1.
1968 Atlantic hurricane season
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The 1968 Atlantic hurricane season was one of five Atlantic hurricane seasons during the satellite era not to feature a major hurricane, the others being 1972,1986,1994, and 2013. The season officially began on June 1 and lasted until November 30 and it was a below average season in terms of tropical storms, with a total of eight nameable storms. The first system, Hurricane Abby, developed in the northwestern Caribbean Sea on June 1, Abby moved northward and struck Cuba, bringing heavy rainfall and flooding to western portions of the island. Making landfall in Florida on June 4, Abby caused flooding and spawned four tornadoes, overall, the hurricane resulted in six deaths and about $450,000 in damage. In late June, Tropical Storm Candy brought minor flooding and spawned several tornadoes across portions of the Southern United States, overall damage from the cyclone reached approximately $2.7 million. Despite three named storms in June, cyclone activity slowed throughout the subsequent month, with one tropical depression. During late August and early September, Tropical Depression Eleven brought flooding to the Jacksonville area of Florida, Hurricane Gladys, the final and also the strongest named storm of the season, developed in the southwestern Caribbean Sea on October 13. Rough seas, gusty winds, tornadoes, and heavy rainfall resulted in minor impact in Florida. Gladys also provided relief for one of North Carolinas worst droughts, several other storms left negligible impact on land. Overall, the storms of the season collectively caused approximately $21.8 million in damage, the Atlantic hurricane season officially began on June 1, with Hurricane Abby developing that day. It was an average season in which eight tropical storms formed, compared to the 1966–2009 average of 11.3 named storms. Four of these reached hurricane status, slightly below the 1966–2009 average of 6.2, none of the hurricanes strengthened into a major hurricane, only four other seasons since the satellite era began featured no major hurricanes,1972,1986,1994, and 2013. Further, no hurricanes exceeded Category 1 intensity on the Saffir–Simpson hurricane wind scale, despite an active beginning, this season had the fewest hurricane days since 1962. Four hurricanes and one tropical storm made landfall during the season, causing 17 deaths, the last storm of the season, a tropical depression, dissipated on November 25, five days before the official end of hurricane season on November 30. Tropical cyclogenesis began in June, with three named storms during that month – hurricanes Abby and Brenda and Tropical Storm Candy – tying the record set in 1886,1936, despite the quick start, activity abruptly slowed, with only a tropical depression in July. The next named storm, Hurricane Dolly, existed from August 10 to August 17, September was the most active month, with five tropical depressions, two tropical storms, and one subtropical storm, which peaked with an intensity equivalent to a Category 1. In October, Hurricane Gladys became the strongest tropical cyclone of the season, despite maximum sustained winds of only 85 mph, the seasons activity was reflected with an accumulated cyclone energy rating of 45. It is only calculated for full advisories on tropical systems at or exceeding 39 mph, the interaction of a mid-tropospheric trough and a cold front spawned a tropical depression on June 1
2.
