On July 3, conditions in the upper troposphere over the basin underwent significant changes with two upper-level troughs developing in the midlatitudes; of note was one which moved southward from Japan.

[4] Increasingly vigorous outflow, attributed to the cutoff low near Japan, enabled continued deepening of the cyclone over the next two days.

Following the typhoon's peak intensity, the cutoff low previously providing Rita with favorable outflow rapidly weakened.

[2] Simultaneously, the cyclone turned more westerly and slowed as an intensifying Typhoon Phyllis to its east began to influence Rita.

This channel, previously aiding the development of Typhoon Tess to the west, enabled Rita to attain winds of 175 km/h (109 mph) on July 18.

Another major shift in the typhoon's course took place that day as a ridge build over the Sea of Japan and imparted a more westerly track.

Upon moving over the East China Sea on July 21, an unusual set of conditions prompted Rita to turn southwest.

The two main factors in this were the presence of a low over Manchuria which resulted in slower forward movement and Typhoon Tess located 1,480 km (920 mi) east which pulled the storm south due to the Fujiwhara effect.

[3] Rita completed its cyclonic loop on July 25 and subsequently accelerated northward as it moved into a convergent flow region between the Manchuria low and the ridge near Japan.

The storm skirted the Korean Peninsula on July 26, passing near Jeju Province off the southwestern coast of South Korea, before moving over the Yellow Sea.

[4] Though judged to be extratropical by the JMA at this time, the China Meteorological Agency asserts that Rita remained tropical until its landfall in accordance with radar imagery and radiosonde observations.

[3] On July 8, a United States Air Force B-52 heading to Vietnam was caught in the circulation of Rita and crashed less than 280 km (170 mi) west of the storm.

[4] Although Rita remained well away from the Philippines, its tremendous circulation enhanced the southwest monsoon over Luzon for several days, particularly on July 17.

[4] Newspaper reports regarded it as the worst flooding since World War II, with 14 provinces along a 320 km (200 mi) swath north of Manila affected.

During this period, the highest winds measured across the archipelago was 178 km/h (111 mph) on Kume Island while the lowest pressure was 955.6 mb (hPa; 28.22 inHg) at the Marine Corps Air Station Futenma on Okinawa.

[23] Zaoshulin in the Huairou District of Beijing received 479.2 mm (18.87 in) of rain in one day,[24] which resulted in debris flows in mountainous areas and killed about 50 people.

[25] By July 19, President Ferdinand Marcos placed the National Defense and Social Welfare Departments on 24-hour duty and allocated $8.2 million in relief funds.

[16] An appeal was made by authorities on July 21 for an immediate airlift of food to an estimated 115,000 people in Tarlac Province feared to be starving after being isolated by the floods.

[26] On July 24, Marcos temporarily moved his office from Manila to Lingayen, Pangasinan in order to oversee relief operations more directly.

[15] Arriving on July 22, the 104-man-strong U.S. Army Disaster Area Response Team aboard the USS Tripoli began relief operations immediately.

Additionally, impatient victims tried to ransack trucks carrying supplies on July 24, forcing officials to fire warning shots in the air to dispel them.