The National Weather Service is warning of heat indices reaching up to 105 degrees and the possibility of thunderstorms across north and central Georgia through the weekend.

The National Weather Service issued a hazardous weather outlook for Cobb County and other parts of north and central Georgia from Wednesday through the weekend.

Bonus for the more weather-curious among you … To read an article about interpreting a weather news report with some of the typical terminology defined, follow this link.

What is in the statement?

The statement gives the following details:

This Hazardous Weather Outlook is for north and central Georgia.

.DAY ONE…Today and Tonight…

Isolated to scattered thunderstorms are possible this afternoon across most of central and north Georgia. Storms will be possible of heavy rainfall, frequent lightning, and gusty winds.

Heat indices this afternoon will reach between 100 and 105.

.DAYS TWO THROUGH SEVEN…Thursday through Tuesday…

Scattered to widespread thunderstorms are expected Thursday through Sunday. The threat for organized severe weather remains low, but very heavy rainfall and localized flooding will be possible.

Heat index values will range from 100 to 105 degrees, possibly higher, across portions of north and central Georgia each day.

What counties are affected?

The following counties are included in the hazardous weather 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

What is meant by “isolated” and “scattered”?

The NWS defines “isolated” as follows:

A National Weather Service convective precipitation descriptor for a 10 percent chance of measurable precipitation (0.01 inch). Isolated is used interchangeably with few.

“Scattered” has the following definition:

When used to describe precipitation (for example: “scattered showers”) – Area coverage of convective weather affecting 30 percent to 50 percent of a forecast zone(s).

Isolated thunderstorms and scattered thunderstorms are two terms used to describe different distributions of thunderstorm activity within a particular area. The main difference lies in the extent of coverage and how the thunderstorms are spatially distributed:

• Isolated Thunderstorms: Relatively rare occurrences that happen sporadically and are generally confined to a limited area. These thunderstorms are often characterized by being few and far between, with significant gaps between individual storm cells. Typically, isolated thunderstorms cover less than 20% of the forecast area. Despite their isolated nature, these storms can still be intense and may produce heavy rain, lightning, gusty winds, and possibly hail.
• Scattered Thunderstorms: More widespread than isolated thunderstorms and cover a larger portion of the forecast area. In a scattered thunderstorm scenario, numerous individual thunderstorms develop, but they are not continuous or widespread enough to be classified as a “line” or “cluster” of storms. Scattered thunderstorms generally cover between 30% to 50% of the forecast area. Although scattered thunderstorms are more widespread, they still leave considerable gaps between storm cells, and not everyone within the forecast area will necessarily experience a thunderstorm.

About the National Weather Service

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.”