In advance of Maria, the Japan Meteorological Agency issued warnings about potential landslides, overflowing rivers, and flooding in low-lying areas, as well as strong winds.

Several homes were flooded in Iwaizumi, Kamaishi, and Miyako, and a Level 5 emergency warning was declared for the Osanai and Kokuji regions in Kuji City, Iwate Prefecture.

[1] Later that day, the United States Joint Typhoon Warning Center (JTWC) began tracking it, noting the depression was in an environment with low to moderate wind shear, warm sea surface temperatures, and good equatorward outflow aloft.

[2] At 09:00 UTC on August 6, the JTWC issued a tropical cyclone formation alert on the disturbance, which was located 423 mi (682 km) north-northwest of Iwo Jima, along the eastern periphery of the monsoon gyre,[3] prior to it being designated as 06W.

[4] The development of a central dense overcast and a ragged eye feature signified its intensification into a tropical storm,[5] leading the JMA to name it Maria on August 7.

[6][7] Maria then turned northeastward, moving along the northwestern edge of a subtropical ridge, and intensified into a severe tropical storm on August 8 due to a favorable environment for development.

[10] Concurrently, the JTWC then reported that Maria had rapidly intensified into a minimal typhoon, with 1-minute sustained winds of 130 km/h (80 mph), due to strong equatorward and poleward outflow.

[13] However, satellite imagery later revealed that convection was wrapping around the system's defined low-level circulation,[14] and a partial eyewall developed in the western semicircle of the center.

[25] The East Japan Railway Company also announced the suspension of trips to Tōhoku, Akita, and Yamagata via the Shinkansen due to rainfall from Maria.