Initially, Joe moved northwest, but began to turn to the west-northwest, anchored by a subtropical ridge to its north.

[nb 1] The storm weakened rapidly over land, but re-intensified over the open waters of the South China Sea.

In Vietnam, 130 people were killed, 300,000 were directly affected, 165,000 lost their homes, 50,000 acres (20,000 ha) of rice paddies were flooded.

[2][nb 2] Less than four hours later, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert (TCFA).

On July 16, a Hurricane Hunter aircraft found a weak surface circulation and minimum sea level pressure of 1006 mbar (29.7 inHg).

Initially, the low- and mid-level circulations were not vertically stacked, with the low-level center exposed from the deep convection.

By 00:00 UTC on July 17, the surface center and the deep convection moved closer together, prompting the JTWC to classify the system as Tropical Depression 09.

[4] Meanwhile, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) also monitored the storm and assigned it with the local name Nitang.

[6] The depression began to develop at a quicker pace, and early on July 18, the JTWC upgraded it to a tropical storm.

[6] Joe then began to move on a constant and brisk westward course that it would maintain for the rest of its life in response to an unusually strong subtropical ridge that was east of its climatological position and to the north of the cyclone.

[2] At midday, hints of an eye became apparent on satellite imagery,[6] which led to the JTWC and JMA upgrading Joe into a typhoon.

At 00:00 UTC on July 22, the JTWC estimated that Joe attained a secondary peak of 170 km/h (105 mph) based on a Dvorak classification of T5.0.

Despite maintaining its structure[1] as it tracked over the Leizhou Peninsula, the storm weakened as it entered the Gulf of Tonkin[6] and approached the coast of Vietnam.

[4] Both the JTWC and JMA agree that Joe had winds of 130 km/h (80 mph) when it moved ashore near Haiphong in Vietnam later on July 22.

A minimum pressure of 1001.2 mbar (29.57 inHg) was recorded at the Hong Kong Royal Observatory (HKO) early on July 22.