After gaining organization, the system rapidly developed and intensified into a severe tropical storm and reached its peak intensity with a 10-minute maximum sustained winds of 100 km/h (62 mph) and a minimum barometric pressure of 985 hPa (29.1 inHg).

[1] Noting some organization within the system, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert (TCFA) early on July 1.

[5] Shortly after, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) upgraded the system to a tropical depression, assigning the local name Emong.

[9] Satellite imagery depicted convective banding wrapping tightly into Nanmadol's low-level circulation center (LLCC), prompting the JTWC to upgrade it to a tropical storm in their next advisory.

[12] The PAGASA also upgraded Nanmadol to a severe tropical storm in their final advisory on the system as it exited the Philippine Area of Responsibility.

[16] However, the JTWC assessed that Nanmadol reached its peak intensity as a Category 1-equivalent typhoon with 1-minute sustained winds of 120 km/h (75 mph) six hours later in a post-analysis report.

[17] Nanmadol maintained its peak intensity for several hours until just before July 4, when the system began curving eastwards and its satellite presentation deteriorated.

[21] By 21:00 UTC on the same day, the JTWC issued its final advisory on Nanmadol, mentioning that the system was embedded within the cold baroclinic zone, and had thus lost its tropical characteristics and transitioned into a cold-core low.

[26] The government dispatched a total of 12,000 rescuers, including police officers, firefighters and the Self-Defense Forces troops, in preparation for post-storm relief.

Heavy rains and strong winds disrupted numerous train services including the iconic Shinkansen, between Hakata and Kagoshima-Chuo in Kyushu.

[31][32] Evacuation advisories were issued to at least 20,000 residents due to fears of possible flooding and landslides, especially in the Niigata, Toyama and Nagano prefectures that had experienced rainfall accumulations of up to 300 mm (12 in) in the preceding hours.

[29] During July 12, the Japanese prime minister Shinzō Abe canceled a trip to Estonia for a European tour and instead visited devastated places over in the Kyushu region to view the damage and console residents.