Hurricane Otto (2010)

Hurricane Otto
Category 1 hurricane (SSHWS/NWS)

Hurricane Otto as a Category 1 storm
Formed October 6, 2010
Dissipated October 18, 2010
(Extratropical on October 10)[1]
Highest winds 1-minute sustained: 85 mph (140 km/h)
Lowest pressure 976 mbar (hPa); 28.82 inHg
Fatalities None reported
Damage $22 million (2010 USD)
(Preliminary estimate)
Areas affected Leeward Islands, Virgin Islands, Puerto Rico
Part of the 2010 Atlantic hurricane season

Hurricane Otto was a moderate Category 1 storm that caused widespread damage in portions of the northeastern Caribbean islands in October 2010. Otto originated as a subtropical cyclone north of Puerto Rico on October 6, and transitioned into a tropical storm the next day, the fifteenth of the season. Steadily tracking northeastward, Otto strengthened into a Category 1 hurricane on the Saffir–Simpson scale on October 8, with winds peaking at 85 mph (140 km/h). The storm subsequently entered a weakening trend due to incompatible surroundings, and became extratropical west of the Azores on October 10. Additionally, Otto was the first Atlantic tropical cyclone on record to have transitioned from a subtropical storm since Tropical Storm Laura in 2008.[2]

The storm dropped heavy rainfall in the northern Leeward Islands, the Virgin Islands, and Puerto Rico for several days, triggering widespread flooding and several mudslides. Subsequently re-curving toward the northeast, Otto proceeded across the open Atlantic, and no further landmasses were affected. Overall, damage estimates as a result of the storm have amounted to over $22 million (2010 USD).

Meteorological history

Storm path

In late September, a large area of disturbed weather associated with two tropical waves formed just to the east of the Lesser Antilles.[3] The disturbance drifted generally west-northwestward,[4] and strong wind shear eventually caused the westernmost wave to dissipate.[5] Albeit weak, the remaining surface trough persisted and stalled in the extreme eastern Caribbean Sea for several days as a nearby upper-level low retrograded to its north.[5][6] By October 5, the trough drifted northward into a more favorable environment over the Virgin Islands, allowing a surface low to form. The low became well-defined and produced a large band of cloudiness and thunderstorms over the northeastern Caribbean.[7] Surface pressures in association with the low began to drop over the next day, and it acquired a more prominent subtropical structure:[8][9] the storm sustained a notably larger maximum wind radius than those of purely tropical cyclones. Additional observations also revealed an entanglement of the mean low and the upper-level low near its southwestern periphery, confirming the hybrid nature of the system.[10] It was therefore designated Subtropical Depression Seventeen on October 6, located 265 mi (425 km) to the north-northwest of San Juan, Puerto Rico.[1]

The depression slowly proceeded northwestward, between the contiguous upper low and a large ridge over the central Atlantic Ocean. An area of lighter wind shear lying ahead, as well as an anticipated weakening of the upper low, led the NHC to introduce the possibility of tropical cyclogenesis.[10] Subsequent satellite observation showed a significant increase in organization; convective banding cumulatively wrapped around the broad inner-core wind field, and winds gusted to 65 mph (110 km/h).[11] Moments later, the formation of Subtropical Storm Otto was issued about 215 mi (345 km) northeast of Grand Turk.[12] Although satellite imagery continued to display a classical subtropical cyclone, with the storm surface and the upper low nearly collocated, data obtained during a Hurricane Hunters flight revealed a weak warm core strengthening within the mid levels of the circulation—a feature present at the upper levels of tropical cyclones. As well, a contraction of the large wind field reaffirmed that Otto was entering the final stages of its tropical transition.[13] Struggling to produce much convection, the storm briefly weakened overnight, though weakening shear and considerably warmer sea surface temperatures permitted a small amount of convection to reignite on the morning of October 7.[14] Several hours later, temperatures associated with forecast models indicated that the warm core within the circulation had ascended to the upper levels of the cyclone. As a result, a burst of deep convection with extreme cloud top temperatures of approximately −112° F (−80° C) occurred over the center.[15] Having shed the last of its subtropical characteristics, Otto became a warm-core system and was operationally declared tropical at 1200 UTC.[1]

