The NASCAR race at Pocono was actually delayed because of poor weather, rain to be specific. NASCAR, and race car driving in general, is a very dangerous sport. Having the drivers drive on a wet race track will only increase the already high likelihood of an accident and more injuries.
Yes I think the race will be delayed because it has already been delayed. The race has started now but was originally delayed. Racing is dangerous and it seems to make sense to postpone for wet weather. There shouldn't be any other distractions for the drivers and anything that can be done to make the race safe should be done.
When it comes to the outdoors, mother nature is unpredictable. This is a fact that has ruined several outside events. If you have an event outside it is like playing Russian roulette on whether the weather is going to be agreeable or not. Nobody can predict it but we can get close.
Yes, the officials of the Pocono's race will delay or postpone the event due to poor weather. Forecasts for the upcoming event suggest that heavy rains and wind will force the racetrack to be almost unusable. With drivers racing at speeds well over 100 miles per hour, there is every reason to believe that the officials would favor safety and audience comfort over fool-heartily continuing the race in the rain.