Sessional_Paper_1908 — Page 656

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Enclosure 1.

REPORT BY DIRECTOR OF OBSERVATORY.

The typhoon which struck the Colony on the night of the 27th to 28th July last was possibly formed on the 25th to the Eastward of the Balingtang Channel. But as this typhoon must undoubtedly be classed as one of small area, in the absence of any data from the Pacific, this cannot be certainly affirmed. There is, in any case, no evidence whatever of its existence prior to the 25th. On this day a slight fall of the barometer took place in Luzon and S. Formosa, although pressure remained slightly above the normal over both

areas.

On the morning of the 26th a sharp fall, amounting to just over a tenth of an inch since the previous day, was noted at Koshun (S. Formosa) 29.71, and at Aparri (N. Coast of Luzon) 29.69, and the wind circulation, a strong N.E. breeze at the former, and a light S. breeze at the latter station, gave evidence, in conjunction with pressure conditions over surrounding areas, of the existence of a depression in the Balingtang Channel. The position assigned to the centre on our Weather map was 19° N., 121o E., and information in accordance therewith was issued in Hongkong and the shipping notified by signals at 10.45 a.m.

The afternoon observations received from Koshun and Aparri indicated some move- ment of the depression to the Westward. The barometer had risen at both stations, the wind had veered to E., a strong breeze at Koshun (bar. 29.73) while a light S.W. air blew at Aparri (bar. 29.73),

High pressure lay over the Pacific between the Bonin and Loochoo islands on this day, an area of low pressure was situated over Manchuria, while conditions over S. China were practically normal.

The morning observations of the 27th showed a moderate increase of pressure in Luzon (Aparri 29.78, wind S.E., a light air, clear sky). The observations from Koshun did not reach the Observatory, but at Swatow the barometer read 29.71, wind N.E. force 1. In Hongkong, where pressure had given way two hundredths of an inch only, during the past. 24 hours and was below the normal by the same amount, the barometer at 10 a.m. read 29.75, wind E. force 1. At Gap Rock a gentle breeze blew from N.E. These observations faintly indicated the existence of the depression but gave no clue whatever as to its severe character. It was believed to be situated at that time about 300 miles to the S.E. of the Colony and notice to that effect was given, and the Red signals were hoisted at 12.15 p.m.

Pressure on this day had weakened slightly but was still high over the Pacific between the Bonins and Loochoos. The Manchurian depression had moved to the N.E. and a slight increase of pressure had taken place over N. China. In the South the only abnormal feature was the light N.E. wind along the S. coast of China.

Perhaps the best evidence of the existence of the typhoon was furnished by clouds. The morning broke fine, the sky being almost cloudless. Shortly after noon a bank of clouds of the cirro-stratus type was observed bearing S.E. by E., its advancing edge being at an altitude of about 30°. At 4 p.m. this pall had covered nearly the whole sky except just above the N.W. horizon where it was still clear. A few patches of alto-cumulus below it were seen to be coming from N.E. by E. in the afternoon. The direction however was backing, a significant fact. At 6 p.m. they came from N.E. by N. and it was then that the Black signals were hoisted.

The barometer, still only 0.02 inch below the normal at 4 p.m., now began to fall and the wind, which had been chiefly a light breeze from E. during the day, shifted to the North. Gap Rock at 4 p.m. reported "slight swell from S.E.", the wind there at the time being a gentle breeze from N.E. At the same hour Waglan reported a moderate breeze from E.N.E. At 7 p.m. it blew a fresh breeze from N.NE. at Waglan and a gentle breeze from N. at Gap Rock, the swell still being reported from the latter station as "slight from S.E.". It thus appears that sea swell in this instance had not outrun the advancing storm to any considerable distance. Rain commenced to fall at the Observatory at 8 p.m.