Hurricane Otto weakening over the Atlantic

Later that day, Otto came under the increasing influence of a large deep-layer trough off the US East Coast.[16] As conditions aloft remained conducive, convection symmetrically deepened near the center of circulation early on October 8.[17] Steadily increasing in organization, Otto gradually developed a large, well-defined central dense overcast; furthermore, there were indications of the formation of a mid-level eyewall. Based on these features, the storm was upgraded to a Category 1 hurricane south of Bermuda, with winds set at 75 mph (120 km/h).[18]

With little vertical wind shear aloft, further intensification ensued as the newly formed hurricane continued to track over favorable sea surface temperatures. At 0300 UTC October 9, microwave imagery showed the indistinct eyewall was open at all levels, signifying a reach of peak strength of winds estimated at 85 mph (140 km/h).[19] Upon peaking in intensity, Otto had become fully embedded within the deep-layered flow to its southwest.[19] Speeding toward the northeast, the storm entered an area of progressively cooler waters as upper-level conditions quickly turned adverse. In response, storm cloud patterns gradually decreased in organization and convective cloud tops warmed significantly;[20][21] central convection became fairly disheveled, causing the storm to come unraveled rapidly. Otto was reduced to a tropical storm shortly thereafter, sustaining maximum winds of less than 70 mph (110 km/h).[22] Convection further diminished due to intensified shear conditions and a perpetual lack of tropical moisture, leading specialists to conclude the storm was entering an extratropical transition.[23] In addition, cool, dry air slowly began wrapping around the inner-core of the cyclone; within hours, the system barely retained its weak warm core and eventually developed frontal cloud bands.[24] With this, Otto was confirmed post-tropical as of October 10, and the NHC discontinued advisories on the storm.[25] The remnant extratropical cyclone decelerated near the Azores, where it eventually degenerated into a remnant low and completely dissipated to the west of Morocco, early on October 18.[1]

Preparations and impact

Otto shortly after completing tropical cyclogenesis

Otto and its precursor disturbance produced days of prolonged rainfall and gusty winds across the northern Leeward Islands, the Virgin Islands, and Puerto Rico. Localized flooding and rough sea conditions caused extensive road damage, infrastructure failures, and some beach erosion along coastlines. During the passage of the storm, numerous residents were left without water and power, and a state of emergency was declared for several Caribbean nations. Schools, businesses and some government offices across all of the Virgin Islands and Saint Kitts and Nevis were closed until storm conditions abated.[26][27] The weather system ultimately accounted for substantial monetary losses throughout these areas, pinned at over $22 million (2010 USD). In addition, Otto was widely regarded to be one of the wettest storms in recent local history, repeatedly shattering various precipitation records.[28][29]

Leeward Islands

In Saint Lucia, downpours triggered torrential flooding along the island's easternmost coast from October 5 through October 6.[30] In Dennery Quarter, flash floods affected about 500 households; among them, 400 had their houses flooded or severely damaged. Several residences had to be evacuated, and some people were trapped in their homes.[31] Residents also suffered from the absence of drinking water, lack of electricity, and the inability to prepare meals due to the loss of kitchen equipment and other utensils.[32] In response, the area was declared a disaster zone;[26] a total of EC$500,000 ($185,185 USD) was approved to assist flood victims, as well as an additional US$44,194 allocated from the Disaster Relief Emergency Fund of the International Federation of Red Cross and Red Crescent Societies.[32]

Intermittent torrents battered Saint Kitts and Nevis for at least four days; a total of up to 10.99 inches (279 mm) of precipitation was recorded during that time. Several homeowners reported significant flooding, and a number of persons had to be rescued from their homes. Gusty winds generated rough sea conditions along coastal regions, resulting in some beach erosion and the collapse of a sidewalk section. Rains and associated floods topped a number of culverts and bridges, washed out the sides of some roadways, and damage to some utility lines, followed by significant disruptions to electricity services.[33] The exact amount of damage to the territory remains unknown, however.

