Weather Trivia - Snow in May

This week's question involves May 21's crazy weather. It actually snowed during the downpours in some areas.. at 45 degrees!! How can that happen?

ANSWER: A very cold pool of air moved in above, and thunderstorms erupted at the same time. As you can see by a typical thunderstorm structure to the left, warm air is drawn into the thunderstorm ahead and from the sides of the approaching storm. However, JUST ahead of, and accompanying rain, there is a DOWNDRAFT of cold air from above. This often results in what is known as a "microburst" which is a cold rush of air down that spreads out at speeds up to 100mph when hitting the ground causing tornado like damage. This area of the storm is sometimes accompanied by hail, large chunks of ice that are blowing around up and down in the top of the thunderstorm, getting bigger and bigger until they fall as ice out of the cloud. But snow??? Rare, but it happens in the "near winter" season. If the downdraft is strong enough, it will simply accompany huge snowflakes that form which rush down from the cloud and don't have time to melt, even if the temperature near the ground is 45-52 degrees. That is why there is snow on record in places like Rochester, NY in August as an example, and why it snowed in Harvard, Ma. briefly last weekend (5/21) in the Boston area! CLICK ON THE IMAGE, ASIDE FROM THE COLOR, IT IS HAND DRAWN BY WEATHER EXPERT/METEOROLOGIST/PROFESSOR JEFF HABY.