This weekend promises to bring another burst of heat to the UK, with Monday expected to be the hottest day of the year so far. However, the hot and humid weather will not be everywhere and will not last long. The sudden change in the weather is partly due to Tropical Storm Debby, which brought flooding rains to the eastern US. As well as bringing heavy rain, Debby also pushed very warm air to higher latitudes, thereby changing the position of the jet stream with impacts expected in the UK.
Downstream in the Atlantic, the jet stream pattern changes from straight to buckled, meaning it will be positioned to the north-west of the UK by Sunday. A southerly breeze will develop and very hot and humid air will be drawn up quickly from Spain and France. However, it will not be hot for everyone. The heat and high humidity will be concentrated on Lincolnshire, the Midlands, East Anglia, and South-East England, while Scotland and Northern Ireland will not be as warm but should remain dry.
The highest temperature of the year so far is 32°C recorded in London at the end of July, but that temperature could be exceeded on Monday. On Saturday, the temperature in the UK was average, but on Sunday, we will see temperatures jump up by four or five Celsius in England and Wales as the sun comes out. Timing will be crucial, as with the hottest air expected to arrive from France and Spain before the cloud, the temperature in South-East England could shoot up very quickly to 34°C on Monday.
For it to be considered a heatwave, the temperature criteria have to be reached for at least three days in a row. Tuesday will still be very warm in East Anglia and South-East England with temperatures up to 27 or 28°C. But next week, the jet stream pattern in the Atlantic will straighten again, and we will be back to more changeable weather with temperatures nearer normal.
Finally, it is worth noting that this summer has seen a few of these “heat spikes.” Over many years of presenting the national weather forecast, it has become apparent that it used to take three or four days of dry weather to lift the temperature to 30°C, but are things changing, and are these temperature rises happening more rapidly? It is difficult to quantify a shift like this, but it could be that we are seeing another impact on our weather patterns as a result of climate change
Read the full article from The BBC here: Read More