In the U.S. Virgin Islands, heavy rainfall resulted in flooding of some local roads. Due to the flooding, officials opened shelters on all three islands on October 6.[34] In Saint Croix, a roadway section leading into Enfield Green collapsed during the night, temporarily cutting the south-side neighborhood off to vehicle traffic until a makeshift roadway was created the next day. On the island's North Shore in La Vallée, flooding and landslides created some issues for low-lying areas.[34] Initially, the roads remained passable; however, as rain continued throughout the next day, floods, mudslides, and asphalt erosion in Saint Thomas and Saint John prompted authorities to issue the closure of several roads.[35] Rainfall associated with Otto shattered numerous records across the US Virgin Islands, with a maximum total of 21.52 in (547 mm) reported in Red Hook, Saint Tomas.[29] Preliminary damage estimates were placed at $2 million.[36]

In the British Virgin Islands, a flash flood warning was in effect during the presence of Otto from October 6 to 8.[37][38] Torrential floods across the islands overturned several cars, and caused extensive damage to utility lines and drainage pipes; dozens of people in Tortola—specifically in Road Town—were temporarily left without power and water.[39] In total, an estimated 24.98 inches (634 mm) of rain was recorded, and the government declared a state of emergency for the entire territory.[40]

Subtropical Depression Seventeen to the north of Puerto Rico.

Throughout the British Virgin Islands, floods following the storm were regarded as the worst in the history of the islands.[28][41] In total, damage across the islands was preliminarily estimated at US$10.5 million, considerably higher than losses ensured by Hurricane Earl earlier in the year.[42] Additionally, Otto was held responsible for substantial increases in damage to road network across Sint Maartin initially induced by Earl, amounting to over NAƒ1.5 million ($837,988 USD).[43] On the other side of the island, torrents and associated floods were accountable for similar damages; monetary losses in Saint Martin were estimated at €800,000 ($1.12 million USD).[44]

Puerto Rico

Storm total rainfall related to Otto in Puerto Rico

Rain began to pour across several parts of Puerto Rico on October 5, persisting for up to five days in some areas. The greatest amount of rainfall during the six-day period of October 3 to 8 was registered at Rio Portugues in Ponce, with 17.86 inches (454 mm) recorded.[45] Due to the rainfall, the Government of Puerto Rico issued the closure of more than 40 roads, and an additional 19 streets were partially secured.[46] Subsequent widespread flooding affected at least 295 roads, 14 of which suffered significant damage. In all, damage to road infrastructure was preliminarily estimated at US$6.5 million.[47] In addition, the municipality of Ponce reported copious losses in agriculture, later estimated at US$1.5 million.[48]

Following the overflow of the Arecibo River on October 7, a neighborhood in Utuado was cut off from surrounding communities after gushing waters severely damaged its main road. Shortly thereafter, a landslide lugged a utility pole along the road, making it impossible for larger vehicles—including ambulances—to access the site. Landslides trapped fourteen families in the municipality of Ponce; a residence alongside a road suffered significant damage and had to be evacuated. In Cayey, a district was isolated from neighboring areas due to the collapse of a bridge. In the area, burst riverbanks triggered floods across local streets, which trapped dozens of families in their homes.[49] Severe flooding contaminated water supplies, leaving an estimated 45,000 people without drinking water in the wake of the storm. In response, the government declared a state of emergency for the entire island. Authorities opened 120 shelters, and several flood victims had to be rescued.[50]

