Jody Victor : We are happy to say "Spring has Sprung!" In Northeast Ohio it has been a wonderful beginning to a hopefully fine-weathered season. But it is Ohio, and the weather will change.
Spring is one of the four seasons of temperate zones. Astronomically, it begins with the spring equinox (around March 21 in the Northern Hemisphere, and September 23 in the Southern Hemisphere), and ends with the summer solstice (around June 21 in the Northern Hemisphere and December 21 in the Southern Hemisphere). In meteorology, it is by convention instead counted as the whole months of March, April, and May in the Northern Hemisphere and September, October, and November in the Southern Hemisphere. However, in the Irish Calendar it is counted as the whole months of February, March and April.
Severe weather most often occurs during the spring, when warm air begins to invade from lower latitudes while cold air is still pushing from the polar regions. Flooding is also most common in and near mountainous areas during this time of year due to snow melt, many times accelerated by warm rains. In the united States, Tornado Alley is most active by far this time of year, especially since the Rocky Mountains prevent the surging hot and cold air masses from spreading westward and instead force them directly at each other. Besides tornadoes, super cell thunderstorms can also produce dangerously large hail and very high winds, for which a severe thunderstorm warning or even tornado warning is usually issued. Often, spring storms trigger dozens of warnings, one right after the other, often simultaneously along a line hundreds of miles or kilometers long. Even more so than winter, the jet streams play an important role in severe weather in the springtime.
Some of the worst blizzards have occurred in the spring, including the Great Blizzard of 1993, which brought hurricane conditions and then light snow to northern Florida on March 13, and deposited up to five feet of snow in parts of the Appalachian Mountains. A massive springtime "upslope" winter storm in 2003 brought up to eleven feet of snow to parts of Colorado and three feet to Denver, which gets more snow in March and April (and again in October and November) than during the entire winter (December to February).
Hurricane season also begins in late spring, on May 15 in the northeastern Pacific and June 1 in the northern Atlantic. Prior to these dates, hurricanes are almost unheard of and even tropical storms are exceedingly rare, one of the earliest ever being Tropical Storm Ana in mid-April 2003.