Montauk Point NY to Sandy Hook NJ out 20 nautical miles
including Long Island Sound and New York Harbor
Beach Erosion: The carrying and wearing away of beach materials, such as
sand or rocks, by wave action, currents tides or wind.
Beaufort Scale: A scale that indicates the wind speed using the effect
wind has on certain familiar objects.
"Bomb": Indicates an expected rapid intensification of a
cyclone (low pressure) with surface pressure expected to fall by at least 24 millibars in 24
Coastal Flooding: The inundation of land areas along the ocean coast
caused by sea waters over and above normal tidal action that may be originate from the ocean front,
back bays, sounds, or other bodies of ocean water.
Warning: Issued when tidal flooding or storm induced flooding is occurring,
imminent or highly likely along coastal areas within approximately the next 12 hours.
Watch: Issued when conditions are favorable for tidal flooding or storm induced
flooding along coastal areas within approximately 12 to 36 hours.
Waters: The marine area, including bays, harbors and sounds extending from the
coast to 20 nautical miles offshore.
Crest: Highest point in a wave.
Fathom: Unit of depth in the ocean equal to 6 feet.
Fetch: The marine area in which waves are generated by winds consisting
of a near constant direction and speed.
Freezing Spray: An accumulation of freezing water droplets on a vessel
caused by a combination of the wind, water, air temperature and vessel temperature.
Gale Warning: Issued for sustained winds or frequent gusts of 34 to 47
knots, not associated with a tropical system.
Heavy Surf: Large waves breaking on or near the shore resulting from
swells spawned by a distant storm.
Heavy Surf Advisory: Issued for heavy surf that poses a threat to life
High: An area of high pressure usually accompanied by anticyclonic
(clockwise) outward flow.
That portion of the Atlantic Ocean which extends from 20 to 40 nm off the East Coast to 35
Hurricane Force Wind Warning: Issued for sustained winds or frequent
gusts of 64 knots or greater, not associated with a tropical systems.
Knot: Is equal to 1 nautical miles per hour or 1.15 statue miles (the
length of 1 minute latitude) per hour.
Land Breeze: A wind that blows from the land towards a body of water.
Also known as an offshore breeze. It occurs when the land is colder than the water.
Lightning: Any form of visible electrical discharges produced by
Low: An area of low pressure usually accompanied by cyclonic
(counterclockwise) inward flow.
Statement: Issued to provide mariners with details on significant or potentially
Mean Lower Low Water: A tidal datum which corresponds to the average
mean of the lower low tide heights of a mixed tide observed over a specific 19 year
Nautical Mile (nm): Unit of distance used for marine navigation and is
equal to 1.15 statue miles.
Neap Tide: Occurs at the first and third quarters of the moon.
Waters: The portion of the ocean, gulfs and seas beyond the coastal waters
extending to a specified distance from the coastline (usually 100 nm), a specified depth, or
covering an area defined by specific latitude and longitude points.
Rip Currents: Are narrow
channels of water flowing seaward from the beach through breaking waves in the surf zones. They can
rapidly carry a person into deeper waters.
SeaBreeze: A wind that flows from a sea or ocean towards a land mass.
Also known as an onshore breeze. It occurs when the land is warmer than the water.
Significant Wave Height: is the wave height that is measured and
forecast. It is the average wave height of the highest 1/3 of all individual waves, which
corresponds closely to the visually observed mean wave height. Generally, it is assumed that
individual wave heights can be described using a Rayleigh distribution.
Example: Significant Wave Height = 10 ft
1 in 10 waves to be larger than 11 ft
1 in 100 waves to be larger than 16 ft
1 in 1000 waves to be larger than 19 ft
Small Craft Advisory: Issued for sustained winds or frequent gusts of 25
to 33 knots and/or seas 5 feet or higher.
Warning: Issued to convey information regarding hazardous convective activity or
other short-term weather events occurring over the water or which may impact those on the water. For
brief or sudden occurrence of sustained winds or frequent gusts 34 knots or greater. Usually in
association with thunderstorms and/or waterspouts.
Spring Tide: Tides of increased range or tidal currents of increased
speed that occur semimonthly as a result of the new moon or the full moon.
Squall: A sudden wind increase characterized by a duration of minutes
and followed by a sudden decrease in winds (an increase in wind speed of 16 knots or more and
sustained at 20 knots or more for at least 1 minute).
St. Elmo's Fire: The glow on a masthead produced by an extreme
buildup of electrical charge. Unprotected mariners should immediately move to shelter when this
phenomena occurs. Lightning may strike the mast within five minutes after it begins to
Storm Surge: The difference between the astronomical tide and the
Storm Tide: The actual water level resulting from the astronomical tide
plus the storm surge.
Storm Warning: Issued for sustained winds or frequent gusts 48 to 63
knots, not associated with a tropical system.
Swell: Wind generated waves that have traveled out of their area of
origin. Swells exhibit smoother, more regular and uniform crests and longer wave periods than wind
waves. Swell direction is the direction from which the swells are propagating.
Swell Direction: Is the direction from which the swells are
Surf: The waves in the area between the shoreline and the outermost
limit of breakers.
Tidal Piling: Abnormally high water levels caused by an accumulation of
successive incoming tides that do not allow the water to completely drain due to opposing strong
winds and/or waves/swells.
Tide: The periodic rise and fall of water resulting from the
gravitational interactions between the Earth, Moon and Sun.
Tide Anomaly: Actual water level minus the tide table
Tide Cycle: The periodic changes in the intensity of tides caused
primarily by the varying relations between the Earth, Moon and Sun.
Tropical Weather Terms -
Tropical Prediction Center
Trough: Lowest point in a wave.
Waterspout: A tornado over water - a rapidly rotating column of air
extending from the a cumulonimbus cloud with a circulation that reaches the surface of
Wave Height: Height from crest to trough.
Wave Length: Distance from crest (trough) to the next crest
Wave Period: Time between consecutive crests (troughs) to pass a fixed
Wind Wave: Local waves of short period generated from the action of wind
only on the water surface.
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