I would guess the line of snow is following the line of the Chiltern hills (it normally does)?
Monarch Scheduled said the recent cold snap in the UK had seen the British public ‘leaving in their droves’, with Tenerife and Lanzarote proving particularly popular.
Monarch carried 180,060 passengers on its scheduled services last month, 8.4% more than in January 2008, while load factor rose by 2.3pp to 75.8%.