National Weather Service Alerts

The National Weather Service Forecast Office in Peachtree City along with the Storm Prediction Center in Norman, Oklahoma provides weather watches, warnings, and advisories to alert the public of hazardous weather conditions. For a description of the various watches, warnings, and advisories, please see below.

Winter Weather Alerts
Winter Weather Advisory	Issued when, within the next 24 hours, there is a high probability of enough snow, sleet, or ice to cause inconvenience, but not enough to warrant a warning.
Winter Storm Watch	Issued when there is at least a 50 percent chance for winter storm conditions occurring in the next 12 to 48 hours. Winter storm conditions include an accumulation of at least a half-inch of sleet, and/or a significant accumulation (1/4 inch or more) of ice due to freezing rain, and/or heavy snow accumulation. Snow accumulations must be at least 2 inches (except 3 inches in the Northeast Georgia Mountains) within a 12-hour period, or at least 4 inches in a 24-hour period.
Winter Storm Warning	Issued when there is at least an 80 percent chance for winter storm conditions occurring within the next 24 hours. Winter storm conditions include an accumulation of at least a half-inch of sleet, and/or a significant accumulation (1/4 inch or more) of ice due to freezing rain, and/or heavy snow accumulation. Snow accumulations must be at least 2 inches (except 3 inches in the Northeast Georgia Mountains) within a 12-hour period, or at least 4 inches in a 24-hour period.
Ice Storm Warning	Issued when there is at least an 80 percent chance that freezing rain will result in the accumulation of at least 1/4 inch of ice within the next 24 hours.
Blizzard Watch	Issued when there is at least a 50 percent chance for blizzard conditions within the next 12 to 48 hours. Blizzard conditions consist of sustained wind speeds (or gusts) of at least 35 mph and considerable falling or blowing snow causing a reduction of visibilities to less than 1/4 mile for at least 3 hours.
Blizzard Warning	Issued when there is at least an 80 percent chance that wind and snow will combine to produce blizzard conditions within the next 24 hours. Blizzard conditions consist of sustained wind speeds (or gusts) of at least 35 mph, and considerable falling or blowing snow causing a reduction of visibilities to less than 1/4 mile for at least 3 hours.
Frost Outlook	Issued when, within the next 24 to 48 hours, there is a moderate probability (50percent – 70 percent) of significant frost. These are issued on, or after March 20 in spring, and prior to November 20 in autumn. In autumn, the issuance of Frost Outlooks will be discontinued prior to November 20 if temperatures fall below 28°F over a wide area.
Frost Advisory	Issued when, within the next 24 hours, there is a high probability (at least 80 percent) of significant frost. These are issued on, or after March 20 in spring, and prior to November 20 in autumn. In autumn, the issuance of Frost Advisories will be discontinued prior to November 20 if temperatures fall below 28°F over a wide area.
Freeze Watch	Issued when, during the next 12 to 48 hours, there is at least a moderate degree of confidence (50 percent  – 70 percent) that temperatures will drop to 32°F or lower. These are issued on, or after March 20 in spring, and prior to November 20 in autumn. In autumn, the issuance of Freeze Watches will be discontinued prior to November 20 if temperatures fall below 28°F over a wide area.
Freeze Warning	Issued when, during the next 24 hours, there is a high degree of confidence (at least 65%) that temperatures will drop to 32°F or lower. These are issued on, or after March 20 in spring, and prior to November 20 in autumn. In autumn, the issuance of Freeze Warnings will be discontinued prior to November 20 if temperatures fall below 28°F over a wide area. After November 20, if temperatures are expected to fall low enough to cause damage (i.e. broken water pipes), a Special Weather Statement (SPS) will be issued.
Wind Chill Advisory	Issued when, within the next 24 hours, there is a high probability of wind chill readings below zero degrees, but not low enough to warrant a warning.
Wind Chill Watch	Issued when there is at least a 50 percent chance for wind chill values to drop below minus 15 degrees within the next 12 to 48 hours.