1968 Pacific hurricane season
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The 1968 Pacific hurricane season ties the record for having the most active August in terms of tropical storms. It officially started on May 15,1968, in the eastern Pacific and June 1 in the central Pacific and these dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean. Several notable systems formed during the season, five named storms—Hyacinth, Iva, Liza, Naomi, and Pauline—had effects in the United States. Two others—Annette and Tropical Depression Two—affected Mexico, and Tropical Storm Simone made a landfall on Guatemala. Tropical Storm Virginia, which formed in the West Pacific, crossed into the basin at a high latitude, of these, six remained depressions, thirteen peaked as tropical storms, and six reached hurricane strength. There were no major hurricanes this season, many of the tropical cyclones this season – including all six hurricanes – formed from Intertropical Convergence Zone disturbances. Eight tropical storms formed in August this year, a record for the most active August in the East Pacific, the eight named storms forming in August this year also made it the most tropical storms to ever form in a month in the East Pacific since 1966. However, this record was tied during the 2009 Pacific hurricane season, because of a lack of Hurricane Hunter data, a majority of the intensity readings from this season were later removed from the best track file. Even though the James Lykes noted that an area of disturbed weather south of the Pacific coast of Mexico was poorly organized and it made landfall and dissipated near Manzanillo on June 22. The satellite that was orbiting over Annette never took a picture with the storm in view since the storm was usually at the edge of the satellite. A computerized mosaic showed a vortex with the center over land. Damage, if any, is not known, the first of a large group of tropical cyclones that developed from ITCZ disturbances this season, a low pressure center in the ITCZ rapidly developed late on July 3. Becoming a tropical storm on July 4, the received the name Bonny. The newly named storm tracked west-northwest for 24 hours before turning to the overnight on July 5 into July 6. As a result, winds of 60 mph were measured on Socorro Island, at this time, satellites revealed that cooler sea surface temperatures and stratus inflow were starting to take their toll on Bonny. The storm began a slow dissipation and, by the time a ship reported the status of the weakening storm. The storm dissipated on July 9, the remnant low of Bonny had no kinetic energy, causing the forecasters to note that it had a ragged appearance on satellite imagery. The disturbance that became Celeste was first noticed by the Eastern Pacific Hurricane Center on July 13, the disturbance slowly intensified, becoming a tropical depression on July 14 and reaching storm strength on the next day
3.
1966 Pacific typhoon season
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The 1966 Pacific typhoon season was an active season, with many tropical cyclones having severe impacts in China, Japan, and the Philippines. Throughout the year, storms were responsible for at least 997 fatalities and $377.6 million in damage, however and it is widely accepted that wind estimates in the Western North Pacific during the reconnaissance era prior to 1988 are subject to great error. In many cases, intensities were grossly overestimated due to a combination inadequate technology, additionally, methodologies for obtaining wind estimates have changed over the decades and is not the same today as in 1966. Many storms in 1966 received strength reductions as a result of study, however. Notably the number of typhoons, Category 3 equivalent or higher on the Saffir–Simpson hurricane wind scale, was reduced from eight to six. The western Pacific basin covers the Pacific Ocean, north of the equator, Storms that form east of the date line and north of the equator are called hurricanes, see 1966 Pacific hurricane season. Tropical Storms formed in the entire west Pacific basin were assigned a name by the Joint Typhoon Warning Center, the Japan Meteorological Agency also monitored systems in the basin, however, it was not recognized as the Regional Specialized Meteorological Center until 1968. 115 mph Typhoon Irma hit the eastern Samar on May 15 and it weakened over the island, but re-intensified rapidly to a 140 mph typhoon in the Sibuyan Sea before hitting Mindoro on the 17th. After weakening to a storm, Irma turned northward to hit western Luzon as a 95 mph typhoon on the 19th. It accelerated to the northeast, and became extratropical on the 22nd, the extratropical remnant raced northeast before abruptly slowing on May 23 well to the east of Japan. During that time, it turned north while moving erratically. The system later acquired a general eastward track by May 26, severe damage took place across the Philippines, with Leyte suffering the brunt of Irmas impact. Twenty people lost their lives across the country, preliminary reports indicated that Tacloban incurred $2.5 million in damage. A gasoline explosion near Manila that killed 12 people and injured 18 others was partially attributed to the typhoon. On May 17, the 740 ton vessel Pioneer Cebu sailed directly into the storm over the Visayan Sea off the coast of Malapascua Island after ignoring warnings to remain at port, carrying 262 people, the ship struck a reef while battling rough seas in the typhoon. Passengers began abandoning the vessel soon thereafter under the captains orders while message about the ships sinking was relayed by the radio operator. A large wave struck the ship on its side, capsizing and submerging it entirely. Of the passengers and crew,122 went down with the ship, including captain Floro Yap, rescue operations lasted nearly two days, with many of the survivors being stranded in shark infested waters for upwards of 40 hours
4.
