The Nor'west Arch was written as a memorial to the victims of the February 2011 earthquake in Christchurch, New Zealand. The earthquake struck at 12:51pm on 22 February with a magnitude of 6.3 at a shallow depth of 5km. This caused widespread destruction across Christchurch and dozens of buildings suffered catastrophic damage. 115 of the 181 victims from that day were in the Canterbury Television (CTV) Building, which failed to withstand the intensity of the quake and collapsed within a short period, trapping many inside. This was the second significant quake to the hit the Canterbury region, the first being at 4:35am on 4 September 2010, approximately 40km west of the city centre. This also caused widespread damage but in contrast to the February 2011 earthquake there were no fatalities. This has been largely attributed to the time of day that it occurred.

Farr has dedicated this work to Rachel Conley, a friend who died in the earthquake. He also wishes to acknowledge Brian Poole for proposing the title The Nor'west Arch.

After writing the work for brass band, Farr then adapted The Nor'west Arch for orchestra. The orchestral version was premiered by Queensland Symphony Orchestra on 23 September 2011 in remembrance of victims of the floods in Queensland which claimed 38 lives between December 2010 and January 2011.

The title of this work has multiple meanings. The 'nor'west arch' is a weather pattern seen on the east coast of New Zealand's South Island, where an arch of high cirrus cloud appears over the Southern Alps mountain range in an otherwise clear blue sky. It is accompanied by a strong hot northwesterly wind known locally as 'the nor'wester'. This characteristic wind and cloud combination is uncommon during winter and its increasing frequency usually heralds the change of season into spring – a time of year synonymous with renewal of life and feelings of optimism. This feeling of hope and optimism was major factor in the commissioning of this work – it is intended to both memorialise the tragedy while also looking to the future as the city rebuilds. The 'arch' part of the title also alludes to part of the iconic Christchurch Cathedral that was significantly damaged in the earthquake.