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the five months to 31 March, only 29.2 mm of rain fell, thelowest recorded for the period.Typhoon Dinah stayed over the northern part of theSouth China Sea for a week in September, and the Standbysignal, No. 1, was hoisted for a record of more than 124hours.In the wake of the dry weather, water restrictions wereimposed on 1 June 1977. Full supply was resumed on 18April 1978.It was also a year of tropical cyclones, with eightapproaching Hong Kong.Few tropical cyclones have approached Hong Kongtwice, and Severe Tropical Storm Agnes (24-30 July 1978)was the only one for which gale signals were hoisted on twoseparate occasions. Fortunately for Hong Kong, Agnes wasnot particularly powerful, with maximum sustained windsin the harbour of only 41 knots.Agnes was, however, a wet storm, bringing Hong Kong519 mm of rain. Agnes was slow moving, and the rain,while not particularly intense, persisted for a long period.Because of its unique behaviour, Agnes is worth describingin some detail.On 22 July an area of low pressure formed over thenorthern part of the South China Sea. By the earlyafternoon of 24 July, satellite photographs showed that thelow pressure area had become a tropical depression.At 2 pm it was centred just over 300 miles south of HongKong, moving towards the China Coast at 9 knots.At 7.30 am on 25 July, the storm was 180 miles southsoutheastand the Standby signal, No. 1, was hoisted.Later on 25 July, the depression intensified into a tropicalstorm, and satellite photographs showed that the spiral rainbands had become more organised, though the eye wasdiffuse.As it moved towards Hong Kong, the No. 1 signal wasreplaced with the No. 3 Strong Wind Signal at 10.50 pm on25 July.83