1967 Pacific typhoon season
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The 1967 Pacific typhoon season has no official bounds, it ran year-round in 1967, 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, the scope of this article is limited to the Pacific Ocean, north of the equator and west of the international date line. Storms that form east of the line and north of the equator are called hurricanes. Tropical Storms formed in the entire west pacific basin were assigned a name by the Joint Typhoon Warning Center, Tropical depressions in this basin have the W suffix added to their number. Tropical depressions that enter or form in the Philippine area of responsibility are assigned a name by the Philippine Atmospheric and this can often result in the same storm having two names. During the 1967 Pacific typhoon season,40 tropical depressions formed, twenty tropical storms attained typhoon intensity, and five of the typhoons reached super typhoon intensity. Typhoon Violet, which formed on April 1, steadily weakened from its peak of 140 mph to directly impact northeastern Luzon as a 115 mph typhoon on the 8th and it dissipated in the South China Sea on April 12 without causing any significant damage. Typhoon Billie, having developed on July 2, reached its peak of 85 mph on July 5, a cold core low developed tropical characteristics and became Tropical Depression 8W on July 6. It tracked westward, becoming a storm later that day. After briefly weakening to a storm, Clara re-attained typhoon status. Clara weakened to a 90 mph typhoon just before hitting Taiwan on the 11th, claras heavy rains caused 69 fatalities and a further 32 people to be reported as missing. Super Typhoon Opal was a system that peaked in winds of 180 miles per hour. On September 14, Tropical Storm Sarah, which formed across the International Date Line, immediately after the first advisory following Sarahs entrance into the West Pacific, it was upgraded to a minimal typhoon. Typhoon Sarah continued to intensify, and late on September 15, the next day, Sarah reached its peak intensity, attaining 150 mph winds and a 932 millibar pressure reading, making the system a super typhoon. Sarah began gradually weakening afterwards, and late on September 21, it became extratropical, on September 16, Sarah made landfall on Wake Island at peak intensity, causing widespread damage. Coincidentally, Olives attack on the island occurred on September 16, Carla became an intense typhoon while located in the Philippine Sea on October 15. During its weakening stage, the typhoon dumped extreme rainfall around its circulation, Typhoon Emma was the second super Typhoon to hit the Philippines in just weeks after Typhoon Carla. Typhoon Emma left 300 people dead and 60 others missing 1967 Atlantic hurricane season 1967 Pacific hurricane season Japan Meteorological Agency Joint Typhoon Warning Center
5.
1969 Pacific typhoon season
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The 1969 Pacific typhoon season was the third least-active season on record. The season had no bounds, it ran year-round in 1969. These dates conventionally delimit the period of each year when most tropical cyclones form in the northwestern Pacific Ocean, the scope of this article is limited to the Pacific Ocean, north of the equator and west of the international date line. Storms that form east of the line and north of the equator are called hurricanes. Tropical Storms formed in the entire west pacific basin were assigned a name by the Joint Typhoon Warning Center, Tropical depressions in this basin have the W suffix added to their number. Tropical depressions that enter or form in the Philippine area of responsibility are assigned a name by the Philippine Atmospheric and this can often result in the same storm having two names. 34 tropical depressions formed this year in the Western Pacific, of which 23 became tropical storms,13 storms reached typhoon intensity, of which 2 reached super typhoon strength. Large Super Typhoon Viola, which formed on July 22 east of the Philippines and it continued to the northwest, and weakened due to lack of inflow. Viola hit southeastern China as a typhoon on the 28th. The typhoon caused more than 1000 deaths in and around Shantou, Guangdong, China, on September 19, Tropical Depression 14W formed over the open Western Pacific. It tracked almost due westward, becoming a storm on the 20th. Elsie continued to intensify, and reached a peak of 175 mph winds on the 24th, after peaking, the typhoon steadily weakened as it moved westward. On the 26th 105 mph Typhoon Elsie hit northern Taiwan, after drifting northward, Elsie dissipated over China on September 28. The typhoon killed 102 people, with 24 missing and 227 injured from the system, just days after Elsie hit Taiwan, Tropical Storm Flossie approached Taiwan. From October 1 to the 5th, it drifted northward offshore of the island and it accelerated to the northeast, and became extratropical on the 10th east of Japan. Flossies heavy rains left 75 people dead, Western North Pacific tropical cyclones were named by the Joint Typhoon Warning Center. The first storm of 1969 was named Phyllis and the one was named Marie. Japan Meteorological Agency Joint Typhoon Warning Center
6.
