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At 1435K the wind changed from north-east to a short south-west squall of 34 m.p.h. Rain amounting to 15 points fell in five minutes, after which sun came out and the wind returned to the north-east. During the shower at the Bureau there was only a little hail the size of which was about normal, none being larger than one half to three-eighths of an inch. Mr. Fitzgerald, our rainfall observer at Liverpool, reported 29 points of rain in a short period, but no hail fell in the district. Four miles to the west of Liverpool no rain whatever was recorded, while the locality four miles to the east was on the fringe of the storm. At Mascot, up till noon, there was only scattered large cumulus and a trace of Ac., but towards 1300K, conditions had become cloudy and the storm struck the aerodrome at 1425K with heavy thunder and hail lasting until 1450K. The highest wind gust was 33 m.p.h from the south-west at 1440K, and a total of 39 points of rain fell during the storm. The change in the meteorological elements at Mascot are shown in Fig II. and II. Capt. S. Owen of Butler Transport who was carrying out gliding exercises in the Mulgos district states the origin was apparently in the Camden district, as he could see the build up of cloud going on in that area during the forenoon. Mr R.R.C. Porter, Observer at Mascot, saw the cloud which gave rise to the storm forming at approximately 1000K between approximately Fairfield and Liverpool. It had then reached a fairly advanced stage of development with a peculiar formation.
The storm broke over Rose Bay at 1435K and lasted until 1448K. Rainfall amounted to 25 points. Hail was up to 2 inches in diameter (billiard ball size). The maximum wind gust was 46 m.p.h from the south, the wind being fresh north-east before and after the storm. The hail made holes in the hanger roof at the Flying Boat Base. Samples and or descriptions of actual hailstones available to the Weather bureau are as follows:–
Mr R.C.L. White, Weather 'Officer'.
Samples from Edgecliff 2.1/16 inch diameter with four layers
Mr. Lurie (southern suburb)
Oval shaped 7" x 4" at least 12 layers.
