Radar image of typhoon Vicente passing just southwest of Hong Kong at 2:24 a.m. local time (July 24) or 2:24 p.m. EDT (July 23). (Hong Kong Observatory)

Maximum sustained winds have reached almost 140 mph (120 knots), the equivalent of a category 4 hurricane.

The Joint Typhoon Warning Center predicts the storm, moving over very warm waters (30-32 degrees C or 86-90 F) and beneath favorable upper level winds, will maintain intensity until coming ashore in Southern China at 8 a.m. Tuesday morning (Hong Kong time), the equivalent of 8 p.m. tonight in the eastern United States.

Live radar plainly shows Vicente’s intense outer bands lashing Hong Kong with a well-defined eye just to its southwest. The storm’s strongest winds and most severe tidal surge are likely to occur southwest of the city in southern mainland China, but squally, hurricane-type conditions are possible in the city itself. Accuweather reports an 83 mph wind gust was recorded.

Satellite view and track forecast for typhoon Vicente (University of Wisconsin-Madison,Cooperative Institute for Meteorological Satellite Studies)

Reuters provided the following information about actions that go into effect when a typhoon of this severity moves into the city:

Financial markets, schools, businesses and non-essential government services close when any No. 8 or above signal is hoisted, posing a disruption to business in the capitalist hub and former British colony that returned to Chinese rule in 1997.

The Hong Kong Observatory said it expected the No. 10 signal to remain in force overnight, meaning markets could be shut down in the morning.

Activation of the No. 10 signal is a rare occurrence according to the Hong Kong Observatory (HKO).

“From 1946 onwards, only 13 typhoons succeeded in issuing the No. 10 signal,” HKO said on its website.

Link: Tracks of Hong Kong No. 10 signal typhoons

The most recent No. 10 signal to be issued in Hong Kong was for Typhoon York in 1999.