Tag Archives: storms

Widest Tornado on Record Strikes El Reno, Oklahoma

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A massive twister struck the town of El Reno, OK on Friday.  Measuring 2.6 miles across, it was the widest tornado ever recorded.

According the National Weather Service, the winds of this violent storm reached as high as 295 mph.  On the ground for forty minutes, it traveled more than sixteen miles. This powerful twister and the flooding rains associated with it claimed the lives of nineteen people, including three storm chasers.

Initially classified as an EF-3, the NWS upgraded this storm to an EF-5 – the highest ranking on the Enhanced Fujita Scale – after evaluating the damage. This was the second EF-5 tornado to strike Oklahoma in less than two weeks.  The other leveled the nearby city of Moore.

Since 1950, according to NOAA’s Storm Prediction Center, sixty EF-5/F-5 tornadoes have struck the United States.  Eight of these touched down in Oklahoma.

2013 Atlantic Hurricane Season Forecast

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Hurricane season begins tomorrow and it is expected to be busy.

Tropical cyclones, known as hurricanes in the United States, develop around the globe at different times of the year. In this country, we are most affected by the Atlantic hurricane season, which runs from June 1 through November 30.  Peak activity, however, is usually from August to October when sea-surface temperatures are warmer.

Last year was an extremely active season with nineteen named storms – the third consecutive year with that number.  Four of these made landfall in the US: Beryl, Debby, Isaac, and Sandy.

This year, NOAA is predicting another above average season. Some of the main climate factors of this energetic forecast include warmer than average Atlantic ocean temperatures – which fuel hurricanes – and a currently neutral El Nino-Southern Oscillation pattern in the Pacific.  When the El Nino aspect of this oceanic-atmospheric phenomenon is present, it produces upper level winds that can limit the development of Atlantic cyclones.  The neutral phase of this pattern, however, allows for a more favorable environment for storms to develop.

Atl_Hur_2013Chart Data: NOAA

 

Devastating Tornado in Oklahoma

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Barreling through the Oklahoma City area on Monday afternoon, a powerful tornado leveled the suburb of Moore, OK.  It claimed the lives of twenty-four people and injured hundreds of others.

The National Weather Service has rated this deadly twister as an EF-5.  That is the highest ranking on the Enhanced Fujita Scale.  On the ground for forty minutes, with winds in excess of 200 mph, this powerful storm cut a path of destruction seventeen miles long and more than a mile wide.

Located in the heart of tornado alley, this community is no stranger to severe weather events.  Moore was in the path of the infamous tornado of May 3, 1999 that set the record for the fastest wind speed ever recorded, 318 mph.

As it has in the past, this town is planning to rebuild.  The price of which, according to current insurance estimates, is expected to exceed two billion dollars.

A field of debris from Monday's EF-5 Tornado in Moore, OK.

A field of debris from Monday’s EF-5 Tornado in Moore, OK.

Image Credit: Oklahoma County Sheriff’s Office/ABC

Deadly Tornado Outbreak in Texas

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A swarm of tornadoes barreled across northeastern Texas on Wednesday evening.  These powerful storms caused widespread damage and claimed the lives of at least six people.

The National Weather Service, in its preliminary assessment, reported that sixteen twisters touched down near the Dallas-Fort Worth Metroplex, one of the largest metropolitan areas in this country.  The strongest storm in this outbreak was rated an EF-4, the second highest ranking on Enhanced Fujita Scale. With winds ranging from 166 to 200 mph, it devastated the town of Granbury, TX. Another hard hit area was Cleburne, TX, where an EF-3 storm is reported to have cut a path one-mile wide through part of the city.

Tornadoes, nature’s most violent storms, are generated by severe thunderstorm activity.  That said, not all thunderstorms produce twisters.  They need something to set the lower atmosphere into a twisting motion.  In this case, that was warm, humid air moving north from the Gulf of Mexico that collided with hot, dry air blowing in from the west.

Texas Tornado

Texas Tornado

Image Credit: WHNT

A Day of Downpours in NYC

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Torrential downpours drenched New York City yesterday.  In fact, the Big Apple received nearly a month’s worth of rain in just one day.

According to the National Weather Service, 3.02 inches of rain fell in Central Park.  Not only is that a new daily record, it is more than double the amount of rainfall the city received during the entire month of April.

After a stretch of twenty-five days with hardly any significant precipitation, yesterday’s rain was very beneficial for the area.  The rate at which it came down, however, caused a number of localized flooding problems.

