The Beaufort scale is an empirical measure that relates wind speed to observed conditions at sea or on land. Its full name is the Beaufort wind force scale.
A tornado watch is a severe weather watch product of the National Weather Service that is issued by national weather forecasting agencies when meteorological conditions are favorable for the development of severe thunderstorms capable of producing tornadoes. In addition to the potential for tornado development, thunderstorms that develop within the watch area may contain large hail, straight-line winds, intense rainfall and/or flooding that pose a similar damage risk as the attendant tornado threat. A tornado watch does not mean a tornado is active or will appear, just that favorable conditions increases the likelihood of such happening. A watch must not be confused with a tornado warning.
A severe thunderstorm watch is a statement issued by weather forecasting agencies to advise the public that atmospheric conditions in a given region may lead to the development of severe thunderstorms within the region over several hours. The criteria for issuing a watch varies from country to country and may also include torrential rainfall and tornadoes. A watch may also be issued several hours ahead of the arrival of a mature and organized complex of storms, such as a mesoscale convective system.
A severe thunderstorm warning is a type of public warning for severe weather that is issued by weather forecasting agencies worldwide when one or more severe thunderstorms have been detected by Doppler weather radar, observed by weather spotters, or reported by an emergency management agency, law enforcement, or the general public. Unlike a watch, a warning is issued to areas in the direct path of active severe thunderstorms, that are expecting a direct impact typically within an hour. Severe thunderstorms can cause property damage and injury due to large hail, high winds, and flooding due to torrential rainfall. The exact criteria to issue a warning varies from country to country.
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. Forecasters typically issue gale warnings when winds of this strength are expected. In the United States, a gale warning is specifically a maritime warning; the land-based equivalent in National Weather Service warning products is a wind advisory.
A small craft advisory is a type of wind warning issued by the National Weather Service in the United States. 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 force. A Small Craft Advisory may also be issued when sea or lake ice exists that could be hazardous to small boats.
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 population and civil authorities to make appropriate preparation for the cyclone, including evacuation of vulnerable areas where necessary. It is important that interests throughout the area of an alert make preparations to protect life and property, and do not disregard it on the strength of the detailed forecast track.
A winter storm warning is a hazardous weather statement issued by Weather Forecast Offices (WFO) of the National Weather Service (NWS) in the United States to alert the public that a winter storm is occurring or is about to occur in the area, usually within 36 hours of the storm's onset.
At sea, a storm warning is a warning issued by the National Weather Service of the United States when winds between 48 knots and 63 knots are occurring or predicted to occur soon. The winds must not be associated with a tropical cyclone. If the winds are associated with a tropical cyclone, a tropical storm warning will be substituted for the storm warning and less severe gale warning.
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 States Department of Commerce (DoC), defines precise meanings for nearly all of its weather terms.
Hurricane Esther was the first large tropical cyclone to be discovered by satellite imagery. The fifth tropical cyclone, named storm, and hurricane of the 1961 Atlantic hurricane season, Esther developed from an area of disturbed weather hundreds of miles west-southwest of the southernmost Cape Verde Islands on September 10. Moving northwestward, the depression strengthened into Tropical Storm Esther on September 11, before reaching hurricane intensity on the following day. Early on September 13, Esther curved westward and deepened into a major hurricane. The storm remained a Category 3 hurricane for about four days and gradually moved in a west-northwestward direction. Late on September 17, Esther strengthened into a Category 5 hurricane with sustained winds of 160 mph (260 km/h) on September 18. The storm curved north-northeastward on September 19, while offshore of North Carolina. Esther began to weaken while approaching New England and fell to Category 3 intensity on September 21. The storm turned eastward early on the following day, and rapidly weakened to a tropical storm.
Hurricane Gustav was a Category 2 hurricane that paralleled the East Coast of the United States in September 2002 during the 2002 Atlantic hurricane season. It was the seventh named storm and first hurricane of the season. Initially a subtropical depression north of the Bahamas, Gustav passed just to the east of the Outer Banks, North Carolina as a tropical storm before traveling northeastward, making two landfalls in Atlantic Canada as a Category 1 hurricane. The storm was responsible for one death and $100,000 in damage, mostly in North Carolina. The interaction between Gustav and a non-tropical system produced strong winds that caused an additional $240,000 (2002 USD) in damage in New England, but this damage was not directly attributed to the hurricane.
