Scary 'Twin' Tornadoes Rip Through Nebraska
May 15, 2012, Ormond Beach, Florida. Photo by
Oct. 2, 2012 --
NASA's Global Precipitation Measurement satellite mission is working to understanding extreme weather with photos of rain and snow worldwide every three hours. But how do these storms look on the ground? NASA's GPM extreme weather photo contest highlights the beauty and ferocity seen first hand from storm-chasers before they duck for cover. Here are NASA's top five picks from over 100 submissions. This photo by Jason Weingart, a photography student at the University of Central Florida, shows a Volusia County lifeguard signaling to surfers at Ormond Beach, Fla., that it is time to exit the water. "The storm actually pushed back on shore as it moved south, and then became strong enough for tornado warnings on three separate occasions. I saw a large wall cloud, another spectacular shelf cloud, and some very tight rotation in the couple hours I stuck with the storm after I left the beach in Ormond," wrote Weingart. NASA Fun Fact: "A shelf cloud is a type of arcus cloud with a wedge shape. It is a low level, horizontal cloud formation usually associated with the leading edge of thunderstorms. The leading (outer) part of the shelf cloud appears smooth due to rising cloud motions, while the underside often appears jagged and wind-torn."
May 22, 2011 Dane County, Wisconsin. Photo by
Atmospheric scientist Grant Petty of the University of Wisconsin - Madison, was with a photography club on a farm in Dane County when he saw this thunderstorm building several miles to the east. "The storm cell dropped 1-3/4 inch hail near Sun Prairie. Fall streaks barely visible under the right side of the anvil may in fact be the falling hail,” he said.
PHOTOS: Sun Dogs, Halos, and Double Rainbows
July 5, 2011 Maricopa, Arizona. Photo by Megg
“This photo was taken in a wash that runs through my neighborhood in Maricopa, AZ. The wash runs north/south through the neighborhood and the haboob (type of intense dust storm) was rolling in from the east," reported photographer Meggan Wood. "I saw the wall of dust coming and quickly drove to the wash to get a good wide-open view of the height of the dust looming over the houses. I barely had time to get back to my car before it hit and I was engulfed! The darkness was surprising but it only lasted about 10-15 minutes before it thinned out enough to where I could drive back home, only about 2 minutes away. This was the giant haboob that made national news when it rolled through and entirely covered all of Phoenix and some surrounding cities. Maricopa is about a half-hour drive south of the Phoenix Sky Harbor airport."
PHOTOS: After the Dust Settles
September 1, 2012 Arlington, Virginia, lookin
Journalist Brian Allen with the Voice of America was at home in Arlington, Va., when this storm rolled over Washington. "The storm that blew through started off with an incredible amount of lightning and then dumped a significant amount of rain in a short amount of time -- on the other side of the river. DC got drenched and Arlington didn't see a drop,” he reported.
NEWS: Lightning Still Largely a Mystery
May 30, 2012 Kechi, Kansas. Photo by Brian Jo
Writer and photographer Brian Johnson is a also an avid storm-chaser for several Kansas radio stations. “As a large squall line moved through the area. The National Weather Service had warned about a large scale Derecho forming and moving through," he wrote. "This spawned a couple brief severe thunderstorms that dumped hail on rush hour traffic before the main line moved in. As the bigger storm moved into the Wichita area, reports were coming in of 70 mph winds and hail. There is an open farm field roughly two miles from my house that I shot lightning on the previous night. I sat there for about 20 minutes before this large squall line pushed through the clouds. I was hit with a pretty good gust front as it got closer, but as the winds increased, I decided to get to shelter. This photo was one of the last ones I took." Read more about Johnson's storm-chasing adventure here:
NEWS: Photos Catch Monster Storm's Approach: Big Pics
PHOTOS: Twilight: 15 Reasons to Watch
Two people were killed and 16 were critically injured in northeast Nebraska on June 16 in a freakish weather catastrophe, when two separate tornadoes touched down about a mile apart.
According to NBC News, the first tornado tore down power lines and leveled a daycare center, and rescue workers were still pulling people out of the wreckage when they learned that a second tornado was hurtling toward them. That twister proceeded to level much of Pilger, a town of 350 about 75 miles west of Omaha.
According to NOAA’s tornado primer, tornadoes generally have multiple vortexes, though they’re not always visible unless the storm is really intense. But a true twin -- that is, a separate tornado that forms alongside another, which technically is called a satellite tornado -- is relatively rare. Exactly why satellites form is unclear, but they usually appear near a much larger tornado and then orbit it, according to NOAA.
As AccuWeather meteorologist Alex Sosnowski explains, thunderstorms form because of very warm, very moist air that creates instability in the atmosphere. As the air rises, it cools and forms towering clouds, and shifting winds with height, or wind shear, cause the formation to spin in the air, a phenomenon which is called helicity.
While several severe thunderstorms can coexist in one area, the strongest and most severe thunderstorms -- the ones capable of producing separate twin funnels -- tend to be isolated, so that they don’t have other storms competing for the atmosphere’s energy.
Having two separate cyclones strike in close order compounds the damage and possible loss of life. There are a bunch of historical accounts of horrific carnage inflicted by twin tornadoes, such as the pair that struck Elkart and Dunlap, Ind., on Palm Sunday in 1965.
Photo: A violent wedge tornado ripped through a small community in Nebraska Monday (June 16) dropping three tornadoes at once. Credit: Daniel Shaw/Demotix/Corbis