Hurricane season what is the saffir-simpson scale; how does it work gsa 2016 calendar


Robert Simpson had first-hand knowledge of hurricanes from an early age. In 1919, when he was 6, he and his family survived a massive hurricane that made landfall near Corpus Christi, Texas. The family had to swim down the streets of the town to safety as the waters rose to 8 feet above street level.

“The family had to swim — with me on my father’s back — three blocks in near hurricane force winds to safe shelter in the courthouse,” Simpson said. “A lot of what I saw frightened me, but also supplied a fascination that left me with a lifelong interest in hurricanes.”

After graduating from Southwestern University in Georgetown, Texas, and then earning a master’s degree at Emory University in Atlanta, he worked as a music teacher in Texas high schools because he could not find work as a physicist. Finally, in 1940, he was hired by the U.S. Weather Bureau as a meteorologist. Simpson worked all over the world for the Weather Bureau, with stints in New Orleans, Panama, Miami, Hawaii and Washington D.C.

In the 1950s, he lobbied officials at the Weather Bureau (the forerunner of the National Weather Service) to do more research into tropical systems and the effects they have on coastal areas. His arguments worked, and in 1955, he was appointed to lead the National Hurricane Research Project.

He headed up the project for four years then left to get a doctorate at the University of Chicago. In the 1960s, he was in charge of Project Stormfury, an experiment in which clouds were seeded with silver iodide in the hopes of diminishing hurricane intensity.

Saffir’s United Nations project work led him to creating a rating system for hurricanes that the U.N. could use to try to match buildings with their potential risks for damage. At the time, hurricanes were classified as either “minor” or “major” storms. In 1969, Saffir came up with a rating system that included five categories using wind speed, barometric pressure, likely flooding and storm surge as determining factors.

The system remained as it was developed until 2009 when the NHC eliminated storm surge, pressure and potential flooding from the factors that make up the categories. Those factors, the NHC explained, did not always match up with the damage that storms can inflict.

Another change was made in 2012 when the wind speed for a Category 4 storm was changed by 1 mph at both ends of the category. That was done because winds speeds are measured in 5-knot increments by the NHC, and the conversion to a miles-per-hour-measurement was incorrectly classifying storms as either Category 3 or Category 5.

The scale has five categories ranging from Category 1 – with winds from 74 mph to 95 mph to a Category 5 – with sustained winds in excess of 155 mph. The National Hurricane Center uses a one-minute averaging time to establish a measure of sustained winds. In other words, the highest winds speed maintained for a full minute would be the highest sustained wind speed for a storm.

Category 1: Maximum sustained winds are at 74-95 mph. Very dangerous winds will produce some damage: Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days.

Category 2: Maximum sustained winds are at 96-110 mph. Extremely dangerous winds will cause extensive damage: Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks.

Category 3: Maximum sustained winds are at 111-129 mph. Devastating damage will occur: Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.

Category 4: Maximum sustained winds are at 130-156 mph. Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.

Category 5: Maximum sustained winds are at 157 or higher. Catastrophic damage will occur: A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.

Before his death in 2014, Simpson argued that there was no need for another category since what is measured is the potential damage a hurricane’s winds can inflict on human-made structures. Simpson once told The Washington Post that "…when you get up into winds in excess of 155 mph (249 km/h) you have enough damage if that extreme wind sustains itself for as much as six seconds on a building, it’s going to cause rupturing damages that are serious no matter how well it’s engineered."

This is a second video from my sister on #EllicotCity Main Street. This is as high, if not higher than 2 years ago. She is safe for now, no idea if everyone made it out of the 1st floors. @WJZDevin @wjz @FOXBaltimore @CairnsKcairns @wbaltv11 @weatherchannel: video via Kali Harris— Jeremy Harris (@JeremyHarrisTV) May 27, 2018

440 PM – **FLASH FLOOD EMERGENCY** has been issued for Ellicott City in Howard County, Maryland. Significant flash flooding and multiple water rescues have been reported on Main Street in Ellicott City.— NWS DC/Baltimore (@NWS_BaltWash) May 27, 2018

Strong storms bringing heavy rain &potential for flash floods are currently moving across central Maryland. Please use extreme caution, follow all weather advisories& avoid travel if possible. If your area is under a flash flood warning, take precautions and seek higher ground.— Governor Larry Hogan (@GovLarryHogan) May 27, 2018

I have spoken to Howard County Executive Allan Kittleman & am currently heading to Ellicott City. I have directed @MDMEMA to assist in any capacity possible, and numerous other state agencies are providing support. I have declared a State of Emergency. #ECFlood #HoCoMd— Governor Larry Hogan (@GovLarryHogan) May 27, 2018