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 John Cangialosi (2010). "Hurricane OTTO Tropical Cyclone Report" (PDF). National Hurricane Center. Retrieved 2010-11-19.
  2. ↑ National Hurricane Center; Hurricane Research Division (March 2, 2015). "Atlantic hurricane best track (HURDAT version 2)". United States National Oceanic and Atmospheric Administration. Retrieved April 25, 2015.
  3. ↑ Richard Pasch (2010). "Graphical Tropical Weather Outlook". National Hurricane Center. Retrieved 2010-09-30.
  4. ↑ Michael Brennan (2010). "Graphical Tropical Weather Outlook". National Hurricane Center. Retrieved 2010-10-01.
  5. ↑ 5.0 5.1 Hydrometeorological Prediction Center of the NCEP (2010). "Hurricane Otto".
  6. ↑ Stacy Stewart (2010). "Graphical Tropical Weather Outlook". National Hurricane Center. Retrieved 2010-10-05.
  7. ↑ Stacy Stewart (2010). "Graphical Tropical Weather Outlook". National Hurricane Center. Retrieved 2010-10-05.
  8. ↑ Robbie Berg (2010). "Graphical Tropical Weather Outlook". National Hurricane Center. Retrieved 2010-10-05.
  9. ↑ Robbie Berg (2010). "Graphical Tropical Weather Outlook". National Hurricane Center. Retrieved 2010-10-06.
  10. ↑ 10.0 10.1 Eric Blake (2010). "Subtropical Depression Seventeen Discussion 1". National Hurricane Center. Retrieved 2010-10-06.
  11. ↑ Stacy Stewart (2010). "Subtropical Storm Otto Discussion 3". National Hurricane Center. Retrieved 2010-10-06.
  12. ↑ Stacy Stewart (2010). "Subtropical Storm Otto Advisory 3". National Hurricane Center. Retrieved 2010-10-06.
  13. ↑ Robbie Berg (2010). "Subtropical Storm Otto Discussion 4". National Hurricane Center. Retrieved 2010-10-06.
  14. ↑ Eric Blake (2010). "Subtropical Storm Otto Discussion 5". National Hurricane Center. Retrieved 2010-10-07.
  15. ↑ Stacy Stewart (2010). "Tropical Storm Otto Discussion 6". National Hurricane Center. Retrieved 2010-10-07.
  16. ↑ Stacy Stewart (2010). "Tropical Storm Otto Discussion 7". National Hurricane Center. Retrieved 2010-10-07.
  17. ↑ Eric Blake (2010). "Tropical Storm Otto Discussion 9". National Hurricane Center. Retrieved 2010-10-08.
  18. ↑ Todd Kimberlain (2010). "Hurricane Otto Discussion 10". National Hurricane Center. Retrieved 2010-10-08.
  19. ↑ 19.0 19.1 Stacy Stewart (2010). "Hurricane Otto Discussion 12". National Hurricane Center. Retrieved 2010-10-08.
  20. ↑ Todd Kimberlain (2010). "Hurricane Otto Discussion 14". National Hurricane Center. Retrieved 2010-10-09.
  21. ↑ Todd Kimberlain (2010). "Hurricane Otto Discussion 15". National Hurricane Center. Retrieved 2010-10-09.
  22. ↑ Stacy Stewart (2010). "Tropical Storm Otto Discussion 16". National Hurricane Center. Retrieved 2010-10-09.
  23. ↑ Robbie Berg (2010). "Tropical Storm Otto Discussion 17". National Hurricane Center. Retrieved 2010-10-10.
  24. ↑ Michael Brennan (2010). "Tropical Storm Otto Discussion 18". National Hurricane Center. Retrieved 2010-10-10.
  25. ↑ Michael Brennan (2010). "Tropical Storm Otto Advisory 18". National Hurricane Center. Retrieved 2010-10-10.
  26. ↑ 26.0 26.1 Staff Writer (2010-10-08). "Tropical Storm Otto lashes Caribbean". Associated Press. Retrieved 2010-10-07.
