National Weather Service United States Department of Commerce

SEVERE THUNDERSTORM - a thunderstorm which produces:

hail 1 inch or greater

winds greater than 58 mph

damage to trees, telephone/utility poles or any structure

tornado

 

SEVERE THUNDERSTORM WATCH - issued when severe thunderstorms are possible in and near the watch area (box). The watch is issued for a large area and is usually in effect for several hours.

 

SEVERE THUNDERSTORM WARNING - issued when severe weather is imminent or occurring and is usually in effect for about an hour.

 

TORNADO - a funnel-shaped cloud extending downward from the base of a severe thunderstorm which is rapidly rotating and comes into contact with the ground or any objects on the ground.

 

TORNADO WATCH - issued when severe thunderstorms may produce tornadoes and near the watch area (box). The watch is issued for a large area and is usually in effect for several hours.

 

TORNADO WARNING - issued when a tornado is imminent or occurring and is usually in effect for 45 minutes or less.

 

FUNNEL CLOUD - a funnel-shaped cloud extending downward from the base of a thunderstorm which is rapidly rotating and does NOT come into contact with the ground or objects on the ground.

 

WATERSPOUT - a tornado that occurs over the waters.

FLOOD WATCH (BE PREPARED) - issued when conditions are favorable for flooding. It does not mean flooding will occur, but it is possible.

 

FLASH FLOOD WARNING (TAKE ACTION) - issued when flooding is imminent or occurring. If you are in a flood prone area move immediately to high ground. A flash flood is a sudden violent flood that can take from minutes to hours to develop. It is even possible to experience a flash flood in areas not immediately receiving rain.

 

FLOOD WARNING (TAKE ACTION)  - issued when flooding is imminent or already happening.

 

FLOOD ADVISORY (BE AWARE) - issued when flooding is not expected to be bad enough to issue a warning. However, it may cause significant inconvenience, and if caution is not exercised, it could lead to situations that may threaten life and/or property.

 

CATEGORIES:

MINOR FLOODING - minimal or no property damage, but possibly some public threat or inconvenience.

 

MODERATE FLOODING - some inundation of structures and roads near streams/rivers; some evacuations of people and/or transfer of property to higher ground elevations necessary.

 

MAJOR FLOODING - extensive inundation of structures and roads; significant evacuations of people and/or transfer of property to higher elevations.

HEAT INDEX - what the temperature feels like to the human body based on both the air temperature and humidity.

 

HUMIDITY - the measured amount of moisture in the air.
 

EXCESSIVE HEAT WATCH - issued when extremely dangerous heat conditions are possible.

 

EXCESSIVE HEAT WARNING - issued when extremely dangerous heat conditions are expected. Specifically for heat indices of 105+ degrees for two or more hours for New York State, Connecticut, Massachusetts and Vermont.

 

HEAT ADVISORY - issued when dangerous heat conditions are expected.

  • Heat Indices of 95 degrees or more for two or more consecutive hours for New York State excluding the Lower Hudson Valley, New York City & Long Island and for Vermont.

  • Heat Indices of 95-99 degrees for 2 consecutive days or 100 to 104 degrees for any duration in New York State for the Lower Hudson Valley, New York City & Long Island and for Connecticut & Massachusetts.

AIR QUALITY ALERT - is issued by individual states and your local NWS Forecast Office relays the information via the Air Quality Alert (AQA) product.

 

AIR QUALITY FORECAST  - NWS

TROPICAL DEPRESSION - an organized area of low pressure where sustained surface winds are 38 mph or less.

 

TROPICAL STORM - a strong area of low pressure associated with maximum sustained winds of 39 to 73 mph. It is at this point a tropical cyclone gets a name.

 

HURRICANE - maximum sustained winds of 74 mph or greater.

 

HURRICANE WATCH - an announcement that hurricane conditions are possible within the specified area. Because outside preparedness activities become difficult once winds reach tropical storm force, watches are issued 48 hours in advance of the anticipated onset of tropical-storm-force winds.

 

HURRICANE WARNING - an announcement that hurricane conditions are expected within the specified area. Because outside preparedness activities become difficult once winds reach tropical storm force, warnings are issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.

 

TROPICAL STORM WATCH - an announcement that tropical-storm conditions are possible within the specified area . Because outside preparedness activities become difficult once winds reach tropical storm force, watches are issued 48 hours in advance of the anticipated onset of tropical-storm-force winds.

 

TROPICAL STORM WARNING -  an announcement that tropical-storm conditions are expected within the specified area. Because outside preparedness activities become difficult once winds reach tropical storm force, warnings are issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.

 

HURRICANE LOCAL STATEMENT - issued by your local NWS Forecast Office. NWS Albany can only issue this for Litchfield and Berkshire counties.

 

STORM SURGE is an abnormal rise of water generated by a storm, over and above the predicted astronomical tides.