1970 Pacific typhoon season
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The 1970 Pacific typhoon season has no official bounds, it ran year-round in 1970, 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, the scope of this article is limited to the Pacific Ocean, north of the equator and west of the international date line. Storms that form east of the line and north of the equator are called hurricanes. Tropical Storms formed in the entire west Pacific basin were assigned a name by the Joint Typhoon Warning Center, Tropical depressions in this basin have the W suffix added to their number. Tropical depressions that enter or form in the Philippine area of responsibility are assigned a name by the Philippine Atmospheric and this can often result in the same storm having two names. 27 tropical depressions formed this year in the Western Pacific, of which 24 became tropical storms,12 storms reached typhoon intensity, of which 7 reached super typhoon strength. Nancy originated from the interaction between an active ITCZ and a front near the Caroline Islands and the equator in mid February. An increase in convection was shown by weather satellites on February 18, the depression moved west, suppressed south by a high pressure ridge to the north, and gradually strengthened into a tropical storm and was given the name Nancy early on February 20. Nancy became a typhoon on the 22 about 100 miles northwest from Woleai, on February 23 Nancy passed to the north of Yap where strong gale winds occurred. Continuing to encounter more favorable conditions Nancy was able to achieve a peak intensity of 140 mph and this was the equivalent of a category four hurricane. It is rare to have a typhoon of this magnitude during the month of February, as noted by the JTWC, only Irma of the 1953 season reached the same intensity at the time. As Nancy approached the Philippine Islands the typhoon traversed to the ambit of the ridge that had kept it to the south. During the 25 Nancy passed east off the coast of the easternmost islands of the Philippines, on the island of Catanduanes, the edge of the eye brushed the eastern coast. A U. S. Coast Guard loran station on Catanduanes recorded intense winds, the storm encountered a hostile environment to the northeast of Luzon and began to weaken. By February 26 Nancy had become a storm and shortly afterward had transitioned into an extra tropical cyclone. By the 28 what remained of Nancy was a frontal trough, Nancy caused significant damage to the Philippines and surrounding islands. Particularly hard hit were the islands of Catanduanes and Samar, damage was estimated near a million dollars with 5,000 families homeless. On the Island of Yap heavy storm surge caused $160,000 in damages, a 6,065 ton American ship, Antinous, encountered the full brunt of the typhoon shortly before midnight, February 24
7.
Bar (unit)
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The bar is a metric unit of pressure, but is not approved as part of the International System of Units. It is defined as equal to 100000 Pa, which is slightly less than the current average atmospheric pressure on Earth at sea level. The bar and the millibar were introduced by the Norwegian meteorologist Vilhelm Bjerknes, use of the bar is deprecated by some professional bodies in some fields. The International Astronomical Union also lists it under Non-SI units and symbols whose continued use is deprecated, as of 2004, the bar is legally recognized in countries of the European Union. Units derived from the bar include the megabar, kilobar, decibar, centibar, the notation bar, though deprecated by various bodies, represents gauge pressure, i. e. pressure in bars above ambient or atmospheric pressure. The bar is defined using the SI derived unit, pascal,1 bar ≡100000 Pa. Thus,1 bar is equal to,100 kPa 1×105 N/m21000000 Ba, notes,1 millibar =1 one-thousandth bar, or 1×10−3 bar 1 millibar =1 hectopascal. The word bar has its origin in the Greek word βάρος, the units official symbol is bar, the earlier symbol b is now deprecated and conflicts with the use of b denoting the unit barn, but it is still encountered, especially as mb to denote the millibar. Between 1793 and 1795, the bar was used for a unit of weight in an early version of the metric system. Atmospheric air pressure is given in millibars where standard sea level pressure is defined as 1013 mbar,101.3,1.013 bar. Despite the millibar not being an SI unit, meteorologists and weather reporters worldwide have long measured air pressure in millibars as the values are convenient, for example, the weather office of Environment Canada uses kilopascals and hectopascals on their weather maps. In contrast, Americans are familiar with the use of the millibar in US reports of hurricanes, in fresh water, there is an approximate