The Weather of November 2003

    November 2003 was wetter than normal. The monthly rainfall of 50.1 millimetres was some 40 percent above the normal figure of 35.1 millimetres. The accumulated rainfall since the beginning of the year is 1 941.9 millimetres, about 11 per cent below the normal figure of 2 187.0 millimetres for the same period.

    A broad ridge of high pressure brought sunny weather to Hong Kong in the first six days of November 2003. Under light winds, haze occurred on 2 November. The visibility inside the Victoria Harbour fell to 1800 metres while that at the Hong Kong International Airport dropped to 1000 metres, setting a new record of low visibility for haze in Hong Kong. It was very dry on 3 November and the minimum relative humidity of 31 per cent recorded that morning was the lowest so far this year. With long hours of sunshine during the day, the temperature rose to a maximum of 29.6 degrees on that day, the highest of the month.

    A moist easterly airstream arrived in the afternoon of 7 November, bringing some light rain patches to Hong Kong. Rain became more frequent the next two days when a cold front approached and passed through the south China coast. The drier air behind the cold front eventually cleared the rain and cloud on 11 November. Under the dominance of the northeast monsoon, cool and dry weather continued for a few days. There were reports of haze on 15 November in light wind conditions.

    When Nepartak entered the South China Sea on 14 November, it intensified into a severe tropical storm and moved in the general direction of Hainan. The rainbands associated with Nepartak drifted towards the south China coast on 16 November, bringing rain to Hong Kong in the ensuing four days.

    Another cold front crossed the coast of South China on 21 November and brought cooler weather to Hong Kong. A trace of rainfall was recorded the next day but the clouds associated with the cold front dispersed quickly on 23 November. The continental airstream behind the cold front maintained generally fine and dry conditions in Hong Kong throughout the rest of the month. Under light winds, it was hazy from 24 to 27 November. With a replenishment of the northeast monsoon, the temperature fell to 13.9 degrees on the morning of 30 November, the lowest recorded so far this winter.

    A total of 3 tropical cyclones occurred in the western North Pacific and the South China Sea in the month. 

    Details of issuance and cancellation of various warnings/signals in the month are summarized in Tables 1.1 to 1.3.  Monthly meteorological figures and departures from normal for November are tabulated in Table 2.