 

STORM SURGE WATCH: An announcement of the possibility of life-threatening inundation from rising water moving inland from the shoreline somewhere within the specified area, generally within 48 hours, in association with a tropical, subtropical, post-tropical, or potential tropical cyclone.

 

STORM SURGE WARNING: An announcement of the danger of life-threatening inundation from rising water moving inland from the shoreline somewhere within the specified area, generally within 36 hours, in association with a tropical, subtropical, post-tropical, or potential tropical cyclone.

 

‚ÄčNATIONAL HURRICANE CENTER - maintains a continuous watch on tropical cyclones over the Atlantic, Caribbean, Gulf of Mexico, and the Eastern Pacific from 15 May through November 30 and prepares and distributes hurricane watches and warnings for the general public, and also prepares and distributes marine and military advisories for other users. During the "off-season" provides training for U.S. emergency managers and representatives from many other countries that are affected by tropical cyclones and conducts applied research to evaluate and improve hurricane forecasting techniques, and is involved in public awareness programs.

 

Western Atlantic Hurricane Tracking Chart  - NHC

WIND - the movement of air from areas of higher pressure to areas of lower pressure. The greater the difference in pressure the stronger the winds. Wind direction is defined by the direction it is coming from.

 

HIGH WIND WATCH - issued when sustained wind speeds of 40 mph or greater lasting for one hour or longer or for wind gust of 58 mph or greater for any duration or widespread damage are possible.

 

HIGH WIND WARNING - issued when sustained wind speeds of 40 mph or greater lasting for one hour or longer or for wind gusts of 58 mph or greater for any duration or widespread damage are expected.

 

WIND ADVISORY - issued when sustained wind speeds of 31 to 39 mph lasting for one hour or longer or for wind gusts of 46 to 57 mph for any duration are expected.

BLIZZARD WARNING - issued when heavy snow is forecast for 3 hours or more and when sustained winds or frequent gusts of 35 mph are also expected combining to produce blinding snow (visibility near zero / whiteouts) and deep snow drifts.

 

ICE STORM WARNING - issued when 1/2 inch or more of ice accumulations are expected.

 

SNOW SQUALL WARNING - issued to provide advance notice of intense, but limited duration, periods of moderate to heavy snowfall, accompanied by gusty winds resulting in reduced visibilities and whiteout conditions.

 

WINTER STORM WATCH - issued when severe winter conditions are possible including for lake effect snow.

 

WINTER STORM WARNING - issued when severe winter conditions are expected including for lake effect snow. 

 

12-hour Criteria for snow and sleet:

  • 6+ inches: in New York State the North Country, Lower Hudson Valley, New York City & Long Island and for Connecticut, Massachusetts and Vermont.

  • 7+ inches: western and central New York, Finger Lakes, Southern Tier, Mohawk Valley and the Capital District into the mid-Hudson Valley

24-hour Criteria for snow and sleet:

  • 8+ inches: in New York State for the Lower Hudson Valley, New York City & Long Island and for Connecticut & Massachusetts. 

  • 9+ inches: New York State excluding the Lower Hudson Valley, New York City & Long Island and for Vermont.

 

WINTER WEATHER ADVISORY - issued when winter conditions are expected to cause significant inconvenience and may be hazardous including for lake effect snow.

 

Snow and/or Sleet Criteria:

  • 3 inches: in New York State for the Lower Hudson Valley, New York City & Long Island and for Connecticut & Massachusetts.

  • 4 inches: New York State excluding the Lower Hudson Valley, New York City & Long Island & for Vermont.

Freezing Rain & Freezing Drizzle Criteria: any accumulation of ice 

 

WINTRY MIX - a mixture of snow, sleet and/or freezing rain.

WIND CHILL what the temperature feels like on human based on both air temperature and wind speed.

 

WIND CHILL ADVISORY - issued when potentially dangerous wind chill readings are expected.

  • Wind Chill readings of 15 to 24 degrees below zero: western and central New York, Finger Lakes, Southern Tier, mid/lower Hudson Valley, New York City, Long Island and for Connecticut & Massachusetts.

  • Wind Chill readings of 20 to 29 degrees below zero: in New York State the North County, Mohawk Valley, Capital District and for Vermont.

WIND CHILL WATCH - issued when life-threatening wind chill readings are possible.

 

WIND CHILL WARNING - issued when life-threatening wind chill readings are expected.

  • Wind Chill readings of 25 degrees below zero or lower: western and central New York, Finger Lakes, Southern Tier, mid/lower Hudson Valley, New York City, Long Island and for Connecticut & Massachusetts.

  • Wind Chill readings of 30 degrees below zero or lower: in New York State the North County, Mohawk Valley, Capital District and for Vermont.

FROST ADVISORY - issued when widespread frost is expected during the growing season.

 

FREEZE WARNING - issued 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.

 

Maps: First Fall FreezeLast Spring Freeze

DENSE FOG ADVISORY - issued when widespread dense fog develops. When this happens, visibilities frequently drop to one-quarter of a mile or less. These conditions make travel difficult.