Tropical cyclone windspeed climatology is the study of wind distribution among tropical cyclones, a significant threat to land and people. Since records began in 1851, winds from hurricanes, typhoons and cyclones have been responsible for fatalities and damage in every basin. Major hurricanes usually cause the most wind damage. Hurricane Andrew for example caused $45 billion(2005 USD) in damage, most of it wind damage.
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 scales and general weather terms are also addressed in this article. Some terms are specific to certain regions.
A blizzard warning is a hazardous weather statement issued by Weather Forecast Offices (WFO) of the National Weather Service (NWS) in the United States, which indicates heavy snowfall accompanied by sustained winds or frequent gusts of 35 mph (56 km/h) or greater are forecast to occur for a minimum of three hours. A blizzard tends to reduce visibilities to 1⁄4 mile (400 m) or less.
Tropical Cyclone Tam was the first named storm of the 2005–06 South Pacific cyclone season. Forming out of a tropical depression on January 6, the storm gradually intensified, becoming a tropical cyclone on January 12 and receiving the name Tam. Although it was traveling at a quick pace, the storm gained organization and reached its peak intensity with winds of 85 km/h (53 mph) the following day. However, the increasing forward motion of the storm, combined with strengthening wind shear, caused Tam to rapidly weaken on January 14. Around that time, it entered the Tropical Cyclone Warning Centre in Wellington, New Zealand's area of responsibility. Shortly thereafter, the storm transitioned into an extratropical cyclone and dissipated early the next day. Cyclone Tam produced heavy rainfall and strong winds over American Samoa upon being named. The precipitation caused several mudslides and flooding, which inflicted $26,000 in damage. The storm also had minor effects on Niue, Tonga, and Futuna.
The following is a glossary of tropical cyclone terms.
A hurricane force wind warning is a warning issued by the National Weather Service of the United States when sustained winds or frequent gusts of 64 knots or greater are either being observed or are predicted to occur. The winds must not be directly associated with a tropical cyclone, or a hurricane warning will be issued. If winds are lighter than 64 knots, a storm warning or gale warning will be issued. The hurricane force wind warning is only used to warn of the possibility of wind which reaches hurricane-level severity, but lacks direct connection with a hurricane system. The hurricane force wind can either signal sustained winds of 64 knots, or gusts of 64 knots lasting for two or more hours.
The November 2014 Bering Sea cyclone was the most intense extratropical cyclone ever recorded in the Bering Sea, which formed from a new storm developing out of the low-level circulation that separated from Typhoon Nuri, which soon absorbed the latter. The cyclone brought gale-force winds to the western Aleutian Islands and produced even higher gusts in other locations, including a 97 miles per hour (156 km/h) gust in Shemya, Alaska. The storm coincidentally occurred three years after another historic extratropical cyclone impacted an area slightly further to the east.
Hurricane Zeta was a late-season major hurricane in 2020 that made landfall on the Yucatán Peninsula and then in southeastern Louisiana, the latest on record to do so at such strength in the United States. Zeta was the record-tying sixth hurricane of the year to make landfall in the United States. The twenty-seventh named storm, twelfth hurricane and fifth major hurricane of the extremely active 2020 Atlantic hurricane season, Zeta formed from a broad area of low pressure that formed in the western Caribbean Sea on October 19. After battling wind shear, the quasi-stationary low organized into Tropical Depression Twenty-Eight on October 24. The system strengthened into Tropical Storm Zeta early on October 25 before becoming a hurricane the next day as it began to move northwestward. Hurricane Zeta made landfall on the Yucatán Peninsula late on October 26 and weakened while inland to a tropical storm, before moving off the northern coast of the peninsula on October 27. After weakening due to dry air entrainment, Zeta reorganized and became a hurricane again, and eventually a Category 2 hurricane, as it turned northeastward approaching the United States Gulf Coast on October 28. It continued to strengthen until it reached its peak intensity as a major Category 3 hurricane with 115-mile-per-hour (185 km/h) sustained winds and a minimum pressure of 970 mbar (28.64 inHg) as it made landfall at Cocodrie, Louisiana, that evening. Zeta continued on through Mississippi and parts of Alabama with hurricane-force winds. Zeta gradually weakened as it accelerated northeastward, and became post-tropical on October 29, as it moved through central Virginia, dissipating shortly afterwards off the coast of New Jersey. After bringing accumulating snow to parts of New England, the extratropical low-pressure system carrying Zeta's remnant energy impacted the United Kingdom on November 1 and 2.
