Cloud depiction problem

When at an airport where weather conditions are supposed to be overcast, the weather seems to depict itself properly. However, if I wait a few minutes(can be as little as two minutes) the sky conditions sometimes change into something that isn't accurate. For example, I started a flight in Boston. The weather conditions as of right now are overcast and light snow. The sim depicted the overcast skies the way they should have looked,but that realistic depiction changed as I was setting up my aircraft. What happened in this case was the sky remained overcast, but with a huge area of blue sky. Climbing out of the airport I did not go through any cloud layers whatsoever either. Even though according to the current conditions there are supposed to be clouds at 2300ft. The METAR both on the program and in the real world match, so I cant understand why this keeps happening. So far every flight I've flown into or out of an overcast area ends up "clearing up" into a partly cloudy sky or remains partially overcast with a huge area of blue sky. I also never seem to go through any thick overcast cloud layer. Seems I always end up with broken skies after reaching a thousand feet or so. Also If it calls for rain a lot of times there will be mostly blue skies, and a few clouds. Hope to have this solved its getting rather irritating.