Wednesday, November 13, 2019

Hurricanes


US Landfall Hurricanes - The number of US landfall hurricanes since 1850 ranged between 14 and 23 per year. From 1850 to 1900 we had 93 landfall hurricanes. From 1900 to 1950 we had 93. The average is 18.6 per decade.  From 1950 to 2000 we had 73. The average is 14.6 per decade. Since 2000 we’ve had 30. The average is 15 per decade. These only affect coastal areas. Hurricanes appear to be declining. The number of US landfall hurricanes is listed by decade below.
1850s 16
1860s 15
1870s 18
1880s 23
1890s 21
1900s 17
1910s 20
1920s 15
1930s 18
1940s 23
1950s 16
1960s 15
1970s 12
1980s 16
1990s 14
2000s 19
2010s 11

Since 2010 we’ve had 11 landfall hurricanes
Year-Name-States- Cat-Wind-Month
2018 Michael - FL GA 5-140 Oct.
2018 Florence NC 1-80 Sep
2017 Nate LA MS 1-65 Oct
2017 Irma FL 4-115 Sep
2017 Harvey TX 4-115 Aug
2016 Matthew FL GA SC NC 2-85 Oct
2016 Hermine FL 1-70 Sep
2015 none
2014 Arthur NC 2-85 Jul
2013 none
2012 Sandy NY NJ 7-65 Oct
2012 Isaac LA 1-70 Aug
2011 Irene NC 1-75 Aug
2010 none

Hurricanes form near the equator over warm ocean waters, where the ocean is at least 80 degrees F for at least the top 50 meters (about 165 feet) below the surface.

The term hurricane is used only for the large storms that form over the Atlantic Ocean or eastern Pacific Ocean. The term cyclone is used elsewhere.

The second ingredient for a tropical cyclone is wind.

In the case of hurricanes that form in the Atlantic Ocean, the wind blowing westward across the Atlantic from Africa provides the necessary ingredient. As the wind passes over the ocean's surface, water evaporates (turns into water vapor) and rises. As it rises, the water vapor cools, and condenses back into large water droplets, forming large cumulonimbus clouds. These clouds are just the beginning.
Hurricane Category Wind Speeds
1            74-95
2            96-110
3            111-129
4            130-156
5            157+
Norb Leahy, Dunwoody GA Tea Party Leader

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