1903.] C. Little — Himalayan summer storms. 249 



The occasions on which pressure fell along the Himalayan range 

 were June 9th, June 17th, July 8th, July 18th. 



The disturbances which passed along the Himalayas about the 9th 

 and 17th June appear to have commenced in the north-west and ad- 

 vanced eastward, and they were probably followed by a north-westerly 

 wind in the upper atmosphere. My reason for thinking that the upper 

 wind was north-westerly during the latter part of June is based on the 

 direction in which thunderstorms moved over Bengal during that period. 

 In a paper read by me at the last meeting of the Society I stated that 

 thunderstorms during the past hot season had been abnormal in several 

 respects, the most noticeable being that instead of approaching from the 

 usual north-westerly direction they had without exception come from 

 the west. After the middle of June, thunderstorms continued but they 

 no longer moved from the west. Instead they had become, so far as di- 

 rection went, typical nor'westers. 



A storm of a very exceptional kind began over Orissa in the early 

 morning of the 11th June. It was of the thunderstorm type and moved 

 southward along the coast, causing squally weather in the north of the 

 Circars on the forenoon of that date and in the south in the afternoon* 

 I mention it in this connection as showing the existence of a northerly 

 wind in the upper atmosphere in that region. 



After a period of continuous low pressure over Northern India from 

 the 17th to the 22nd June, a general rise began along the hills and ex- 

 tended southward. This rise was probably accompanied by an increase 

 of velocity in the upper northerly wind, as a depression which was 

 beginning to form over the Bay, developed over the north-west angle, 

 moved into Chota Nagpur, and then recurved into Bihar and north 

 Bengal. The heavy rainfall at Cherrapoonjee between the 27th and 29th 

 June was caused by this storm, and the recurving was probably due to 

 the north- westerly wind aloft. 



The next occasion of disturbed weather in the Himalayan region 

 was between the 7th and 13th July, and that has been already discussed. 

 The last disturbance began about the 17th July and was very little felt 

 at the eastern end of the Himalayan range. The only indication is the 

 falling pressure in Assam on the 17th and the indraught up the Brah- 

 maputra valley. But in the centre and west of the range there were 

 important developments. Thunderstorms with heavy rainfall and 

 large changes of pressure occurred. This rainfall is very similar to the 

 rainbursts which occurred in Bengal last year, and it is difficult to 

 account for its occurrence by any series of changes then in progress in 

 India. A cyclonic storm was shown in the Indian Daily Weather Report 

 of the 18th, but, as stated under the heading of pressure in that report 