numerical equivalence between the change in pressure in decibars and the change in depth from the water surface in metres. Specifically, an increase of 1 decibar occurs for every 1.019716 m increase in depth, in sea water with respect to the gravity variation, the latitude and the geopotential anomaly the pressure can be converted into meters depth according to an empirical formula. As a result, decibars are commonly used in oceanography, many engineers worldwide use the bar as a unit of pressure because, in much of their work, using pascals would involve using very large numbers. In the automotive field, turbocharger boost is often described in bars outside the USA), unicode has characters for mb and bar, but they exist only for compatibility with legacy Asian encodings and are not intended to be used in new documents. The kilobar, equivalent to 100 MPa, is used in geological systems. Bar and bara are sometimes used to indicate absolute pressures and bar and this usage is deprecated and fuller descriptions such as gauge pressure of 2 bar or 2 bar gauge are recommended.0 Unported License but not under the GFDL. Non-SI units accepted for use with the SI
8.
Japan Meteorological Agency
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The Japan Meteorological Agency, frequently abbreviated to JMA, is an agency of the Ministry of Land, Infrastructure, Transport and Tourism. Its headquarters is located in Chiyoda, Tokyo, JMA is responsible for gathering and reporting weather data and forecasts for the general public, as well as providing aviation and marine weather. JMA other responsibilities include issuing warnings for volcanic eruptions, and the issuance of earthquake warnings of the Earthquake Early Warning system. JMA is also designated one of the Regional Specialized Meteorological Centers of the World Meteorological Organization, august 26,1872 – The first weather station in Japan set up in Hakodate, Hokkaido. It is the precursor of the present Hakodate Weather Station, June 1875 – The original Tokyo Meteorological Observatory was formed within the Survey Division of Geography Bureau of Home Ministry. January 1,1887 – The Tokyo Meteorological Observatory was renamed as the Central Meteorological Observatory, april 1895 – The Ministry of Education replaced the preceding ministry as an administrator of the Observatory. January 1,1923 – The main office moved to Motoe-machi, Kōjimachi-ku, November 1943 – The Ministry of Transport and Communications took over the CMOs operation. May 1945 – It became part of the Ministry of Transport, july 1,1956 – The Central Meteorological Observatory became an agency of the Ministry of Transport, and has been renamed to the Japan Meteorological Agency. March 1964 – The headquarters office was relocated to the present building in Ōtemachi, january 6,2001 – The JMA becomes an agency of the Ministry of Land, Infrastructure, Transport and Tourism with the Japanese government reformation. 2013 – It has been announced that it would be scheduled to move the headquarters into Toranomon, the JMA is responsible not only for gathering and reporting weather data and forecasts in Japan, but also for observation and warning of earthquakes, tsunamis, typhoons and volcanic eruptions. The agency has six administrative offices, four Marine Observatories, five auxiliary facilities. These are also used to gather data, supplemented by weather satellites such as Himawari, in 1968, the World Meteorological Organization designated the JMA as a Regional Specialized Meteorological Centre for Asia. In June 1988, the WMO also assigned the JMA as a RSMC for the Northwestern Pacific under its Tropical Cyclone programme, each DMO and LMO issues weather forecasts and warnings or advisories to the general public live in its own area. Weather data used to these forecasts are acquired from the Surface Observation, the Radar Observation, the Upper-air Observation, the Marine Observatories are seated in Hakodate, Maizuru, Kobe and Nagasaki. These stations observe ocean waves, tide levels, sea surface temperature, along with this establishment, JMA placed the Air Traffic Meteorology Center inside the ATMC. Additionally, Aviation Weather Stations deal with the similar tasks as these, in the Northwestern Pacific area, the typhoon season ordinarily comes almost from May to November. The JMA forecasts and warns or advises on tropical cyclones to the public in Japan, the JMA has its own 624 observation stations across the country that set up at intervals of 20 km approximately in order to measure seismic intensity of earthquakes precisely. The agency also utilize about 2,900 more seismographs owned by the National Research Institute for Earth Science and Disaster Prevention, the Earthquake Early Warning system began to work fully for the general public on October 1,2007
9.
