dissipating on June 30.
Chebi killed 82 people, mostly in China, and left $422 million (2001 USD), $457 million (2005 USD). Chebi's heavy rains and strong winds left nine people dead, 28 missing and $13 million (2001 USD) in damage in the Philippines. Four of the nine were from a Belizean freighter that sank during the storm.http://72.14.207.104/search?q=cache:B1Z3B7KbI6kJ:www.japantoday.com/gidx/news37918.html+Typhoon+Chebi+,+Taiwan&hl=en&gl=us&ct=clnk&cd=4 The Penghu Islands, which took the brunt of the typhoon, suffered considerable damage as 102 fishing boats sank and ten thousand people were left without power. The storm also crippled ground and air traffic. A rain laden typhoon, Chebi produced 100 millimeters of rain across Guangdong. About 73 people were killed in China, most of them in the southeastern province of Fujian.http://72.14.207.104/search?q=cache:9R6lRuW8kScJ:www.japantoday.com/gidx/news37987.html+Typhoon+Chebi+,+Taiwan&hl=en&gl=us&ct=clnk&cd=3 The storm also destroyed several thousand acres of crops, resulting in economic losses. In Ningde, about 321,400 houses were destroyed by the typhoon. About 22 people were killed in Hangzhou when a landslide burst through a construction wall.
Severe Tropical Storm Durian