Small Craft Advisory
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A small craft advisory is a type of wind warning issued by the
National Weather Service The National Weather Service (NWS) is an Government agency, agency of the Federal government of the United States, United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weathe ...
in the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
. In Canada a similar warning is issued by Environment Canada. It is issued when winds have reached, or are expected to reach within 12 hours, a speed marginally less than
gale A gale is a strong wind; the word is typically used as a descriptor in nautical contexts. The U.S. National Weather Service defines a gale as sustained surface winds moving at a speed of between 34 and 47 knots (, or ).gale warning A gale warning is an alert issued by national weather forecasting agencies around the world in an event that maritime locations currently or imminently experiencing winds of gale force on the Beaufort scale. Gale warnings (and gale watches) a ...
). Inland, this advisory is known as a ''
wind advisory A wind advisory is generally issued by the National Weather Service of the United States when there are sustained thunderstorm winds of and/or gusts of over land. Winds over the said cap will trigger High wind warning, high wind alerts rather tha ...
''. A
lake wind advisory A lake wind advisory is issued by the United States National Weather Service local forecast offices when windy conditions on area lakes are expected to be hazardous for boaters and other recreational events on or around lakes. Example URGENT - WEA ...
is issued for winds just below this range, because unobstructed winds across the open waters of a
lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
are normally faster than across land. The wind speed that triggers the advisory has changed over time. Until the late 1960s, the threshold was 32 to 38 miles per hour (or 28 to 33
knots A knot is a fastening in rope or interwoven lines. Knot may also refer to: Places * Knot, Nancowry, a village in India Archaeology * Knot of Isis (tyet), symbol of welfare/life. * Minoan snake goddess figurines#Sacral knot Arts, entertainme ...
). At some point, the lower limit was reduced to 23 miles per hour (20 knots). Today, however, most places have standardized on 25 to 38 miles per hour (22 to 33 knots), encompassing the combined ranges of forces 6 and 7 on the Beaufort scale. Winds strong enough to trigger a small craft advisory may be referred to as being advisory-force. Conversely, winds just above this intensity (39–57 miles per hour) are called gale-force, and have a separate associated warning. Occasionally an informal lesser advisory, known as "small craft exercise caution", is issued for wind speeds lighter than those that call for a small craft advisory. Criteria for this vary in different localities; sometimes a range of 19 to 24 miles per hour (17 to 21 knots) is observed, or in some places 17 to 23 miles per hour (15 to 19 knots) may be used. The National Weather Service does not specifically identify what constitutes a "small craft". The size of the boat is only part of what a person should consider when venturing out under such a warning. Weight, displacement and hull design are also important factors and an even more important consideration is not only the craft, but the experience of the captain. The next step above these advisories is a
gale warning A gale warning is an alert issued by national weather forecasting agencies around the world in an event that maritime locations currently or imminently experiencing winds of gale force on the Beaufort scale. Gale warnings (and gale watches) a ...
, known as a
high wind warning A gale warning is an alert issued by national weather forecasting agencies around the world in an event that maritime locations currently or imminently experiencing winds of gale force on the Beaufort scale. Gale warnings (and gale watches) al ...
when issued for inland locations. If the winds are associated with a
tropical cyclone A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...
, then the next level above a small craft or wind advisory is a
tropical storm warning Tropical cyclone warnings and watches are alerts issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local popul ...
. Occasionally, such bulletins may also be issued for areas above a particular
elevation The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Vert ...
, as wind speeds tend to increase with
altitude Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context ...
in the
mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited Summit (topography), summit area, and ...
s.


Coastal Warning Display program

As of 15 February 1989, the National Weather Service retired its Coastal Warning Display network nationwide. For over 100 years, display stations were established at yacht clubs, marinas, and
Coast Guard A coast guard or coastguard is a maritime security organization of a particular country. The term embraces wide range of responsibilities in different countries, from being a heavily armed military force with customs and security duties to ...
stations to hoist flags, pennants and colored lights to warn mariners of storms at sea. The display stations were individually notified by the National Weather Service to raise the signals and again to lower them when the hazards passed. The National Weather Service paid for the visual signals; however, the display stations were operated by other agencies or volunteers. Although the Coastal Warning Display program has been formally discontinued, U.S. Coast Guard and other stations may continue to display warning signals without the direct participation of the National Weather Service. Beginning 1 June 2007, U.S. Coast Guard formally re-established a Coastal Warning Display program at selected small boat stations which will hoist display flags to warn of small craft advisories, gale warnings, tropical storm warnings,
storm warning At sea, a storm warning is a warning issued by the National Weather Service of the United States when winds between 48 knots (89 km/h, 55 mph) and 63 knots (117 km/h, 73 mph) are occurring or predicted to occur soon. The wi ...
s,
hurricane warning Tropical cyclone warnings and watches are alerts issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local popul ...
s, and hurricane-force wind warnings. The Coastal Warning Display program was de-emphasized in favor of frequently updated telephone recordings and NOAA Weather Radio. The latter covers the coastal areas of continental United States, Alaska, Hawaii, and the Mariana Islands with continuous weather broadcasts. The major shortcomings of the Coastal Warning Display program were that the displays reached only the small portion of the marine public within sight of them; it cannot convey specific information on movement, intensity, and duration; and the time required to notify the sites by individual telephone calls takes the forecaster away from critical tasks associated with the weather. Further, when users perceive them to be a full substitute for NOAA Weather Radio, other radio broadcasts, and the telephone recordings, they are actually being a disservice.