Pacific hurricane
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A Pacific hurricane is a mature tropical cyclone that develops within the eastern and central Pacific Ocean to the east of 180°W, north of the equator. Identical phenomena in the western north Pacific are called typhoons and this separation between the two basins has a practical convenience, however, as tropical cyclones rarely form in the central north Pacific and few cross the dateline. Documentation of Pacific hurricanes dates to the Spanish colonization of Mexico, in 1730, such accounts indicated an understanding of the storms. Between June and October 1850, Redfield observed five tropical cyclones along the southwestern coast of North America, in 1895, Cleveland Abbe reported the presence of many storms between 5° to 15°–N in the eastern Pacific, although many such storms dissipated before affecting the Mexican coast. Two years later, the German Hydrography Office Deutsche Seewarte documented 45 storms from 1832 to 1892 off the west coast of Mexico, despite the documentation of storms in the region, the official position of the United States Weather Bureau denied the existence of such storms. After California became a state and the discovery of gold there in 1848, such activity increased further after the Panama Canal opened in 1914, and the shipping lanes moved closer to the coast. By around 1920, Pacific hurricanes were officially recognized due to widespread ship observations, radio service, within 60 years, further studies of the regions tropical activity indicated that the eastern Pacific was the second most active basin in the world. During the 1920s, a few documents in the Monthly Weather Review reported additional storms within 2,000 mi off the Mexican coastline. The database was based on records held by the United States Navy and were interpolated from 12 hourly intervals to 6 hourly intervals based on a scheme devised by Hiroshi Akima in 1970. Initially tracks for the Central Pacific region and tracks for tropical depressions that did not develop into tropical storms or hurricanes were not included within the database, the archives format was significantly changed during 2013 to include non-synoptic best track times, non-developing tropical depressions and wind radii. During February 2016, the NHC released the 1959 Mexico hurricanes reanalysis and its effects in the central Pacific basin are usually related to keeping cyclones away from the Hawaiian Islands. Due to westward trade winds, hurricanes in the Pacific rarely head eastward, a second factor preventing tropical cyclones from forming during the winter is the occupation of a semi-permanent low-pressure area designated the Aleutian Low between January and April. Its presence over western Canada and the northwestern United States contributes to the occurrences of precipitation in that duration. In addition, its effects in the central Pacific near 160° W causes tropical waves form in the area to drift northward into the Gulf of Alaska. The retreat of this low allows the Pacific High to also retreat into the central Pacific, leaving a warm, Hurricane season runs between May 15 and November 30 each year. These dates encompass the vast majority of tropical activity in this region. The Regional Specialized Meteorological Center for this basin is the United States National Hurricane Center, previous forecasters are the Eastern Pacific Hurricane Center and the Joint Hurricane Warning Center. The RSMC monitors the eastern Pacific and issues reports, watches and warnings about tropical weather systems and this area is, on average, the second-most active basin in the world
10.
