The National Weather Service is warning of isolated to scattered thunderstorms and extreme heat across north and central Georgia today, with potentially strong storms and high heat index values expected to continue through the weekend.

The National Weather Service issued a hazardous weather outlook for Cobb County and other parts of north and central Georgia

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
and evening, capable of producing gusty winds, frequent lightning,
and locally heavy rainfall. Maximum heat index values will reach
99 to 104 degrees for all except far northeastern Georgia.

.DAYS TWO THROUGH SEVEN…Wednesday through Monday…

Coverage of afternoon and evening thunderstorms will gradually
increase through the week. The probability for widespread severe
weather is low, but a few strong to severe storms will be possible
each day.

Heat index values will reach 97 to 105 degrees across portions of
central and eastern Georgia each afternoon through Saturday.
Precautions should be taken to avoid heat related illnesses.

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:
Isolated thunderstorms are 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:
Scattered thunderstorms are 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.

In summary, isolated thunderstorms are fewer in number and more localized, covering a smaller area with significant gaps between storms, while scattered thunderstorms are more widespread, covering a larger area with numerous individual storms occurring somewhat randomly across the forecast area.

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.”