Spring will arrive (hopefully) in just a few weeks. That arrival brings with it thoughts about the returning birds, the first sweet scents of early spring flowers and new grass, and the first rumbles of thunder. Even though there may still be significant piles of snow left on the ground, it is very likely that thunderstorms will occur in the longer daily hours of sunlight and as the air continues to warm.
So here are some interesting facts about T-storms that you may not have recalled. Please enjoy them and remember to always get a thorough weather briefing before you take off.
Did you know…
• Most thunderstorms move in the direction of the wind flow, through the layer of the Troposphere, however, vertical wind shear can cause some deviation in the storm track at a right angle to the wind shear direction.
• The average T-storm has a diameter of up to 15 miles and lives for approximately 30 minutes.
• Approximately 5×108 kg of water vapor is lifted into the atmosphere during a typical T-storm.
• Vigorous cells that develop on the upwind side of a line of storms (most often the southwest or west side) are called back-building thunderstorms.
• Slow moving T-storms that are producing heavy amounts of liquid precipitation can create flash flood conditions especially in urban areas. This is due to the amount of paved over land, and lack of bodies of water and open land that can absorb the heavy rain.
• Thunderstorms are most prevalent in the mid-latitudes, but though rare, can also occur in Polar Regions.
• The Midwest and southern states are home to some of the most powerful T-storms in the U.S.
• About half of the Great Plains’ warm season rainfall is brought about by Mesoscale Convective Systems.
• The temperature of an average bolt of lightning can exceed 52,000 degrees Fahrenheit. Ironically, lightning is the direct result of the collision of super-cooled droplets of water with ice crystals at or near the freezing level.
• About 10 percent of thunderstorms are classified as severe – one that produces hail at least three-quarters of an inch in diameter, has winds of 58 miles per hour or higher, or produces a tornado.
• Types of T-storms in Minnesota to watch for: Strong squall line storms with high straight line winds and just ahead of cold fronts in late March, April, May, June, July, August, September and sometimes October. The peak for these storms is May through July.
• Supercell T-storms (storms that produce large hail and tornadoes ) in late March, April, May, June, July, August, September, October and November. The peak is late April through May and into early July. June is the most likely month for supercells with tornadoes. Large hail is a more significant risk in August and September due to cooling.
• T-storms with cold fronts are usually in the day along a line, and these storms often decrease in intensity after sunset as daytime temperatures cool.
• T-storms with warm fronts are usually more active at night, especially with a low-level jetstream at 5,000 feet or higher from the southwest with winds above 35 mph.
• Stationary fronts can produce potent thunderstorms.
EDITOR’S NOTE: Special thanks to Jonathan Yuhas, meteorologist, for his generous input on this article. Besides being a meteorologist on KARE 11 TV in the Twin Cities, Mr. Yuhas teaches Aviation Meteorology at Thunderbird Aviation in Eden Prairie, Minnesota. He is also the driving force for the Minneapolis-based company FlashWarn, a severe weather consulting company. FlashWarn educates and enhances schools and businesses on severe weather training and planning. For more information about FlashWarn, contact: jkyuhas@comcast.net.
This is not an endorsement of any company, organization or person, and is presented here solely for the information, education, understanding, and convenience of the reader.
