Pat reached its peak strength early on February 10 as a severe tropical cyclone with winds of 140 km/h (85 mph) and a barometric pressure of 960 mbar (hPa; 28.35 inHg).
With above-average sea surface temperatures, stemming from a moderate-strength El Niño, multiple low-pressure systems were able to develop across the region.
An unusual spree of tropical cyclogenesis in rapid succession ensued, including four hurricane-strength storms: Oli, Pat, Rene, and Tomas.
[5] On February 6, the Fiji Meteorological Service (FMS) began monitoring a tropical depression, dubbed 09F, well to the northeast of the Samoan Islands.
Environmental conditions in the area, including low wind shear, high ocean heat content, and upper-level outflow, favored cyclogenesis.
[8] Steady improvement of the system's convective structure ensued and early on February 7, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert.
Based on increasing Dvorak numbers,[14] the JTWC assessed Pat to have reached hurricane-intensity by 06:00 UTC on February 9.
[12] The system became annular in nature on February 10, characterized by a lack of prominent banding features and uniform convection which surrounded its 19 km (12 mi) wide eye.
[12] At the same time, the JTWC assessed Pat to have been a Category 2-equivalent on the Saffir–Simpson hurricane scale with one-minute sustained winds of 165 km/h (105 mph).
[12][18] The storm rapidly weakened amid strong shear, with the center being left completely exposed early on February 11.
A solitary band remained along the south side of the storm by that time,[19] and the FMS no longer considered it a tropical cyclone after 06:00 UTC.
[12] The lone band of convection dissipated later that day and with no residual thunderstorm activity, the skeletal low turned westward in response to westerly flow.
Strong wind warnings were raised for Pukapuka, Nassau, and Penrhyn on February 8; however, they were dropped later that day as Cyclone Pat moved away.
[30] The aforementioned warnings were allowed to expire once Pat cleared the Cook Islands on February 11 and was no longer a threat.
[32] The Cook Islands Chapter of the Red Cross took early action with Cyclone Pat and began stockpiling relief supplies on February 9.
[38] Passing directly over Aitutaki on February 10, Pat produced wind gusts in excess of 185 km/h (115 mph) making it one of the most powerful storms ever experienced by residents on the island.
[40] Aitutaki Mayor Tai Herman claimed the winds to be much stronger, with gusts up to 240 km/h (150 mph) during the worst of the storm.
[3] In accordance with the FRANZ agreement,[55] the Government of New Zealand made an initial donation of NZ$350,000 for recovery efforts prior to the formal request for assistance on February 13.
The NZDF priority was repair of schools and hospitals, though they assisted the Red Cross with clearing debris, restoring power, and setting up temporary shelters for affected residents.
[56] An extensive repair and recovery plan was enacted by the Government of the Cook Islands within a month of Cyclone Pat, which covered agricultural, infrastructural, and societal sectors.
Financial restraints hindered the expected progress of this operation, with more than two-thirds of it not being funded by the final plan report on March 4.
Since the majority of the island's electrical grid was destroyed, an earlier plan to convert the network to underground cables was accelerated due to a convenience factor.
[44] The presence of dead vegetation left behind by the storm created fire hazards across the island, prompting the government to issue a ban on burning.
[64] Mayor Tai Herman feared that survivors would consider selling their homes and leave the Cook Islands altogether.
[63] The government enacted a three-month psychological support plan accordingly to help residents cope with the disaster and maintain social integrity among victims.