The National Hurricane Center (NHC) is the division of the United States' NOAA/National Weather Service responsible for tracking and predicting tropical weather systems between the Prime Meridian and the 140th meridian west poleward to the 30th parallel north in the northeast Pacific Ocean and the 31st parallel north in the northern Atlantic Ocean. The agency, which is co-located with the Miami branch of the National Weather Service, is situated on the campus of Florida International University in University Park, Florida.
The National Weather Service (NWS) is an agency of the United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the purposes of protection, safety, and general information. It is a part of the National Oceanic and Atmospheric Administration (NOAA) branch of the Department of Commerce, and is headquartered in Silver Spring, Maryland, within the Washington metropolitan area. The agency was known as the United States Weather Bureau from 1890 until it adopted its current name in 1970.
Sea surface temperature (SST), or ocean surface temperature, is the water temperature close to the ocean's surface. The exact meaning of surface varies according to the measurement method used, but it is between 1 millimetre (0.04 in) and 20 metres (70 ft) below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a short distance of the shore. Localized areas of heavy snow can form in bands downwind of warm water bodies within an otherwise cold air mass. Warm sea surface temperatures are known to be a cause of tropical cyclogenesis over the Earth's oceans. Tropical cyclones can also cause a cool wake, due to turbulent mixing of the upper 30 metres (100 ft) of the ocean. SST changes diurnally, like the air above it, but to a lesser degree. There is less SST variation on breezy days than on calm days. In addition, ocean currents such as the Atlantic Multidecadal Oscillation (AMO), can effect SST's on multi-decadal time scales, a major impact results from the global thermohaline circulation, which affects average SST significantly throughout most of the world's oceans.
The Atlantic hurricane season is the period in a year from June through November when hurricanes usually form in the Atlantic Ocean. Tropical cyclones in the North Atlantic are called hurricanes, tropical storms, or tropical depressions. In addition, there have been several storms over the years that have not been fully tropical and are categorized as subtropical depressions and subtropical storms. Even though subtropical storms and subtropical depressions are not technically as strong as tropical cyclones, the damages can still be devastating.
A Pacific hurricane is a mature tropical cyclone that develops within the northeastern and central Pacific Ocean to the east of 180°W, north of the equator. For tropical cyclone warning purposes, the northern Pacific is divided into three regions: the eastern, central, and western, while the southern Pacific is divided into 2 sections, the Australian region and the southern Pacific basin between 160°E and 120°W. Identical phenomena in the western north Pacific are called typhoons. This separation between the two basins has a practical convenience, however, as tropical cyclones rarely form in the central north Pacific due to high vertical wind shear, and few cross the dateline.
The 1961 Pacific typhoon season had no official bounds; it ran year-round in 1961, but most tropical cyclones tend to form in the northwestern Pacific Ocean between June and December. These dates conventionally delimit the period of each year when most tropical cyclones form in the northwestern Pacific Ocean.
Weather buoys are instruments which collect weather and ocean data within the world's oceans, as well as aid during emergency response to chemical spills, legal proceedings, and engineering design. Moored buoys have been in use since 1951, while drifting buoys have been used since 1979. Moored buoys are connected with the ocean bottom using either chains, nylon, or buoyant polypropylene. With the decline of the weather ship, they have taken a more primary role in measuring conditions over the open seas since the 1970s. During the 1980s and 1990s, a network of buoys in the central and eastern tropical Pacific Ocean helped study the El Niño-Southern Oscillation. Moored weather buoys range from 1.5–12 metres (5–40 ft) in diameter, while drifting buoys are smaller, with diameters of 30–40 centimetres (12–16 in). Drifting buoys are the dominant form of weather buoy in sheer number, with 1250 located worldwide. Wind data from buoys has smaller error than that from ships. There are differences in the values of sea surface temperature measurements between the two platforms as well, relating to the depth of the measurement and whether or not the water is heated by the ship which measures the quantity.
Traditionally, areas of tropical cyclone formation are divided into seven basins. These include the north Atlantic Ocean, the eastern and western parts of the northern Pacific Ocean, the southwestern Pacific, the southwestern and southeastern Indian Oceans, and the northern Indian Ocean. The western Pacific is the most active and the north Indian the least active. An average of 86 tropical cyclones of tropical storm intensity form annually worldwide, with 47 reaching hurricane/typhoon strength, and 20 becoming intense tropical cyclones, super typhoons, or major hurricanes.
