An ‘angry’ jet stream will fracture into two before joining forces with ex-Hurricane Ernesto to shake up Britain’s weather. ‘Complex’ weather systems will compete to bring wind and rain before another blast of sultry warmth. Perplexed meteorologists are once again scratching their heads over yo-yo-ing forecasts heavily influenced by the tropics. Hurricane Ernesto had last night strengthened off the US east coast where it will hitch a ride to the UK on a powerful jet stream. After a settled weekend, Monday will see gusty showers sweep in from the west before temperatures rise in the death throe…