NWS Alerts

Enable any, or all, of the three National Weather Service (NWS) bulletin categories (warnings, watches and/or advisories) to be alerted when a bulletin is issued for your county. Note that this will also include alerts for assets placed over marine zones as defined by the NWS. NWS alerts are only available to US locations.

Alert Type	Description
NWS Warnings - Community Based	Enable all or none
Tornado Warning	Your location is included in the Area of Maximum Impact (AMI) for a tornado sited by spotters or detected by radar.
Thunderstorm Warning	Your location is included in the AMI for a thunderstorm with spotter or radar detected winds of 58 mph (93 km/h) or greater and/or hail 1 inch (2.5 cm) or greater. Note: The NWS has recently changed the definition of Severe Hail from .75" to 1".
Flood/Flash Flood Warning	Your location is included in the AMI where flash flooding is reported, precipitation estimates indicate flash flooding is likely, or dam/levee failure is imminent or occurring.
NWS Warnings - County Based	Enable all or none.
Tornado Warning	Tornado sited by spotters or detected by radar within the county. Tornado Warnings will flash on the Layered Map.
Thunderstorm Warning	Spotters report or radar detects winds of 58 mph (93 km/h) or greater and/or hail 1 inch (2.5 cm) or greater within the county. Note: The NWS has recently changed the definition of Severe Hail from .75" to 1".
Flood/Flash Flood Warning	Flash flooding is reported, precipitation estimates indicate flash flooding is likely, or dam/levee failure is imminent or occurring within the county.
NWS Watches	Enable all or none.
Tornado Watch	Conditions are favorable for tornadoes.
Thunderstorm Watch	Conditions are favorable for severe thunderstorms.
Flash Flood Watch	Conditions are favorable for flash flooding. Dam/levee failure is possible but not imminent.
NWS Advisories	Enable all or none.
Blowing Snow Advisory	Widespread or localized blowing snow reducing visibilities to ¼-mile (400 m) or less and winds are less than 35 mph (56 km/h).
Fog Advisory	Widespread or localized fog reducing visibilities to ¼-mile (400 m) or less.
Blizzard Advisory	Blizzard conditions expected. Blizzard conditions are defined as the following for at least three hours: sustained wind or frequent gusts of 35 mph (56 km/h), falling or blowing snow, and visibility frequently ¼-mile (400 m) or less.
Snow Advisory	Snow accumulation meeting or exceeding locally defined criteria expected within next 24 hours.
Freezing Rain Advisory	Ice accumulations expected to meet or exceed locally defined criteria.
Winter Weather Advisory	More than one winter weather hazard meeting or exceeding locally defined criteria is expected.
Wind Chill Advisory	Wind chill temperatures reaching or exceeding locally defined criteria are expected.
Frost/Freeze Advisory	Temperatures forecast to reach between 33 and 36°F (.5 and 2°C) for a Frost Advisory and 32°F (0°C) or less for Freeze Advisory.
High Wind Advisory	Sustained winds of 40 mph (64 km/h) or greater for at least one hour or sustained winds of 58 mph (93 km/h) or greater for any period. Winds are not associated with severe local storms.
Heat Advisory	Heat index values reach or exceed locally defined criteria for at least two days.

NWS alerts are not available for Canadian locations.