Joint Typhoon Warning Center
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The Joint Typhoon Warning Center is a joint United States Navy – United States Air Force command located in Pearl Harbor, Hawaii. Their warnings are intended for the protection of military ships. At this time the centre was one of three Navy and two Air Force units responsible for tropical cyclone reconnaissance and warnings in the Pacific, over the next few years the coordination of tropical warnings between the centres was at times difficult or impossible due to various communication problems. A committee was set up to study the issue which issued a report during January 1959. The CINCPAC subsequently petitioned the Joint Chiefs of Staff, who gave permission for the centre to be set up effective May 1,1959, the JTWC initially consisted of ten people with two officers and three enlisted personnel provided by each service. It was required to provide warnings on all tropical cyclones, between the Malay Peninsular and the International Dateline for US government agencies and they also had to determine reconnaissance requirements, prepare annual typhoon summaries, and conduct research into tropical cyclone forecasting and detection. In November 1962, Typhoon Karen destroyed the housing the Fleet Weather Center/Joint Typhoon Warning Center. It relocated in a more typhoon-proof building in 1965, between 1971 and 1976, CINCPAC gradually expanded out the JTWCs area of responsibility, to include the area between the International Dateline and the African coasts. The JTWC subsequently started issuing warnings for the Southern Hemisphere between the African coast and the International Dateline during October 1980 and it was relocated to Pearl Harbor on January 1,1999 due to the 1995 Base Realignment and Closure Commission round. A more modernized method for forecasting tropical cyclones had become apparent by the 1980s, prior to the development of ATCF, the tools used by the Department of Defense to forecast tropical cyclone track were acetate, grease pencils, and disparate computer programs. The ATCF software was developed by the Naval Research Laboratory for the JTWC beginning in 1986 and it was adapted for use at the National Hurricane Center in 1990. S. Standard of measuring sustained winds for 1-min instead of the 10-min span recommended by the WMO, JTWC monitors, analyzes, and forecasts tropical cyclone formation, development, and movement year round. Its area of responsibility covers 89% of the tropical cyclone activity. The Center is manned by about 37 U. S. Air Force and Navy personnel. The JTWC uses several satellite systems and sensors, radar, surface and upper level synoptic data as well as models to complete its mission. pgtw, wtps3#. pgtw, wtpn3#. pgtw
11.
Pascal (unit)
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The pascal is the SI derived unit of pressure used to quantify internal pressure, stress, Youngs modulus and ultimate tensile strength. It is defined as one newton per square meter and it is named after the French polymath Blaise Pascal. Common multiple units of the pascal are the hectopascal which is equal to one millibar, the unit of measurement called standard atmosphere is defined as 101,325 Pa and approximates to the average pressure at sea-level at the latitude 45° N. Meteorological reports typically state atmospheric pressure in hectopascals, the unit is named after Blaise Pascal, noted for his contributions to hydrodynamics and hydrostatics, and experiments with a barometer. The name pascal was adopted for the SI unit newton per square metre by the 14th General Conference on Weights, one pascal is the pressure exerted by a force of magnitude one newton perpendicularly upon an area of one square metre. The unit of measurement called atmosphere or standard atmosphere is 101325 Pa and this value is often used as a reference pressure and specified as such in some national and international standards, such as ISO2787, ISO2533 and ISO5024. In contrast, IUPAC recommends the use of 100 kPa as a standard pressure when reporting the properties of substances, geophysicists use the gigapascal in measuring or calculating tectonic stresses and pressures within the Earth. Medical elastography measures tissue stiffness non-invasively with ultrasound or magnetic resonance imaging, in materials science and engineering, the pascal measures the stiffness, tensile strength and compressive strength of materials. In engineering use, because the pascal represents a small quantity. The pascal is also equivalent to the SI unit of energy density and this applies not only to the thermodynamics of pressurised gases, but also to the energy density of electric, magnetic, and gravitational fields. In measurements of sound pressure, or loudness of sound, one pascal is equal to 94 decibels SPL, the quietest sound a human can hear, known as the threshold of hearing, is 0 dB SPL, or 20 µPa. The airtightness of buildings is measured at 50 Pa, the units of atmospheric pressure commonly used in meteorology were formerly the bar, which was close to the average air pressure on Earth, and the millibar. Since the introduction of SI units, meteorologists generally measure pressures in hectopascals unit, exceptions include Canada and Portugal, which use kilopascals. In many other fields of science, the SI is preferred, many countries also use the millibar or hectopascal to give aviation altimeter settings. In practically all fields, the kilopascal is used instead. Centimetre of water Metric prefix Orders of magnitude Pascals law
