People have been arguing whether global warming affected the strength of hurricanes Irma and Harvey.
In lieu of the typical arguments, I would like to instead explore the history of Harvey. On Aug. 21, after Harvey finished crossing the Yucatan Peninsula, the National Hurricane Center downgraded the storm from a tropical depression and declared that it was “dissipated” — another way of saying it had died.
For the next two days, the center had nothing to say about Harvey as it remained “dissipated.” Harvey does not reappear in any advisories until 10 a.m. Aug. 23 when it is reclassified as a tropical depression. In just two days, this tropical depression went from a two-day dead storm to a Category 4 hurricane as it intensified over warmer- than-normal waters of the Gulf of Mexico.
While it is normal for storms to lose intensity when crossing land and then reintensify over water, I have never heard of a two-day dead storm reintensify to a major hurricane in just another two days. This was only possible because the waters of the gulf were hotter than normal and these waters were warmer than normal only because of global warming.