Canada

A similar warning, known as a ''Strong Wind Warning'', is issued by Environment Canada's
Meteorological Service of Canada The Meteorological Service of Canada (MSC; french: Service météorologique du Canada – SMC) is a division of Environment and Climate Change Canada, which primarily provides public meteorological information and weather forecasts and warnings o ...
from its different offices for the
Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
,
Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
, and
Arctic The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenla ...
waters. These warnings are coordinated for the
Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...
region with American neighboring offices. ''Strong Wind Warning'' was previously referred to as ''Small Craft Warning'' and is still (2012) referred to as such in many publications. A Strong Wind Warning is issued for winds in the range 20–33 knots and wave heights 2–3 metres.


Example of Small Craft Advisory

This is an example of a Small Craft Advisory from the National Weather Service Forecast Office in
Los Angeles Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world' ...
,
California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
.
URGENT - MARINE WEATHER MESSAGE
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
906 PM PDT FRI MAR 16 2012

PZZ670-171215-
/O.NEW.KLOX.SC.Y.0036.120317T0406Z-120317T1600Z/
/O.EXB.KLOX.GL.W.0016.120317T2200Z-120319T1000Z/
/O.UPG.KLOX.GL.A.0010.120318T0000Z-120319T1000Z/
WATERS FROM PT. PIEDRAS BLANCAS TO PT. ARGUELLO AND WESTWARD
60 NM-
906 PM PDT FRI MAR 16 2012

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 9 AM PDT SATURDAY...
...GALE WARNING IN EFFECT FROM 3 PM SATURDAY TO 3 AM PDT MONDAY...

THE NATIONAL WEATHER SERVICE IN LOS ANGELES/OXNARD HAS ISSUED A
GALE WARNING FOR THE WATERS FROM POINT PIEDRAS BLANCAS TO POINT
ARGUELLO AND WESTWARD 60 NM. THIS WARNING IS IN EFFECT FROM 3 PM
SATURDAY TO 3 AM PDT MONDAY. A SMALL CRAFT ADVISORY HAS ALSO BEEN
ISSUED. THIS SMALL CRAFT ADVISORY IS IN EFFECT UNTIL 9 AM PDT
SATURDAY. THE GALE WATCH IS NO LONGER IN EFFECT.

* WINDS...SOUTHWEST WINDS WILL INCREASE TO 10 TO 20 KNOTS WITH
  FREQUENT GUSTS TO 25 KNOTS TONIGHT AND CONTINUE THROUGH SATURDAY
  MORNING. THE WINDS WILL THEN SHIFT TO NORTHWEST AND INCREASE
  THROUGH SATURDAY AFTERNOON. NORTHWEST WINDS 15 TO 25 KNOTS WITH
  FREQUENT GUSTS BETWEEN 35 AND 40 KNOTS WILL DEVELOP LATE
  SATURDAY AFTERNOON AND CONTINUE INTO SUNDAY EVENING. THE WINDS
  WILL BEGIN TO DIMINISH LATE SUNDAY NIGHT.

* SEAS...SHORT-PERIOD AND STEEP HAZARDOUS SEAS BETWEEN 10 AND 12
  FEET WILL DEVELOP SATURDAY AFTERNOON...THEN BUILD TO BETWEEN 15
  AND 20 FEET SATURDAY NIGHT INTO SUNDAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A GALE WARNING MEANS WINDS OF 34 TO 47 KNOTS ARE IMMINENT OR
OCCURRING. OPERATING A VESSEL IN GALE CONDITIONS REQUIRES
EXPERIENCE AND PROPERLY EQUIPPED VESSELS. IT IS HIGHLY
RECOMMENDED THAT MARINERS WITHOUT THE PROPER EXPERIENCE SEEK SAFE
HARBOR PRIOR TO THE ONSET OF GALE CONDITIONS.

A SMALL CRAFT ADVISORY MEANS THAT WIND SPEEDS OF 21 TO 33 KNOTS
ARE EXPECTED TO PRODUCE HAZARDOUS WAVE CONDITIONS TO SMALL CRAFT.
INEXPERIENCED MARINERS...ESPECIALLY THOSE OPERATING SMALLER
VESSELS SHOULD AVOID NAVIGATING IN THESE CONDITIONS.


See also

*
Severe weather terminology (United States) This article describes severe weather terminology used by the National Weather Service (NWS) in the United States. The NWS, a government agency operating as an arm of the National Oceanic and Atmospheric Administration (NOAA) branch of the United ...
*
Severe weather terminology (Canada) This article describes severe weather terminology used by the Meteorological Service of Canada, a branch within Environment and Climate Change Canada. The article primarily describes various weather warnings, and their criteria. Related weather s ...


References


External links


Meteorological Service of Canada




{{DEFAULTSORT:Small Craft Advisory Weather warnings and advisories Nautical terminology