The weather in the last 3 – 4 weeks has to put it mildly(sic) being playing havoc with the training and racing programmes of runners. And without doing the research I imagine that a large number of  scheduled individual  road events as well as the weekly Park Runs here in the South East have had to be cancelled for health and safety reasons in terms of risks on the course and the risks of actually getting to and from locations.The Big Beast from the East has been and gone and we are currently experiencing a much less disruptive beastie but one which is still causing cancellations of events.These weeks must have been particularly frustrating for spring marathoners who have been unable to build on their mileage base at a critical point in their training programme and perhaps have missed a targeted half marathon or 20 mile race. The temptation understandably may have been and may still be to try to make up for lost mileage by increasing distance/duration of weekly endurance runs in the weeks remaining before the planned marathon. Wrong thing to do as it will  undermine all the good work to date and could lead to over use injuries. Best advice is simply to carry on with the existing programme as is and make sure that the taper down period (ideally three weeks) is as originally planned and hopefully you will go into the big race with a positive mojo.