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Under the influence of Typhoon Krosa and Super Typhoon Haiyan, the weather of November 2013 was wetter than usual. The total rainfall for the month was 83.1 millimetres, more than double the normal figure of 37.6 millimetres. The accumulated rainfall since January 1 was 2759.0 millimetres, about 16 per cent above the normal figure of 2371.6 millimetres for the same period. November was also gloomier than usual with 133.4 hours bright sunshine, about 26 per cent below normal. The monthly mean temperature of 21.7 degrees was slightly below the normal figure of 21.8 degrees.
Under the dominance of a ridge of high pressure over southern China, it was fine and dry in Hong Kong on the first day of the month. Meanwhile, Typhoon Krosa moved into the South China Sea that morning and edged closer towards the Guangdong coast during the next two days. Affected by the rain bands of Krosa, local weather became cloudy with a few showers on November 2 and 3.
As Krosa weakened and moved away from Hong Kong on November 4, bands of clouds and rain associated with the northeast monsoon moved in and brought a few rain patches to the territory on November 4 and 5. With clouds thinning out gradually, sunny periods appeared over the next four days.
Over the western North Pacific, Super Typhoon Haiyan moved westwards and swept across the central part of the Philippines on November 8. It weakened gradually into a typhoon over the South China Sea and made landfall over the northern part of Vietnam on the morning of November 11. Under the combined effect of Haiyan and the northeast monsoon, local weather became windy and cloudy with a few rain patches from November 9 to 11. After Haiyan weakened into an area of low pressure over Guangxi, the remnants of Haiyan and the intense northeast monsoon continued to bring windy and rainy weather to Hong Kong on November 12.
With the arrival of a replenishment of the northeast monsoon, local weather became slightly cooler on November 13 with a few rain patches. As the clouds broke, the weather became fine on the afternoon of November 14. Under the dominance of a dry northeast monsoon, generally fine and dry conditions persisted over the territory over the next four days, before clouds returned to cover the coast of Guangdong on November 19 and 20.
Affected by a fresh to strong easterly airstream, it was mainly cloudy with light rain patches on November 21 and 22. Clouds thinned out with sunny periods during the day on November 23. Meanwhile, a cold front over central China moved southwards on November 24 and crossed the coast of Guangdong that night. Locally, the weather turned cloudy with a few squally showers during the passage of the cold front in the evening.
Under the influence of a dry northeast monsoon behind the cold front, the weather was cooler and dry on November 25 and 26. The weather stayed mostly fine at first on November 27, but soon turned cloudy with a few rain patches in the afternoon as an intense replenishment of the northeast monsoon reached the coastal areas of Guangdong. Affected by a cold airstream associated with the northeast monsoon, it became rather cool from November 28 to 30. The temperatures recorded at the Hong Kong Observatory fell to a minimum of 12.8 degrees on the morning of November 28, the lowest of the month. The weather was also fine and very dry on the last two days of the month.
Four tropical cyclones occurred over the South China Sea and the western North Pacific in the month.
Details of the issuance and cancellation of various warnings/signals in the month are summarised in Table 1. Monthly meteorological figures and departures from the normal for November are tabulated in Table 2.
Ends/Tuesday, December 3, 2013
Issued at HKT 18:30
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