Standby Signal Number One could be issued on Tuesday
The observatory on Monday said it might issue the Standby Signal No.1 between Tuesday afternoon and Tuesday night, with Tropical Cyclone Yagi intensifying into a severe tropical storm.  It said Yagi would be within 800 kilometres of Hong Kong on Tuesday and then edge close to the coast of southern China.  It added there was a high chance Yagi would move towards the vicinity of the western part of Guangdong and Hainan Island and would further intensify.  Looking ahead, the observatory forecast Yagi could strengthen to a typhoon by Thursday.