The heat index in Galveston has remained above 100 for over 30 hours.
Even in the dead of night, theres no respite. The Texas Gulf Coast city registered its warmest low temperature on record Thursday.
Washington Post
By Matthew Cappucci
August 9 at 4:29 PM
The heat index hit 100 degrees at 5:52 a.m. Thursday in Galveston, Tex. And, as of Friday afternoon, it hadnt dropped below the century mark since. Its part of a larger heat wave across the Deep South and Southern Plains that shows no signs of letting up through at least next week.
The National Weather Service in Houston issued an excessive heat warning for high heat index values between 108 and 114 degrees during the day on Thursday. Heat advisories stretched over 1,000 miles from the U.S./Mexico border to Georgia, encompassing more than 30 million in the forecast for dangerous heat. Galveston failed to drop below 86 degrees Thursday, marking its warmest all-time low temperature on record! Records there date back to 1874. Galveston also set a daily record high Thursday, hitting 96 degrees.
Sure its summer, and its supposed to be hot. What makes this heat wave noteworthy is the exceptional humidity accompanying it. Its much more difficult to get high temperatures when theres copious water in the air. Its because of waters inherent thermal inertia, or the tendency for water to put the brakes on big temperature swings.
Gulf of Mexico water temperatures are running between 1 and 2 degrees above average. That adds additional water vapor to the air. Thrust atop an environment thats already warming due to climate change, and these sorts of oppressive heat waves are becoming and will continue to be increasingly common in the years ahead.
https://www.washingtonpost.com/weather/2019/08/09/heat-index-galveston-has-remained-above-over-hours-its-part-another-major-heat-wave/