Decent hurricane records began after "hurricane hunters" started surveillance of the Atlantic Basin in the 1940’s.
The satellite age in the 1970’s gave us more detailed hurricane information.
Surface anemometers (wind speed gauges) and damage photos are the true measure of a hurricane's intensity when it hits land .
The Saffir-Simpson hurricane scale is defined by sustained winds at a defined elevation (height off the ground).
Photos of surface damage, palm tree damage, etc. have been consistent with wind speed measured by anemometers.
Harvey was mostly a Category 1 storm at US landfall.
There was one band of Category 2 winds -- one NDBC station had sustained winds of Category 2 strength for about 4 hours.
Photos of surface damage are mostly consistent with Category 1 winds, except for Category 2 damage from Rockport, Texas to the coast.
Irma was not a hurricane at US landfall -- it was a tropical storm.
Irma was not a hurricane at the Florida keys, or at Naples, Florida.
There are no surface stations anywhere in Florida with reported sustained winds over the 64 knot threshold for a Category 1 hurricane.
NDBC buoys recorded sustained surface winds in the path of Irma eye wall of 60 knots sustained.
All the photos of surface damage are consistent with tropical storm force winds.
At Naples, the 56 knots peak SUSTAINED winds for Irma were well below the 64 knot Saffir-Simpson scale for Category 1.
For Irma, no NDBC station showed winds reaching the Category 1 threshold for 10 meters above the surface ... except:
(1) The Fowey Rock station (anemometer height 44 meters)
(2) MLRF1 station Molasses Reef reached maximum of 30.9 meters per second (anemometer height is 15.8 meters)
The 10 meter standard height for anemometers is used to define the Saffir-Simpson hurricane scale.
The Category 1 hurricane threshold for SUSTAINED wind speed is 33 meters per second, at 10 meters off the ground.
Hurricanes normally form out in the Atlantic Ocean.
The Northern Atlantic chart below shows no warming trend for at least 20 years, during which 30% of all manmade CO2 emissions have taken place:
The Southern Atlantic chart below shows no warming trend for 30 years, during which 40% of all manmade CO2 emissions have taken place:
The record-setting twelve-year long hurricane “drought” is ignored (no major hurricane landfalls on the US from 2005 to 2017).
Leftists immediately published stories declaring Harvey and Irma to be caused (or worsened) by anthropogenic (man made) climate change.
The stories were not based on data, or quantitative analysis.
The bottom line comes from NOAA’s Geophysical Fluid Dynamics Laboratory:
“Global Warming and Hurricanes – An Overview of Current Research Results.”
Summary:
“It is premature to conclude that human activities–and particularly greenhouse gas emissions that cause global warming – have already had a detectable impact on Atlantic hurricane or global tropical cyclone activity. …”