casualty celebrates 30 years on air with a special episode filmed in just one take with just one camera. and sarah has the weather. good morning. a mixed picture on the weekend. spells of sunshine. landy of blustery showers. plenty. all the details in 15 minutes. thank you. good morning. first, our main story. president trump s aide has resigned after days of public infighting at the white house and repeated failures by his administration to fulfil their key election pledges. mr trump has replaced his chief of staff reince priebus, withjohn kelly, a former general who s been in charge of the department of homeland security. one official said he d been hired with the goal of bringing more discipline to the white house. here s our north america correspondent, peter bowes. another tweet, another resignation, another day in the trump presidency. reince priebus is the latest to leave this job prematurely. reince priebus is the latest to leave thisjob prematurely. the shortest s