The National Centre for Hydro-Meteorological Forecasting said that on the morning of August 7, a low-pressure area over the Gulf of Tonkin had strengthened into a tropical depression.
At 9.00 am, the centre of the tropical depression was in waters to the south-east of Bach Long Vi Special Zone. The strongest winds near its centre reached force 6, or 39-49kph, with gusts up to force 8.
Over the next 24 hours, the tropical depression is forecast to move slowly eastwards towards Hainan island, China. It is unlikely to strengthen into a storm and is not expected to make landfall in Vietnam.
The projected path of the tropical depression (Photo: NCHMF).
On Typhoon Dolphin, the China Meteorological Administration's National Meteorological Centre said that on the morning of August 7, the storm's centre was about 760km east of Wenzhou City, Zhejiang Province, China.
The strongest winds near the storm's centre reached 162kph, and it was moving west at 15-20kph. Its circulation remained very broad, with force 7 winds extending 420-450km from the centre, force 10 winds reaching 220-250km, and force 12 or stronger winds covering a radius of about 100km.
An NMC marine bulletin also said waves near the storm's centre could reach as high as 11 metres.
South Korea's meteorological agency, the KMA, assessed Dolphin as weaker than the NMC did.
At 9.00 am on August 7, the strongest winds near the storm's centre were about 144kph. The storm was moving west at roughly 26kph. According to the KMA, Dolphin could maintain winds of about 144kph on August 7-8 before beginning to weaken.
Japan Meteorological Agency also estimated Dolphin's winds on the morning of August 7 at about 144kph, with gusts of 198kph.
International meteorological agencies were broadly aligned on the storm's track, though differences remained over its intensity. The KMA and JMA estimated maximum winds at about 144kph, while the NMC put them at 162kph.