Wind Chill Warning	Issued when there is at least an 80 percent chance that wind chill values will drop to at least 15 degrees below zero within the next 24 hours.
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Severe Weather Alerts
Severe Weather Statement	A brief, concise statement to provide specific information on observed severe weather.
Significant Weather Advisory	Issued for strong thunderstorms producing frequent or excessive amounts of cloud-to-ground lightning, and/or heavy downpours that may result in minor nuisance flooding or street flooding. Also issued for strong thunderstorms producing hail or strong wind, but not meeting official "severe" criteria. It is typically issued for an hour or less and for only a few counties.
Tornado Watch	A Tornado Watch outlines an area where the possibility exists for large hail, damaging winds, and the possibility of multiple tornadoes to develop.
Tornado Warning	A warning issued to warn the public of an existing, imminent, or suspected tornado. A tornado is a violently rotating column of air, usually pendant to a thunderstorm, with circulation reaching the ground.
Severe Thunderstorm Watch	A Severe Thunderstorm Watch outlines an area where an organized episode of hail 1 inch diameter or larger and/or damaging thunderstorm winds are expected.
Severe Thunderstorm Warning	A warning issued to warn the public of an existing, imminent, or suspected severe thunderstorm. A severe thunderstorm is a thunderstorm that produces a tornado, winds of at least 50 knots (58 mph), and/or hail at least 1 inch in diameter (the size of pennies). Note: Structural wind damage may imply the occurrence of a severe thunderstorm.
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Flooding Alerts
Flash Flood Warning	A warning issued to warn the public that flash flooding is imminent or in progress. A flash flood is a flood which is caused by heavy or excessive rainfall in a short period of time, generally less than 6 hours. Also, a dam failure can cause a flash flood.
River Flood Warning	Issued when the river stage at a "forecast point" is expected to reach or exceed bank full (flood stage), causing the inundation of a normally dry area.
Areal Flood Warning	For all areas other than "forecast points," used to issue a flood warning in situations where flooding is expected to occur more than 6 hours after a heavy rain event. Also issued when flash flooding persists longer than 6 hours.
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Special Weather Alerts
Special Weather Statement	Issued to convey information about an upcoming weather event that is expected to be significant, but not meeting criteria for a watch, warning, or advisory.
Wind Advisory	Issued when, during the next 24 hours, there is at least an 80 percent chance of wind speeds 20 to 35 mph lasting for one hour or longer or when wind gusts of at least 35 mph are expected.
High Wind Watch	Issued when, during the next 48 hours, there is at least a 50 percent chance of sustained wind speeds of at least 36 mph lasting 1 hour or more. Also issued when there is a 50 percent chance of a wind gust of 45 mph.
High Wind Warning	Issued when, during the next 24 hours, there is at least an 80 percent chance of sustained wind speeds of at least 36 mph lasting 1 hour or more. Also issued when there is an 80 percent chance of a wind gust of at least 45 mph.
Dense Fog (or smoke) Advisory	Issued when, during the next 24 hours, there is at least an 80 percent chance of widespread visibility restrictions of 1/4 mile or less.
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Tropical Storm Alerts
Tropical Storm Watch	Issued when, during the next 48 hours, there is a least a 50 percent chance of wind speeds between 39 and 73 mph occurring in association with a land-falling tropical storm.
Tropical Storm Warning	Issued when, during the next 36 hours, there is a least an 80 percent chance of wind speeds between 39 and 73 mph occurring in association with a land-falling tropical storm.
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Heat-Related Alerts
Heat Advisory	Issued when there is at least an 80 percent chance that daytime heat indices will exceed 104°F for at least 2 consecutive days.
Excessive Heat Warning	Issued when there is at least an 80 percent chance that daytime heat indices will exceed 109°F for at least 2 consecutive days.
Excessive Heat Watch	Issued when there is at least a 50 percent chance that daytime heat indices will exceed 109°F for at least 2 consecutive days.
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