page_title: Cyclone Nancy
section_title: Preparations
hierarchical_section_title: Cyclone Nancy / Preparations
caption_attribution_description: A strengthening Cyclone Olaf and a weakening Cyclone Nancy eye each other across the South Pacific in this Moderate Resolution Imaging Spectroradiometer (MODIS) image from February 15, 2005. As of the afternoon of February 15, Olaf was approaching Category 5 status, with sustained winds of 135 knots and gusts up to 165 knots. According to the Joint Typhoon Warning Center, waves were estimated to be as high as 47 feet. Although Nancy was a Category 4 storm in its early stages, by February 15, the storm had weakened. Sustained winds were 85 knots, with gusts up to 115 knots. Wave heights could be as high as 27 feet. Unlike Olaf, Nancy was predicted to weaken as it moved south over subsequent days. Predicting how two powerful storms will interact as they approach each other is a difficult task. Although it is unlikely that the two storms would join together “eye-to-eye,” to form a single massive storm, it is likely they could influence each other's speed and direction. When two storms are within about 1,000 kilometers of each other, their trajectories begin to be influenced by the large-scale atmospheric circulation of the other. For example, if one storm is much stronger than the other, the weaker storm may be tugged off course by the powerful processes that are drawing air into the larger storm. In some cases, this can result in one storm seeming to “orbit” the other. The interaction is called the Fujiwara effect, after a Japanese meteorologist who first described it. This image was made by combining observations form the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra and Aqua satellites. The part of the image that shows Cyclone Nancy was captured by Aqua MODIS, while the part that shows Olaf was captured by Terra MODIS.
context_page_description: Cyclone Nancy was the second in a series of four severe tropical cyclones to impact the Cook Islands during February 2005. Forming out of an area of low pressure on February 10, Nancy quickly organized into a small, but intense, cyclone. By February 14, the storm explosively intensified into a Category 4 severe tropical cyclone with winds peaking at 175 km/h and a minimum barometric pressure of 935 hPa. Over the following day, increasing wind shear rapidly weakened the cyclone and by February 17, it transitioned into an extratropical cyclone shortly before being absorbed by Cyclone Olaf.
  Already impacted by Cyclone Meena in early February, the Cook Islands sustained significant damage from Cyclone Nancy. Several homes were damaged and destroyed throughout the islands. Downed trees and power lines blocked roads and cut power and minor flooding was reported along coastal areas. Following the impact of the storm, the World Meteorological Organization retired the name Nancy in May 2006 and replaced it with the name Nat.
context_section_description: Upon being named Nancy on February 13, a gale warning was put in place for American Samoa. Later that day, four additional countries were placed under watches and warnings. A gale watch was declared for Samoa and strong wind warnings were raised in Tuvalu, Tokelau and the Cook Islands. On February 14, a tropical cyclone alert was declared for the southern Cook Islands. Additionally, Niue was placed under a strong wind warning. Later that day, Wallis and Futuna were placed under a strong wind warning. On February 15, a hurricane warning was issued for the southern Cook Islands as Nancy tracked through the archipelago.
  Already impacted by Cyclone Meena just a week prior, residents in the Cook Islands heeded warnings and evacuated to emergency shelters. Coastal areas where seawalls had been damaged or destroyed by Meena were of particular interest to warning centers and urged all people in the vicinity of them to evacuate to a nearby shelter. On Aitutaki, all preparations were completed by February 15. Tourists were relocated from hotels to one of six shelters set up throughout the island. An estimated 100 people reportedly evacuated to shelters out of the 2,000 that live on the island. Radio broadcasts urging people to move to shelters were broadcast all day and the local cyclone center had all staff on standby. Eight shelters were opened on Rarotonga by this time. All residents were evacuated from low-lying areas as large swells were anticipated to inundate those areas. Schools throughout the Cook Islands were closed prior to the cyclone and would remain closed for several more days. Many of the south Pacific islands were in a "critically dangerous situation" due to the quick succession of cyclones.
caption: Cyclones Nancy (right) and Olaf (left) on February 14
exif: {}