Stories tagged thunderstorms


A number of severe thunderstorms have swept through the SE US recently. Some storms generated tornadoes that were truly devastating. The news channels have many photos of the ground destruction. We can see the path of the storms in satellite images. Here is a link to one of those images.

A comparison of 250-meter resolution image from a NASA MODIS instrument at 0.65 µm and 0.87 µm visible channel images centered on Tuscaloosa, Alabama on 28 April 2011 showed signatures of a few of the larger and longer tornado damage paths from the historic tornado outbreak (SPC storm reports) that occurred on 27 April 2011. The yellow arrows point to some of the paths.

Here is a link to an animation between the two channelsMODIS Image of Tornado Paths on 28 April 2011: NASA Satellite image see tornado path
MODIS Image of Tornado Paths on 28 April 2011: NASA Satellite image see tornado pathCourtesy CIMSS UW-Madison

It's Friday, so it's time for a new Science Friday video. Science Friday
Science Friday
Courtesy Science Friday
"Lightning is one of the biggest unsolved mysteries of the atmospheric sciences, researchers say. Scientists at the International Center for Lightning Research and Testing in Florida are inducing lightning to strike so they can understand it better. Though summer doesn't begin officially for a few weeks, one of the signature marks of summer may already be in the air near you -- the evening thunderstorm. Thousands of lightning strikes occur on the planet every minute, but the summer heat and humidity help to ramp up the number of lightning-producing thunderstorms. We'll talk about the science of lightning."
Learn more.

A felled tree in Central Park
A felled tree in Central ParkCourtesy zoolien
I don’t live in New York, and have only been there a couple of times. But the last time I was there I was able to spend a few minutes in wonderful Central Park, so this article caught my eye.

According to officials at the Department of Parks and Recreation and the Central Park Conservancy (who manage the park), over 100 trees were toppled in what they called the most severe destruction the park has seen in at least 30 years.

Check out these flickr images of the damage. Do you live in New York and/or have you seen the damage? Tell us about it by commenting below!

Folks in the Twin Cities saw 8" of snow on Wednesday 2/25, much of it falling in short bursts. People on the Eastern Seaboard saw some similar action earlier this week. Much of the accumulation was caused by a rare phenomenon called "thundersnow."

"According to Patrick Market, an associate professor of atmospheric science at the University of Missouri, a 30-year study of snowfall found that when lightning is observed during a snowstorm, there is an 86 percent chance that at least six inches (15 centimeters) of snow will fall within 70 miles (113 kilometers) of the flash. Researchers are trying to determine the combo of atmospheric conditions required to create thundersnow to help them better predict heavy snowfall—which they define as at least eight inches (20 centimeters) falling at a rate of three to four inches (7.5 to 10 centimeters) per hour—and issue warnings about hazardous weather before it hits, giving people time to prepare, take cover and get off the road.


Hail, hail this piece of hail: This is the world-record hailstone that fell in Aurora, Nebraska, in 2003. It has a diameter of seven inches and circumfrence of nearly 19 inches.
Hail, hail this piece of hail: This is the world-record hailstone that fell in Aurora, Nebraska, in 2003. It has a diameter of seven inches and circumfrence of nearly 19 inches.Courtesy NOAA
In the Twin Cities area, we’ve had some pretty impressive hail storms lately, at least if you’re measuring by frequency and intensity. Today’s Star Tribune has a nice round up on our surge in hail activities.

So what is hail any way, besides the sound of green to auto glass replacement and body shop companies?

Hail is formed when storm clouds supercool water droplets into frozen masses around particles of dust. The formation of thunderstorms is the ideal circumstance for creating hail. Updrafts in the storm’s formation blow the hail up into the thunderhead for a little while. Then the hail descends in the cloud, collects more moisture and becomes a bigger piece of ice when another updraft blasts it back up into the thunderhead. When those updrafts subside or the ice gets too big and heavy, the hail comes pelting back down to Earth on us, our vegetation and cars.

In the U.S., “Hail Alley” is located there Colorado, Nebraska and Wyoming converge. Worldwide, deadly hail storms have been recorded in India and China.

Before you start to think our recent hail storms here in the Twin Cities have been impressive, consider these storms:

• Around the 9th century, several hundred pilgrims were killed by a massive hailstorm in Roopkund, Uttarakhand, India.

• July 11, 1990, in Denver, Colorado, softball-sized hail destroyed roofs and cars, causing $625 million in total damage.

• April 14, 1999, in Sydney, New South Wales, Australia, $1.5 billion was done spread across 20,000 properties and 40,000 vehicles. In addition, more than 25 aircraft were damaged at Sydney Airport.

• July 19, 2002, Henan Province, China, resulted in 25 dead and hundreds injured.

• June 22, 2003, saw the largest hailstone on record fall in Aurora, Nebraska, It has a 7-inch diameter and a circumference of 18.75 inches.

Itching to learn more about hail? Here's a link to the Wikipedia page of all things hail.

UK doctors have warned mobile phone users of the risks associated with mobile phone usage during thunderstorms. Metal found in mobile phones is able to send lightening currents directly into your body-possibly creating lots of damage!