1913.] BAILIAVICK RAINFALL. 71 



below the normal. At Sark, for 1 9 days — from the 10th to 

 the 28th — the only rainfall was O'Ol in. This fell on the 

 17th. The same 19 days gave a total of 0'04 in. both at Les 

 Blanches (Guernsey) and at Alderney. 



The thunderstorm, without doubt the severest visitation 

 of the kind since that of June 8th, 1911, when " Moutville " 

 at the Yardes was gutted, occurred on Wednesday, the 30th. 

 At Guernsey the storm prevailed for seven hours — from 2 to 

 9 a.m. — and was extremely violent from 5 to 7 o'clock. In 

 the 2-| hours from 5 to 7.30 no less than 2'09 in. of rain and 

 hail fell at Les Blanches and proved to be the second heaviest 

 rainfall of the 20 year period, 1894-1913. The one bigger 

 downpour was 2*42 in. on Oct. 2nd, 1904. At Sark the storm 

 was reported in the Evening Press of August 1st, as follows : 



"On Wednesday morning a severe thunderstorm passed over the 

 island. About 5 a.m. loud rumblings of thunder were heard in the 

 south-west. Kain began to fall. It soon became apparent that Guernsey 

 was in the centre of the storm. Gradually it moved onwards and from 

 6 to 8 continuous peals of thunder were heard, the lightning then being 

 very vivid. Rain fell in torrents. From 7 to 7.30 the storm was at its 

 worst." 



At Alderney, where the lightning did damage, the visita- 

 tion is thus described in the Star of August 1st : 



" Alderney was visited by a thunderstorm of unusual severity on 

 Wednesday. As early as five o'clock in the morning the distant roll of 

 thunder was heard away to the southward. About 10 a.m. it broke over 

 the island and for over an hour it was severe, indeed flash and thunder 



were simultaneous Torrents of rain fell during the storm, 



and continued practically the whole day. It was wanted for the grass, 

 but the corn has suffered somewhat." 



The above paragraphs are interesting, giving as they do 

 particulars of the gradual approach to the islands, and 

 passage, of this violent electrical disturbance. The move- 

 ment of the storm must have been roughly from S. W. to N.E., 

 for as we have seen it only broke over Alderney at 10 a.m. 

 and Mr. Picot's returns show clearly that no rain fell there 

 until after nine o'clock. At Sark and Guernsey on the other 

 hand the whole of the thunderstorm rain fell prior to 9 a.m. 

 Gauged by the rainfall alone the storm seems to have been 

 worse at Guernsey than elsewhere, for in striking contrast to 

 the 2*09 in. measured at Guernsey (Les Blanches) the amount 

 at Sark was 0*80 in. only, and at Alderney 0*87 in. As the 

 rainfall day ends at 9 a.m. the above amounts are registered 

 for Guernsey and Sark against the 29th, and for Alderney 

 against the 30th. 



August was cold during the first half and very dry up to 

 the end of the third week. Thunderstorms of moderate inten- 

 sity in the last week gave the month's heaviest rainfall. 



