Saturday 20th September
The drift of very warm, moist air from around the Azores region, on a brisk southwesterly breeze on Friday, gave us a very pleasant autumn day that saw the thermometer rise very high for early September reaching a peak of 25.0C at 14.57. This was a signifiant 6.0C above my long-term average and the warmest day since 25th August (27.5C). It was also a dry day that gave splendid sunshine in the afternoon during which time the UV level rose at its peak to the top end of ‘Moderate”.
The past night was also warm with a minimum of 13.1C just after midnight at 00.45, but instead of continuing to fall, as is usual in the early hours, it lifted to 13.8C for a couple of hours then rose to 14.4C by 08.00.
Saturday after dawn revealed thin cloud in the eastern horizon with the sun trying to break through whilst the thicker cloud continued to drift across from the west bringing misty conditions ahead of the next weather front that is likely to produce rain before midday.
The low pressure system currently sitting over the UK will slowly ease away towards Scandinavia on Saturday, which will allow the very large area of high pressure sitting just off the coast of Ireland to edge closer. This will mean the recent drift of warm, moist air from the Azores will be cut off resulting in temperatures dropping significantly on Sunday as the wind veers first into the west overnight then north on Sunday morning. The maximum in the very cool air, that originates around Iceland, will see the maximum perhaps 5C below the long-term average.
Storm Gabrielle is now forecast to strengthen and become a hurricane on Sunday, to the north of the Caribbean and east coast of America, however, it is forecast that swells generated by Gabrielle are likely cause life threatening surf conditions. The forecast track will see it slowly rotate clockwise into a northeasterly direction into the mid-atlantic.
Westonbirt Arboretum was planted in the heyday of Victorian plant hunting in the mid-19th century, as part of the Westonbirt House estate.