A look back: March 1993 blizzard, February 2010 snowstorm

PITTSBURGH — There have been just four occasions on record that have produced more than 20 inches of snow during a single storm. In recent history, there have been just two storms producing more than 20 inches of snow: March 1993 and February 2010.

Here's a breakdown of the largest snow storms on record:

1. 27.4 inches – Nov. 24-26, 1950. Thanksgiving 1950. 2. 25.9 inches – Dec. 16-18, 1890. 3. 25.3 inches - March 12-14, 1993. 4. 21.1 inches – Feb. 5-6, 2010.

Let's go back to 1993. On Friday, March 12 snow began to fall late that night. The next day we saw the greatest one-day snowfall at 23.6 inches. The old record was 22 inches set on Dec. 17, 1890. The total snow for the storm: 25.3 inches

The St. Patrick's Day parade continued in downtown Pittsburgh on Saturday, March 13, as the storm really kicked in. Snowfall rates were 2 to 3 inches per hour at times.

The storm produced high wind, blowing and drifting snow with wind chill temperatures dangerously below zero.

People were urged to stay indoors. The turnpike, interstate highways and most roads were shutdown, impassable. Everything came to a screeching halt

The 1993 storm of the century marked a milestone when forecast models saw the threat of a significant snowstorm, and for the first time, meteorologists were able to predict accurately a storm's severity five days in advance.

Luckily in 1993 the snow didn't last. Long, mild days in March melted snow rapidly.

 Photos from this past year's significant winter storms:

• Feb 3, 2013 snow storm photos
• Jan. 25, 2013 snow storm photos
• Dec. 26, 2012 snow storm photos

Now the other big snowstorm many of you remember happened Feb. 5 and 6 of 2010. The storm total: 21.1 inches. The snowfall averaged nearly an inch an hour.

The most intense periods were from 7 p.m. to midnight Friday when 7 inches fell. From 3 a.m. to 6 a.m. Saturday another 5.3 inches fell. It was worse in higher elevations. Somerset County saw 30 inches of snow.

The 2010 storm was unlike the blizzard of 1993, because the snow was heavy and wet, which caused more damage to trees and power lines. Thousands of people in southwestern Pennsylvania ended up without power. For many, it would be a week or more after the storm before power would be restored.

In 2010, we had a snow storm. In 1993 we had a blizzard.

The difference between a blizzard and a snowstorm is the strength of the wind. A snowstorm must have winds in excess of 35 mph with blowing or drifting snow, which reduces visibility to a quarter mile or less, and the wind must last for a prolonged period of time, typically three hours or more.

WPXI