Complex sentence: The storm moved off the coast of New Jersey on March 31 and began rapidly strengthening and intensified air began rising vertically around the storm at a very rapid rate which cooled in the atmosphere and as a result the rain changed into heavy snow.
Split into simpler sentences: The storm moved off the coast of New Jersey on March 31 and began rapidly strengthening. As the storm intensified, air began rising around the storm at a very rapid rate which cooled in the atmosphere and caused the rain to change into heavy snow.