[4][2] Around this time, the Chilean Navy Weather Service began including the storm in their High Seas Warnings, continuing this until 4 May.

[4] During this time, the system encountered sea surface temperatures about 1 °C (1.8 °F) above average and low wind shear, due to an extremely strong El Niño event, allowing the storm to organize further.

[1] On 2 May, the storm reached its peak intensity, with maximum sustained winds of 72 km/h (45 mph; 39 kn),[4][nb 1] and a minimum low pressure of 993 hPa (29.32 inHg).

[7][8][9][10] Tropical cyclone formation in this extreme part of the Southeast Pacific is so rare that no warning agencies have yet been assigned to the region east of 120°W.

[1] Katie formed during an extremely strong El Niño event; the abnormally-warm waters 1 °C (1.8 °F) above average and low wind shear across the region may have contributed to the system's rare formation.