The Climate Prediction Center (CPC) is a United States federal agency that is one of the National Centers for Environmental Prediction, which are a part of the National Oceanic and Atmospheric Administration's National Weather Service. CPC is headquartered in College Park, Maryland. Its roots trace back to the late 18th century, with the United States Army Signal Corp taking over responsibility of the climate program in the late 19th century. Once it became part of the United States Weather Bureau, it was known as the Weather Bureau Climate and Crop Services. From 1957 through 1966, the United States Weather Bureau's Office of Climatology, located in Washington, D.C. and then Suitland, Maryland, published the Mariners Weather Log publication. Late in the 20th century, it was known as the Climate Analysis Center for a time, before evolving into CPC in 1995. CPC issues climate forecasts valid for weeks and months in advance.
The Hurricane Databases (HURDAT), managed by the National Hurricane Center, are two separate databases that contain details on tropical cyclones, that have occurred within the Atlantic Ocean and Eastern Pacific Ocean since 1851 and 1949 respectively.
The Ocean Prediction Center (OPC), established in 1995, is one of the National Centers for Environmental Prediction's (NCEP's) original six service centers. Until 2003, the name of the organization was the Marine Prediction Center. Its origins are traced back to the sinking of the RMS Titanic in 1912. The OPC issues forecasts up to five days in advance for ocean areas north of 31° north latitude and west of 35° west longitude in the Atlantic, and across the northeast Pacific north of 30° north latitude and east of 160° east longitude. Until recently, the OPC provided forecast points for tropical cyclones north of 20° north latitude and east of the 60° west longitude to the National Hurricane Center. OPC is composed of two branches: the Ocean Forecast Branch and the Ocean Applications Branch.
Tropical Storm Kirsten was the eighth tropical cyclone of the 1966 Pacific hurricane season and the second to make landfall in the Baja California peninsula. Forming north of the Intertropical Convergence Zone (ITCZ), Kirsten developed into a tropical depression on September 25 and like Tropical Storm Joyce of the same season, took a long period of time before intensifying into a tropical storm.
The International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is a digital database of 261 million weather observations made by ships, weather ships, and weather buoys spanning the years 1662 to 2007. The database was initially constructed in 1985 and continues to be expanded upon and updated on a regular basis. From the original data, gridded datasets were created. ICOADS information has been useful in determining the reliability of ship and buoy wind measurements, helping to determine temperature trends in the sea surface temperature field, and updating the Atlantic hurricane database.
Hurricane Hilary was a Category 3 hurricane that caused significant flooding in the Midwestern United States in August 1993. A westward moving tropical depression gradually developed on August 17 south of the Mexican coast, attaining hurricane status two days later. The storm further intensified into a Category 3 hurricane, attaining peak winds of 120 mph (195 km/h). By August 23, the hurricane nearly stalled while interacting with Tropical Storm Irwin. Executing a small counter-clockwise loop, Hilary degraded to tropical storm intensity and took a northerly track for the remainder of its existence. The storm made two landfalls in Mexico, one in Baja California Sur on August 25 and one in Sonora the following day. Tropical cyclone warnings and watches were issued for much of the southern Mexican coastline; however, they were later discontinued when the threat ended, but were issued again when the system posed a threat to the Baja California Peninsula. Hilary dropped in excess of 5 in (130 mm) rain along its path in some areas, and flash flooding in California and Iowa.
The history of Atlantic tropical cyclone warnings details the progress of tropical cyclone warnings in the north Atlantic Ocean. The first service was set up in the 1870s from Cuba with the work of Father Benito Viñes. After his death, hurricane warning services were assumed by the US Army Signal Corps and United States Weather Bureau over the next few decades, first based in Jamaica and Cuba before shifting to Washington, D.C.. The central office in Washington, which would evolve into the National Meteorological Center and the Weather Prediction Center, assumed the responsibilities by the early 20th century. This responsibility passed to regional hurricane offices in 1935, and the concept of the Atlantic hurricane season was established in order to keep a vigilant lookout for tropical cyclones during certain times of the year. Hurricane advisories issued every 12 hours by the regional hurricane offices began at this time.
Marine weather forecasting is the process by which mariners and meteorological organizations attempt to forecast future weather conditions over the Earth's oceans. Mariners have had rules of thumb regarding the navigation around tropical cyclones for many years, dividing a storm into halves and sailing through the normally weaker and more navigable half of their circulation. Marine weather forecasts by various weather organizations can be traced back to the sinking of the Royal Charter in 1859 and the RMS Titanic in 1912.
