[6][7] Late on the same day, JTWC upgraded the system to a tropical storm and designated it as 08W for an increase in organisation of the low-level circulation centre.

[8] The JMA upgraded the system to a tropical storm and named it Neoguri early on July 4, when a microwave imagery revealed that an eyewall was developing.

[9][10] At 09:00 UTC, the JMA upgraded Neoguri to a severe tropical storm, and then to a typhoon only three hours later, when the system continued tracking northwestwards along the southern periphery of a deep subtropical ridge.

[13] On July 5, Neoguri rapidly deepened and consolidated as curved banding wrapped tighter into a ragged 25 nmi (45 km; 30 mi) eye, owing to the robust all-around outflow.

[15] On July 6, the eye of Neoguri became highly symmetric and attained a large size with a diameter of 35 nmi (65 km; 40 mi), when the system was still tracking west-northwestwards along the southern periphery of a deep-layered subtropical ridge to the north.

[18] Simultaneously, JMA analysed that Neoguri had reached peak intensity, with ten-minute maximum sustained winds at 95 knots (175 km/h; 110 mph) and atmospheric pressure at 930 hPa (27 inHg).

Under the influence of a very favourable environment, the system had an expansive areal coverage as tightly curved deep convective bands, mostly feeding from the southern flank, wrapped even tighter into the expanding and nearly annular eye.

[20] However, the deep convection of the northwestern flank was almost eroded at noon, yet the round 40 nmi (75 km; 45 mi) eye maintained very well, prompting JTWC downgrading Neoguri to a typhoon late on the same day.

[21][22] Although a digging mid-latitude trough was amplifying the upper-level poleward outflow and helping to maintain the intensity, it increased subsidence along the northwestern quadrant of Neoguri, which significantly hindered the development and caused a weakening trend.

[27] Early on July 9, increasing vertical wind shear along the northwestern quadrant of Neoguri made deep convection erode very significantly.

[28] Soon, JMA downgraded the system to a severe tropical storm when sharply turning eastwards, and cold stratocumulus clouds were streaming into a defined but elongating low-level circulation centre.

[29][30] JTWC downgraded Neoguri to a tropical storm at noon, when the system was tracking along the periphery of the subtropical ridge modified by an approaching mid-latitude trough.

[47] The typhoon's passage pulled a warm air mass over Japan, resulting in a widespread heat wave with temperatures across eastern Honshu and Hokkaido rose to their highest levels in 2014.