Sandy Highlights the Dangers of Rising Sea Levels

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Six months ago today, Super-storm Sandy devastated a large section of the northeastern United States.  The flooding caused by its record storm surge was a heart-wrenching example of the dangers posed by rising sea levels.

Storm surge is the rise in sea height that occurs during an intense storm like a hurricane or nor’easter. Its baseline is local sea level. So, as sea levels rise, storm surges are able to reach further inland.  This is a serious problem for coastal communities around the world.

According to climate scientists, the average global sea level has risen about eight inches since 1880.  This may not sound like a lot, but it is a significant amount when you consider it is spread out across all of the world’s oceans.  That said, sea levels are not rising evenly across the planet.  Recent studies have found that certain areas, such as the East Coast of the US, are experiencing faster rates of sea level rise than others.  New York Harbor, for example, has seen its water level increase by more than a foot in the past century.

Sea level rise has two main drivers. They are thermal expansion – a process in which water expands as it warms – and the melting of massive amounts of land based ice, such as glaciers and ice sheets.  Both are the result of rising global temperatures.

In the future, sea levels are expected to continue rising as our atmosphere warms. Estimates of how much vary from four inches to two feet above current levels by 2050. This wide range reflects uncertainty in the amount of future greenhouse gas emissions, subsequent warming, and rate of ice melt.  What is certain, however, is that the frequency and magnitude of storm surge flooding will increase as sea levels rise.

Sandy is Retired from List of Hurricane Names

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There will never be another Hurricane Sandy – at least not in name.  The World Meteorological Organization has announced that it is officially retiring the name from its list of Atlantic cyclones.

The WMO is responsible for naming tropical storms and hurricanes around the world.  It maintains a set of six rotating lists for each hurricane-prone region. After a six-year cycle, names are re-used.  Names are only retired when a storm was particularly noteworthy – causing a large number of fatalities or an extraordinary amount of damage. In terms of Sandy, the late October storm claimed the lives of 72 people and caused more than $50 billion worth of damage in the United States alone.

Sandy is the 77th name to be retired from the Atlantic list since the current naming system began in 1953. It will be replaced with Sara beginning in 2018, when last year’s list is recycled.  Some other retired Atlantic Basin names include: Andrew, Katrina, and Irene.

NWS Changes Hurricane Warning Policy

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The National Hurricane Center, in the aftermath of Super-storm Sandy, drew heavy criticism for not issuing a warning in the northeastern United States ahead of the storm.  In response, the NHC announced yesterday that it is changing its policy for how post tropical storm warnings are delivered to the public.

According to the National Weather Service, Sandy was a category-1 hurricane that merged with a cold front and transitioned to a post tropical storm just prior to coming ashore.  Simply put, this means the storm’s energy source changed.  Nonetheless, it still delivered hurricane-strength winds and a devastating storm surge.  While the NWS explanation was technically correct, the change in nomenclature proved to be a source of confusion and led many people to under estimate the threat posed by the historic storm.

Until now, the NHC was only allowed to publish warnings for narrowly defined hurricanes and tropical storms.  With the implementation of the new policies, however, the hurricane center will be able to keep warnings and advisories in place for storms that threaten people and property, even if they lose their tropical characteristics. The new procedures go into effect on June 1st, the official start of the 2013 Atlantic Hurricane Season. Hopefully, this new approach will avoid any misperceptions in future.

Event: The Science Behind Sandy

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On Thursday, April 4th, Columbia University’s Lamont-Doherty Earth Observatory will be hosting a public lecture, “The Science Behind Sandy”.

Adam Sobel, an atmospheric scientist and professor at Columbia, is expected to address many of the meteorological questions raised by the historic storm.  Some of these include: What kind of storm was Sandy?  How rare was it?  Can we expect more storms like it in the future?

In light of the catastrophic damage that Super-storm Sandy caused in the New York City area, and the current debates on how to re-build, this talk should be very informative.  For more details, please visit the LDEO website.

 

A Taste of Spring in NYC

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A winter storm lingered over much of the northeast late last week.  In New York City, it deposited 4 inches of dense, wet snow in Central Park.  In the storm’s wake, however, Spring-like conditions swept across the area.

The city reached a high temperature of 55°F on Saturday and saw all of the recent snowfall melt away.  Only two days earlier, we had a high of 38°F.  Our normal high for this time of year is 47°F.

As pleasant as this spring preview has been for many winter-weary New Yorkers, forecasters expect to see cool conditions return by the end of the week.