Most Common NWS Local Weather Advisory Types and Definitions
(In Alphabetical Order)

Blizzard Warning

Issued by a local NWS forecast office when sustained or frequent winds of 35 mph or higher and considerable falling and/or blowing snow that frequently reduces visibility to 1/4 of a mile or less are expected. The warning is issued when these conditions are expected to prevail for a minimum of 3 hours. There is no temperature criterion factored into a Blizzard Warning.

Dense Fog Advisory

Issued by a local NWS forecast office when widespread dense fog reducing visibility to less than 1/4 mile is expected to occur.

Flash Flood Warning

Issued by a local NWS forecast office when flooding will create an immediate threat to life and/or property. The flooding can be due to torrential rains, dam failure, or an ice jam and generally occurs in a time period of less than 6 hours. Flash Flood Warnings are generally issued for counties and or parts of counties.

Flood Warning

Issued by a local NWS forecast office when flooding due to torrential rains, dam failure, or an ice jam will occur in a time period generally greater than 6 hours. Flood Warnings are also issued for specific rivers or parts of rivers when the water is expected to rise above flood stage. River Flood Warnings can remain in effect for many days.

Flood Watch

Issued by a local NWS forecast office when a potential for flooding exists.

Freeze Warning

Issued by a local NWS forecast office when temperatures of 32 degrees or below are expected over an extensive area for a significant period of time (several hours) during the growing season.

Freezing Rain Advisory

Issued by a local NWS forecast office when ice accumulations of less than 1/4 inch are expected to occur due to light freezing rain or freezing drizzle.

Frost Advisory

Issued by a local NWS forecast office when temperatures are expected to drop to between 33 and 36 degrees allowing for scattered frost to form during the growing season.

Heat Advisory

Issued by a local NWS forecast office when heat indices are expected to range from 105 to less than 115 degrees for at least 3 hours during the day.

Heavy Snow Warning

Issued by a local NWS forecast office when snow is expected to accumulate to 6 inches or more in 12 hours or less, or 8 inches or more in 24 hours or less.

High Wind Warning

Issued by a local NWS forecast office when sustained wind speeds of 40 mph or greater lasting for one hour or longer, or for winds of 58 mph or greater for any duration are expected.

High Wind Watch

Issued by a local NWS forecast office when sustained wind speeds of 40 mph or greater lasting for one hour or longer, or for winds of 58 mph or greater for any duration are possible.

Ice Storm Warning

Issued by a local NWS forecast office when accumulations of ice due prolonged freezing rain are expected to exceed 1/2 inch.

Lake Effect Snow Advisory

Issued by a local NWS forecast office when lake induced snows of 4"-7" inches are expected.

Lake Effect Snow Warning

Issued by a local NWS forecast offices when lake induced snows of 7+ inches are expected.

Lake Effect Snow Watch

Issued by a local NWS forecast office when lake induced snows of 7+ inches are possible within the next 24 to 48 hours.

Red Flag Warning

Issued by a local NWS forecast office when ambient dry conditions could lead to increased brush fire danger when the following criteria are met. A sustained wind average of 15 mph or greater must occur with the average relative humidity dropping to 25% or less, along with air temperatures of 75 degrees F or higher.

Severe Thunderstorm Warning

Issued by a local NWS forecast office when severe weather due to a thunderstorm is imminent or occurring. In the Northeast, a severe thunderstorm produces damaging winds in excess of 58 mph, hail 3/4 of an inch in diameter or greater, and/or tornadoes. A warning is issued for a county or part of a county and is usually in effect for about an hour. The amount of lightning plays no role in whether or not a severe thunderstorm warning is issued.

Severe Thunderstorm Watch

Issued by the Storm Prediction Center located in Norman, OK when conditions are favorable for the development of severe thunderstorms at a later time. In the Northeast a severe thunderstorm produces winds in excess of 58 mph, hail 3/4 of an inch in diameter or greater, and/or tornadoes. A watch is issued for a large area and is usually in effect for six hours.

Snow Advisory

Issued by a local NWS forecast office when snow is expected to accumulate to between three and five inches.

Tornado Warning

Issued by a local NWS forecast office when a tornado has been sighted or is indicated on Doppler weather radar. A warning is issued for a county or part of a county and is typically in effect for about an hour.

Tornado Watch

Issued by the Storm Prediction Center in Norman, OK when conditions are favorable for severe thunderstorms and tornadoes. The watch is issued for a large area and is usually in effect for six hours.

Urban and Small Stream Flood Advisory

Issued by a local NWS forecast office to alert the public to minor poor drainage and urban street flooding or small stream flooding that poses an inconvenience but no threat to life and property.

Wind Advisory

Issued by a local NWS forecast office when sustained wind speeds of 31 to 39 mph lasting for one hour or longer or for winds of 46 to 57 mph for any duration are expected.

Wind Chill Advisory

Issued by a local NWS forecast office when potentially dangerous wind chill readings are expected.

A wind chill advisory issued for the following local counties, Berkshire, Columbia, Dutchess, Greene, Litchfield, and Ulster when wind chill values are expected to range from 15 to 24 degrees below zero.

A wind chill advisory is issued for the following local counties, Albany, Bennington, Delaware, Fulton, Hamilton, Herkimer, Montgomery, Otsego, Rensselaer, Saratoga, Schoharie, Schenectady, Washington and Warren, when wind chill values are expected to range from 20 to 29 degrees below zero.

Wind Chill Warning

Issued by a local NWS forecast office when dangerously low wind chill readings are expected.

A wind chill warning is issued for the following local counties, Berkshire, Columbia, Dutchess, Greene, Litchfield, and Ulster, when wind chill values expected to drop below 25 degrees below zero.

A wind chill warning is issued for the following local counties, Albany, Bennington, Delaware, Fulton, Hamilton, Herkimer, Montgomery, Otsego, Rensselaer, Saratoga, Schoharie, Schenectady, Washington and Warren, when wind chill values are expected to drop below 30 degrees below zero.

Wind Chill Watch

Issued by your local NWS forecast office when dangerously low wind chill readings below 25 degrees below zero are possible.

Winter Storm Warning

Issued by a local NWS forecast office when severe winter conditions are expected. Severe winter conditions include snow accumulations of seven inches or greater or a combination of heavy snow, sleet, and freezing rain is expected to cause significant disruption to daily activities and travel.

Winter Storm Watch

Issued by a local NWS forecast office when severe winter conditions (heavy snow and/or significant ice accumulations or any combination) are possible within the next 24 to 48 hours.

Winter Weather Advisory

Issued by a local NWS forecast office when hazardous winter weather conditions are occurring, imminent or likely. A winter weather advisory is issued when a combination of two or more of the following events; snow, freezing rain or drizzle, sleet, or blowing snow is expected to fall at light to moderate rates causing inconvenience to daily activities and travel.