Could climate change be behind Hurricane Florence?


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The National Hurricane Center shows the “cone of uncertainty” predicting where Hurricane Florence’s eye might travel.

Julia Poska| September 14th, 2018

North and South Carolina have both issued evacuation warnings in anticipation of a very destructive weekend. The eye of Hurricane Florence is made landfall this afternoon, though her rain bands touched land late Thursday.

As of Thursday morning, Florence’s strongest sustained winds of 105 mph put her in Category 2 classification for wind. As of Friday afternoon, she has downgraded to Category 1.  Forecasters say her storm surge, the swell of water pushed onshore by hurricane winds, will be a Category 4. The National Hurricane Center predicts floods over 9 feet above ground in some areas.

States as far inland as Indiana may receive the tail end of the hurricane, which will most likely have weakened to a less windy but still wet tropical storm or depression by then.

Experts debate whether climate change will increase the frequency and severity of tropical storms and hurricanes in coming years, and whether it already has. It is difficult to separate natural variability from human-induced effects when examining any specific storm, but many of the conditions needed to spawn hurricanes are certainly undergoing change.

To many experts, it seems to many that rising sea levels exacerbate storm surge, that rising sea surface temperatures could add more fuel to storms, and that a warmer, wetter atmosphere increases rainfall.  Just look to 2017’s especially devastating season for evidence that these storms are getting nastier.

Other experts say that climate change will increase wind shear, friction between upper and lower level winds moving in different directions, which could actually stop more hurricanes from forming. Only time will tell which factors

As climate change is variable over the Earth’s surface, models show both increase and decrease of all those different factors in different locations. While climate change will almost certainly impact hurricanes, only time will tell the nature of that impact.

 

On The Radio – September 2017 record-setting month for hurricanes


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Hurricane Maria churning over the Atlantic Ocean. (NASA)
Jenna Ladd | October 23, 2017

This week’s On The Radio segment discusses the unprecedented severity of hurricane activity in the Atlantic ocean this September. 

Transcript: September 2017 was a record-setting month for hurricane activity in the Atlantic Ocean.

This is the Iowa Environmental Focus.

It is common for September to be the most active month for hurricanes because low pressure systems often move across the Atlantic and meet the tropical waters of the Caribbean during that month, but September 2017 was a cut above the rest.

The beginning of September brought Hurricane Harvey, a category four storm which caused unprecedented damage to, Houston, the U.S.’s fourth largest city. Five additional hurricanes left paths of destruction across the Caribbean and Florida during September, with Irma and Maria both reaching category five status.

Last month, the overall intensity and duration of storms, known as “accumulated cyclone energy,” was 175 units, significantly higher than September 2014’s record of 155 units. While climate change has not been found to cause hurricanes, there is evidence to say that rising sea temperatures make them stronger.

For more information, visit Iowa-environmental-focus-dot-org. From the UI Center for Global and Regional Environmental Research, I’m Betsy Stone.