Iune (2015)

Iune formed as a small low within an unusually strong monsoon trough in the central North Pacific. The system was first noted on 2 July about 800 nautical miles southeast of Hawaii and became a tropical depression at 0600 UTC 10 July about 650 n mi southeast of Honolulu. It turned northwest then west-northwest, strengthened to a tropical storm at 1800 UTC 11 July, and reached its maximum intensity on 11 July–12 July before weakening to a depression on 12 July and becoming a post-tropical remnant low by 1200 UTC 13 July. The remnant low continued westward south of the subtropical ridge, passed about 160 n mi south of Johnston Atoll on 14–15 July, and dissipated by 1200 UTC 17 July near the International Date Line.

Iune did not make landfall on any populated islands or coastlines while it was a tropical cyclone. The system remained over open water throughout its life; its remnant low later passed south of Johnston Atoll but caused no reported coastal impacts there.

The storm’s peak intensity was 35 kt (40 mph) with a minimum central pressure of 1004 mb, corresponding to a minimal tropical storm (well below hurricane strength). The official best track lists the maximum wind of 35 kt at 1800 UTC 11 July (with the same intensity into 12 July).

No storm surge reports are attributed to Iune, and there were no notable rainfall totals recorded from the cyclone at populated locations. There were no surface observations or ship reports of tropical-storm-force winds, and no coastal watches or warnings were required.

There were no reported deaths or damage from Iune. The cyclone was short-lived and small, and its impacts were limited to the open ocean. Forecasters noted they anticipated the system’s development several days in advance; initial short-term track forecasts had some error when Iune made an abrupt northwest turn soon after formation, but overall CPHC intensity forecasts performed reasonably well for such a weak, small system.