The Weather Guys

A GOES East satellite image provided by the National Oceanic and Atmospheric Administration (NOAA) on Thursday shows Hurrican Matthew — the first Category 5 hurricane in the Atlantic basin since Hurricane Felix in 2007 — in the Caribbean Sea about 190 miles northeast of Curacao. The category of a hurricane is determined by reconnaissance aircraft flights into the storm along with analysis of satellite images. The satellite approach is led by scientists at the UW-Madison as part of the Cooperative Institute for Meteorological Satellite Studies, or CIMSS (Photo credit: NOAA)

An obvious hurricane threat is its powerful wind, which can blow in a single spot for many hours.

Wind damage is such a hallmark of hurricanes that hurricane intensities are classified by meteorologists using the Saffir–Simpson scale, which rates hurricanes on a scale of 1 to 5 based on the damage their winds would cause upon landfall.

Major hurricanes are those classified as Category 3 and higher on this scale. Category 3 hurricanes have a one-minute sustained wind between 111 mph and 130 mph.

The one-minute sustained winds in a Category 5 hurricane are greater than 155 mph.

The category of a hurricane is determined by reconnaissance aircraft flights into the storm along with analysis of satellite images.

The satellite approach is led by scientists at UW-Madison as part of the Cooperative Institute for Meteorological Satellite Studies, or CIMSS.

This collaboration between the university and the National Oceanic and Atmospheric Administration (NOAA) supports research on weather satellites.

Hurricane Matthew intensified in the Atlantic Ocean this past weekend and will threaten the U.S. mainland this week.

A reconnaissance plane recently measured wind speeds in this storm and those measurements along with the CIMSS analysis led NOAA to list Matthew as a Category 5 storm.

This is the first Category 5 hurricane in the Atlantic basin since Hurricane Felix in 2007.

Fortunately, most hurricanes do not produce the extreme winds linked with the highest category on the Saffir–Simpson scale, but any category storm can do major damage when it hits land.

Flooding from hurricanes causes major damage to shorelines and buildings. The winds in a hurricane push ocean water in front of them. The stronger the wind, the more water is “piled up.”

As the hurricane nears shore, the wind pushes this water inland. This process of wind-induced seawater flooding is called storm surge.

Historically, the storm surge has caused as much as 90 percent of all hurricane-related deaths.

Flooding from rain can also be dangerous.

Hurricane Floyd made landfall in 1999 as a Category 2 storm. Flooding that ensued along the U.S. East Coast accounted for most of the death toll of 57.

Water from Roanoke Sound pounds the Virginia Dare Trail in Manteo, NC, Saturday, as Tropical Storm Hermine passes the Outer Banks. Hermine lost hurricane strength over land but intensified along the Atlantic Coast. (Photo credit: Tom Copeland, Associated Press)

On Friday Hurricane Hermine made landfall in Florida, making it the first to make landfall in the state in more than a decade.

Hermine, which weakened to a tropical storm shortly after landfall as is commonly the case with weak hurricanes, was poised to redevelop and pose a threat to the Mid-Atlantic states and possibly southern New England into the middle of the week.

Eighty-one years ago, nearly to the day, the famous Labor Day Hurricane of 1935 struck Florida with greater intensity than any other landfalling hurricane in the country’s history.

While Hermine had sustained winds of about 75 mph and dropped nearly 17 inches of rain in the Tampa/St. Petersburg area, the Labor Day Hurricane made landfall with sustained winds near 185 mph.

Both storms developed within days of Sept. 12, the date of the average peak frequency for such storms in the Atlantic Basin. Though the number of tropical cyclones in an average year numbers in the low teens, these storms are deserving of attention because they can wreak enormous damage to life and property.

They also play a substantial role in ventilating the tropical ocean and mixing heat from the tropics, where an annual surplus accumulates, to the high latitudes where an annual deficit stands in need of remedy.

It may seem surprising given our location in the middle of the North American continent, but hurricane research, employing both satellite observations and theoretical advances, at UW-Madison has led the way toward improved understanding and forecasting of these powerful storms.