Atlantic Hurricane Season Ends Quietly
The 2013 Atlantic hurricane season officially ended Saturday and it was the quietest since 1982.
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
The 2013 Atlantic hurricane season officially ended on Saturday as the quietest since 1982 and the sixth least active since 1950, the US National Oceanographic and Atmospheric Administration said.
Thirteen tropical storms formed since early June in the Atlantic but only two, Ingrid and Humberto, reached hurricane strength. While the number of named storms topped the historical average of 12, the number of hurricanes was well below the historic average of six medium-strength category one or two storms and three major category three storms and above.
Category three hurricanes have wind speeds of at least 110 miles (178 kilometers) per hour, while a category four storm can pack winds of 130 miles (210 kilometers) per hour or more. The most damaging are category five storms with winds of at least 155 miles (250 kilometers) per hour.
NOAA had predicted in May that 2013 would be more active than usual, with 13 to 20 tropical storms, and three to six hurricanes.
"This unexpectedly low activity is linked to an unpredictable atmospheric pattern that prevented the growth of storms by producing exceptionally dry, sinking air and strong vertical wind shear in much of the main hurricane formation region, which spans the tropical Atlantic Ocean and Caribbean Sea," said Gerry Bell, NOAA's lead hurricane forecaster.
"Also detrimental to some tropical cyclones this year were several strong outbreaks of dry and stable air that originated over Africa."
A study published in June in the British journal Nature Geoscience, found that a drop in the frequency of tropical storms in the north Atlantic during the 20th century may have resulted from human activity through the production of aerosols, tiny chemical particles suspended in the atmosphere. Aerosols may affect the formation of clouds and more importantly act as a screen to reduce the ocean's surface temperatures, thereby reducing the heat that fuels tropical storms.
The work of Nick Dunstone of Britain's Met Office showed that storms and hurricanes were less frequent in the north Atlantic during periods of high concentration of aerosols over the region.
Conversely, the study found that measures since the 1980s to tackle pollution and improve air quality reduced levels of aerosols and in turn ramped up hurricane activity. And they anticipate that Earth-warming greenhouse gases will exert more influence on the frequency of tropical storms than aerosols. Other studies have linked climate warming to an increase in intensity of tropical storms.
While the United States emerged largely unscathed from the hurricane season this year, Mexico was hit by five tropical storms and three hurricanes. Three of the storms originated in the Atlantic and the other five in the northeast Pacific, NOAA said.