28 October 2011
Posted in WFTV Severe Weather Center 9

While most of us shudder at the thought of hurricane season, there is one colorful ocean dweller that actually benefits from these tropical cyclones. According to Derek Manzello, who studies the life of coral reefs at the Atlantic Oceanographic and Meteorological Laboratory in Miami, Florida, hurricanes can bring up cooler waters from the depths of the ocean and bring aid to coral reefs that are in danger of bleaching. This act of circulating cool water is known as upwelling.

Corals have tiny organisms called Coral Polyps that contain photosynthetic algae called zooxanthellae, which provide the coral with food and bright coloring. Coral bleaching takes place when zooxanthellae leave the coral, due to increased water temperatures or other stress factors. Because the coral has no way of feeding itself, it eventually dies. However with the help of hurricanes, water temperatures are brought down and the coral is able to recover in about 1 month.

In 2005, coral reefs in the Caribbean suffered the most damage and bleaching due to very high water temperatures. However, they recovered much faster than nearby reefs. The winds from all of the tropical cyclones that passed within 435 miles of the Florida Reef Tract east of the Florida Keys lowered the surrounding sea surface temperatures by as much as 5.8 degrees F.

Occurences like these are good reminders that, even under the most terrifying circumstances, Mother Nature has a way of finding something good.

11 July 2011
Posted in WFTV Severe Weather Center 9

El Nino and La Nina are the two most powerful weather phenomena on the planet and are known to alter the climate across more than half the planet! El Nino is the warming of water in the Pacific Ocean, determined by a comparison of average water temperatures over several years. If the ocean between the coasts of South America-Peru, Ecuador, Columbia-and the middle of the ocean toward the Date Line is warmer by 2-10 degrees F, we know that an El Nino is here. La Nina, officially called ENSO, is the cooling of water in the Pacific Ocean. El Nino and La Nina may alternate between every other year and every three years, so that the time from one El Nino to the next tends to be every three to seven years.

The tremendous phenomena of El Nino, known for its warming effect on the water in the Pacific Ocean is likely caused by underwater volcanic activity. El Nino weather can include rain and flooding along the Pacific coast, tornadoes and thunderstorms in the southern U.S., and fewer than normal hurricanes in the Atlantic. The warm waters of El Nino are also known to disrupt the food chain of fish, birds and sea mammals. During an El Nino, an increased dryness can occur in areas typically saturated with rainfall between November and March in the western Pacific over Indonesia and northern Australia. On the flip side, other areas such as Peru and Ecuador see an increase in rainfall. In fact, the El Nino was discovered in Peru by fishermen who noticed that every three to seven years, there was an increase in rainfall.

Satellite Image of El Nino

La Nina happens about half as often as El Nino. During a La Nina, winter temperatures in the U.S. are warmer than normal in the Southeast and cooler than normal in the Northwest. La Nina, known for its cooling effect on the water in the Pacific Ocean, can include weather like snow and rain on the west coast, unusually cold weather in Alaska, unusually warm weather in the rest of the U.S., drought in the southwest, and a higher than normal number of hurricanes in the Atlantic.

Satellite Image of La Nina

The reason there are fewer hurricanes during El Nino, despite warmer waters, can be explained by the jet stream, or a long, narrow, wandering current of high speed winds blowing from a generally westerly direction several miles above the Earth’s surface. El Nino tends to suppress the formation of hurricanes by steering the subtropical jet stream into the hurricane’s path and effectively cutting off the tops of the hurricanes with its strong winds, preventing them from growing any bigger. During a La Nina, on the other hand, the jet stream works in the advantage of a forming hurricane, allowing them to grow with ease and great intensity.

07 July 2011
Posted in WFTV Severe Weather Center 9

Nothing describes mother natures’ persistence better than the way Barbara Kingsolver puts it in her popular novel, Poisonwood Bible, “this forest eats itself and forever lives.” The fierce forces of nature can be intense and enduringly unpredictable. A dust storm is no different.

Dust storms are not just desert phenomena. They can occur in any dry area where loose dirt is exposed to the elements and can easily be picked up. Heavier grains of sand generally fall back down to the ground after a few hours, but smaller particles can stay in the air for weeks at a time and can be blown thousands of miles.

With the recent wildfire activity out west, there are a lot of small smoke and dust particles already collected in the air, drifting and swirling with the wind currents. If the winds become strong enough, these particles form a wall-like structure and can suddenly loom over hundreds of miles and rise above 10,000 feet.

Usually these storms last only a few minutes, but that is long enough to hinder visibility on the highway, hinder air traffic and threaten the health of those with asthma and other respiratory diseases.

It is estimated that Australia spends an average of $20 million a year on medical bills because of asthma and other respiratory diseases exacerbated by the fierce dust storms.

During the 1960s there were eight dust storms that caused some serious damage; 13 more in the 1970s; 14 in the 80s and more than 20 in the 1990s. Although some storms are not as severe as others, even a mild dust storm is not a pleasant experience to walk through. It is recommended that you seek shelter when you see the wall of dust forming.

This week, a dust storm descended on Phoenix, Arizona, delaying flights and significantly reducing visibility.  Many longtime residents say it was the biggest they had ever seen.

This storm is only the first hint of the upcoming monsoon season, which typically starts in mid-June and lasts until the end of September. Below is a link to a video of the wall of dust that hit Phoenix on Tuesday, July 5.

29 June 2011
Posted in WFTV Severe Weather Center 9

Although the wildfires in Arizona have been almost completely contained at the moment, the Las Conchas wildfire in New Mexico rages on because of the red flag weather conditions (high temperature, high wind and low humidity.) As of June 27, 2011, 8:00 a.m., New Mexico time, the wildfire is approximately 1 mile southwest of the boundary of Los Alamos National Laboratory, famed nuclear research facility. Because of a similar incident that occurred 11 years ago, the Lab is prepared and has already accounted for all radioactive materials and has secured the site.

Currently, firefighters are using fires to fight fires. The hope is that if firefighters use prescribed burns to eliminate fuels in the path of the fire. Then the wildfire will have nothing left to feed on by the time it reaches the points where the prescribed fires were set and eliminated. For up to date information on the New Mexico fires visit this website.