Even though the humidities are expected to remain low today, the temperature is expected to exceed 100 degrees in parts of Georgia near Cobb County on Wednesday June 22, 2022, and the expected high in Cobb itself is 98 degrees.
The NWS defines the heat index as follows on its website:
The heat index, also known as the apparent temperature, is what the temperature feels like to the human body when relative humidity is combined with the air temperature. This has important considerations for the human body’s comfort. When the body gets too hot, it begins to perspire or sweat to cool itself off.
Chart from NOAA showing relationship between relative humidity and temperature in heat index
Here is an excerpt from the hazardous weather outlook:
This Hazardous Weather Outlook is for portions of North and Central Georgia.
.DAY ONE…Today and Tonight…
A Heat Advisory has been issued for east central portions of
Georgia today. Even though humidities remain low, thus not meeting
heat index criteria, maximum temperatures will reach values near
103 degrees within the Advisory area.
.DAYS TWO THROUGH SEVEN…Thursday through Tuesday…
An Excessive Heat Watch has been issued for portions of east
central Georgia for Thursday. Maximum temperatures will reach
values near 105 degrees within the watch area.
A Heat Advisory may be needed for areas mainly along and south of
Macon to Columbus for Friday. Even though maximum temperatures
will be slightly cooler, heat indices may approach 105 degrees due
to an increase in humidities.
The chance for thunderstorms increases a little across a large
portion of the area near the end of the week into the weekend.
The hot weather is expected to last at least through next Tuesday.
The following counties are listed in the outlook:
Baldwin, Banks, Barrow, Bartow, Bibb, Bleckley, Butts, Carroll, Catoosa, Chattahoochee, Chattooga, Cherokee, Clarke, Clayton, Cobb, Coweta, Crawford, Crisp, Dade, Dawson, DeKalb, Dodge, Dooly, Douglas, Emanuel, Fannin, Fayette, Floyd, Forsyth, Gilmer, Glascock, Gordon, Greene, Gwinnett, Hall, Hancock, Haralson, Harris, Heard, Henry, Houston, Jackson, Jasper, Jefferson, Johnson, Jones, Lamar, Laurens, Lumpkin, Macon, Madison, Marion, Meriwether, Monroe, Montgomery, Morgan, Murray, Muscogee, Newton, North Fulton, Oconee, Oglethorpe, Paulding, Peach, Pickens, Pike, Polk, Pulaski, Putnam, Rockdale, Schley, South Fulton, Spalding, Stewart, Sumter, Talbot, Taliaferro, Taylor, Telfair, Toombs, Towns, Treutlen, Troup, Twiggs, Union, Upson, Walker, Walton, Warren, Washington, Webster, Wheeler, White, Whitfield, Wilcox, Wilkes, Wilkinson
The National Weather Service (NWS) is a part of the National Oceanic and Atmospheric Administration (NOAA).
The NWS describes its role as follows:
The National Weather Service (NWS) provides weather, water, and climate forecasts and warnings for the United States, its territories, adjacent waters and ocean areas, for the protection of life and property and the enhancement of the national economy. These services include Forecasts and Observations, Warnings, Impact-based Decision Support Services, and Education in an effort to build a Weather-Ready Nation. The ultimate goal is to have a society that is prepared for and responds to weather, water and climate events.