Hurricane Lee, the 12th named storm of the 2023 Atlantic hurricane season, will continue on its north-westwards trajectory across the Atlantic Ocean this week. Lee rapidly developed into a category 5 hurricane last week, packing maximum sustained winds of almost 155mph (250km/h) on Friday. By Sunday, this had fallen closer to 105mph, which is classed as a category 2 hurricane.
Lee will continue to move to the north of Puerto Rico and the Dominican Republic, causing dangerous surf and rip currents across Bermuda and the US east coast this week. The hurricane’s intensity is fluctuating at the time of writing, but it is forecast to strengthen again early this week. The National Hurricane Center is predicting maximum sustained winds of 115 knots (around 130mph) and gusts of 140 knots. Towards the middle of this week, atmospheric conditions will cause Lee to gradually turn northwards. There is significant uncertainty on the speed of Lee’s movement beyond this, with its effects potentially being felt across the north-eastern US and Atlantic Canada towards the weekend.
Meanwhile, record-breaking temperatures across northern Europe will gradually return closer to the seasonal average through this week. Temperatures across the UK exceeded 30C for seven days last week, making it the longest September heatwave on record, surpassing the previous record by four days. In the UK on Saturday, the hottest temperature of the year so far, of 33.2C, was recorded at Kew Gardens in London. And in France, Météo France placed 14 departments on a tier-three orange warning for heatwave conditions, the first time this has occurred in September. Temperatures will begin to fall closer to average this week as cooler air spreads south-eastwards.
Extreme rainfall is expected across parts of South America through this week. The state of Rio Grande do Sul, in southern Brazil, and large parts of Uruguay could experience daily rainfall totals between 40mm and 60mm, but with a peak of up to 100mm possible on Tuesday as south-easterly winds bring persistent heavy rain from the South Atlantic Ocean. Cumulative rainfall totals could peak at about 120mm to 150mm by the end of this week.