  27. ↑ Staff Writer (2010). "Tropical Storm Otto shuts down St. Kitts and Nevis". South Florida Caribbean News. Retrieved 2010-10-07.
  28. ↑ 28.0 28.1 Webmaster (2010). "Drenched again". The BVI Beacon. Retrieved 2010-10-06.
  29. ↑ 29.0 29.1 SJU Webmaster (2010). "Record Rainfall 2010 San Juan". National Weather Service. Retrieved 2010-10-09.
  30. ↑ Toni Nicholas (2010). "We will build a stronger, better Dennery". St. Lucia STAR. Archived from the original on 2014-01-03. Retrieved 2014-01-03.
  31. ↑ Kayra Williams (2010). "Dennery Disaster". St. Lucia STAR. Archived from the original on 2014-01-03. Retrieved 2014-01-03.
  32. ↑ 32.0 32.1 Staff Writer (2010). "Red Cross responds to St Lucia floods". Caribbean 360. Retrieved 2010-10-15.
  33. ↑ Cherisse M. Sutton-Jeffer (2010). "Heavy rains, high winds in SKN disrupts residents' daily routine". SKNVibes. Retrieved 2010-10-08.
  34. ↑ 34.0 34.1 Joy Blackburn (2010). "Storm pummels St. Croix". Daily News Staff. Retrieved 2010-10-07.
  35. ↑ Joy Blackburn & Aldeth Lewin (2010). "Otto's onslaught spreads havoc". Daily News Staff. Retrieved 2010-10-08.
  36. ↑ Constance Cooper (November 6, 2010). "Obama declares Hurricane Otto was a disaster for V.I.". Virgin Island Daily News. Retrieved November 24, 2010.
  37. ↑ Staff Writer (2010). "A Flash Flood Watch remains in effect until 6 PM today". Virgin Islands News Online.
  38. ↑ Staff Writer (2010). "Flash Flood Warning Discontinued". Department of Disaster Management. Retrieved 2010-10-08.
  39. ↑ CNN Wire Staff (2010-10-10). "Virgin Islands dry out after Otto's wrath". CNN. Retrieved 2010-10-10.
  40. ↑ Staff Writer (2010). "British Virgin Islands: Governor McClary revokes state of emergency". Government of the United Kingdom. Retrieved 2010-10-19.
  41. ↑ Staff Writer (2010). "Otto Floods Virgin Islands and Puerto Rico". Associated Press & weather.com. Retrieved 2010-10-07.
  42. ↑ Staff Writer (2010). "Statement by Premier O'Neal - Tropical Storm Otto". GIS. Archived from the original on 2014-01-03. Retrieved 2010-10-21.
  43. ↑ Staff Writer (2010). "Road network damage put at over NAf 1.5 M". The Daily Herald. Retrieved 2010-10-19.
  44. ↑ "Les dégats d'Otto" (in French). Orange Caraibe. 2010. Retrieved 2010-10-11.
  45. ↑ David M. Roth (2010). "National Oceanic and Atmospheric Administration Puerto Rico Rainfall Map". Hydrometeorological Prediction Center. Retrieved 2010-10-15.
  46. ↑ Frances Rosario (2010). "Cerradas cuarenta carreteras por las lluvias" (in Spanish). El Nuevo Dia. Retrieved 2010-10-07.
  47. ↑ Staff Writer (2010). "6.5 millones en daños en carreteras" (in Spanish). Cyber News. Archived from the original on 2010-10-12. Retrieved 2010-10-11.
  48. ↑ Reinaldo Milán (2010). "Por el coletazo de Otto: Cuantiosas pérdidas en agricultura" (in Spanish). La Perla del Sur. Retrieved 2010-10-13.
  49. ↑ Joel Ortiz Rivera (2010). "Familias incommunicadas en Arecibo, Ponce y Cayey" (in Spanish). El Nuevo Dia. Retrieved 2010-10-07.
  50. ↑ Joel Ortiz Rivera (2010). "Más carreteras cerradas, 45,000 sin agua y sobre 120 refugiados" (in Spanish). El Nuevo Dia. Retrieved 2010-10-08.

External links

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